Dioxin and heavy-metal contamination of shellfish and sediments in St. Louis Bay, Mississippi and adjacent marine waters.ABSTRACT Dioxins, furans, and trace metals were evaluated in shellfish shellfish, popular name for certain edible mollusks (see Mollusca), e.g., oysters, clams, and scallops, and for certain edible crustaceans, e.g., crabs, lobsters, and shrimps. All are aquatic invertebrates with shells; they are not fish. and sediments from St. Louis Bay, Mississippi and adjacent waters of Mississippi Sound Mississippi Sound, arm of the Gulf of Mexico, c.100 mi (160 km) long and from 7 to 15 mi (11–24 km) wide, extending from Lake Borgne in Louisiana on the west to Mobile Bay in Alabama on the east. . Highest concentrations and the most toxic dioxin dioxin
Aromatic compound, any of a group of contaminants produced in making herbicides (e.g., Agent Orange), disinfectants, and other agents. Their basic chemical structure consists of two benzene rings connected by a pair of oxygen atoms; when substituents on the rings are congener congener /con·ge·ner/ (kon´je-ner) something closely related to another thing, as a member of the same genus, a muscle having the same function as another, or a chemical compound closely related to another in composition and exerting were found in St. Louis Bay sediments in closest proximity to the effluent outfall out·fall
The place where a sewer, drain, or stream discharges.
Brit, Austral & NZ the mouth of a river, drain, or pipe: from the titanium dioxide refinery on the northern shore of the bay. Using conservative assumptions, we estimated the dioxin and furan furan: see furfural. burden of 17 measured congeners in St. Louis Bay sediments to be between 3.72 and 6.16 kg. Comparison of lipid-adjusted dioxins and furans in oysters (Crassostrea virginica) from this study with those collected from seafood markets and grocery stores in southern Mississippi in 1997 shows dioxin and furan contamination about 1.7 to 8 times higher in the samples from this study, depending on collection location. Oysters from St. Louis Bay and adjacent marine waters may accumulate higher concentrations of dioxins and furans than measured here, at other times during the year, due to the low lipid content of oysters in this single-season study. At other times, with typical higher oyster lipid levels, the dioxin content of oysters could increase by a factor of 8.5 to 12.7 times, commensurate with the expected increase in oyster lipids, although the rate of uptake of these contaminants is not known. Certain trace metals have increased markedly in St. Louis Bay shellfish since a 1978 baseline study that was conducted prior to the operation of the titanium dioxide refinery that produces large quantities of soluble waste metals such as chromium chromium (krō`mēəm) [Gr.,=color], metallic chemical element; symbol Cr; at. no. 24; at. wt. 51.996; m.p. about 1,857°C;; b.p. 2,672°C;; sp. gr. about 7.2 at 20°C;; valence +2, +3, +6. , nickel, and lead. In 2004, the percent value of chromium in oysters in St. Louis Bay was at least 1,167% greater than the 1978 values, and the percent value for nickel in oysters in the bay was at least 467% greater than the 1978 value. The percent value for chromium in 2004 from oysters outside the bay was between 7,700% and 11,300% greater than the 1978 reported in bay values. Rangia clams (Rangia cuneata) from St. Louis Bay tended to have greater increases than did oysters for all metals measured above detection limits in both studies, except for zinc, which declined in both shellfish species. Metals also increased in sediments, but soluble metals which are produced by, and apparently released from, the titanium dioxide refinery may be flushed out of the bay to higher salinity seawater seawater
Water that makes up the oceans and seas. Seawater is a complex mixture of 96.5% water, 2.5% salts, and small amounts of other substances. Much of the world's magnesium is recovered from seawater, as are large quantities of bromine. before becoming adsorbed on fine silt and clay-size particles which are consumed by shellfish and/or deposited in sediments. Oysters from waters near the mouth of St. Louis Bay were also contaminated contaminated,
v 1. made radioactive by the addition of small quantities of radioactive material.
2. made contaminated by adding infective or radiographic materials.
3. an infective surface or object. with dioxins, furans, and heavy metals heavy metals,
n.pl metallic compounds, such as aluminum, arsenic, cadmium, lead, mercury, and nickel. Exposure to these metals has been linked to immune, kidney, and neurotic disorders. . Based on widely published estimated safe and adequate daily dietary intake for chromium and nickel (the latter standard for hypersensitive hy·per·sen·si·tive
Responding excessively to the stimulus of a foreign agent, such as an allergen; abnormally sensitive.
hy individuals) the values recorded in this study indicate that less than one oyster per day should be consumed from the open harvest site sampled in adjacent Mississippi Sound. An evaluation of other regional sources of dioxin and dioxin-like compounds and heavy metals was conducted using data reported to the United States Environmental Protection Agency "EPA" redirects here. For other uses see EPA (disambiguation) and Environmental Protection Agency.
The Environmental Protection Agency (EPA or sometimes USEPA . Because of the lack of other identifiable large sources of these contaminants, the transport dynamics of soluble metals and the occurrence of highest dioxin and dioxin-like compound concentrations near the titanium dioxide refinery outfall, we conclude that the refinery is the most likely and most significant source of the measured dioxins, dioxin-like compounds, chromium, and nickel contamination found in St. Louis Bay and adjacent marine waters of Mississippi Sound.
KEY WORDS: dioxin, furan, trace metals, chromium, nickel, St. Louis Bay, oysters
St. Louis Bay is a 3,860-ha elliptical-shaped, shallow embayment with a narrow entry to the western end of Mississippi Sound (Fig. 1). The bay receives freshwater input from 2 primary rivers, the Jourdan and the Wolf, and, according to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. a 1978 study (Lytle & Lytle 1982), suffered the least of all bays along the Mississippi coast from sources of anthropogenic an·thro·po·gen·ic
1. Of or relating to anthropogenesis.
2. Caused by humans: anthropogenic degradation of the environment. pollutants pollutants
see environmental pollution. . The study of Lytle and Lytle (1982) was part of a characterization of St. Louis Bay because of concerns about potential pollution resulting from the future placement and operation of a titanium dioxide refinery near the northern shore of the bay in 1979. The refinery is reported to produce quantities of dioxins, furans, PCBs, and heavy metal by-products as well as other hazardous chemicals, based on the refinery's annual reporting requirements to the United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. Environmental Protection Agency's Toxic Release Inventory (TRI TRI Toxics Release Inventory (US EPA)
TRI Touch Research Institute
TRI Taux de Rentabilité Interne (French: internal rate of return)
TRI Taux de Rentabilité Interne
TRI Tile Roofing Institute ) (USEPA USEPA United States Environmental Protection Agency 2003). Such by-products are injected into ground wells on the site, disposed of at on-site landfills, released as point source air emissions, fugitive air emissions, and surface water discharges according to the reporting data. There is an effluent pipe from the refinery, labeled as a sewer pipe on National Oceanic and Atmospheric Administration Noun 1. National Oceanic and Atmospheric Administration - an agency in the Department of Commerce that maps the oceans and conserves their living resources; predicts changes to the earth's environment; provides weather reports and forecasts floods and hurricanes and (NOAA NOAA
National Oceanic and Atmospheric Administration
Noun 1. NOAA - an agency in the Department of Commerce that maps the oceans and conserves their living resources; predicts changes to the earth's environment; ) nautical charts See: hydrographic chart. 11371 and 11372A (NOAA 2001; NOAA 2004), located on the northern shore of St. Louis Bay, and releases from this pipe may constitute a portion of the reported surface-water discharges. In addition, airborne emissions from the refinery could be deposited, in part, by settling into the marine waters of St. Louis Bay, surrounding tidal marshes A tidal marsh is a type of marsh that is found along coasts and estuaries of which the flooding characteristics are determined by the tidal movement of the adjacent estuary, sea or ocean . and the adjacent Mississippi Sound.
[FIGURE 1 OMITTED]
Based on the reported chemical production in close proximity to St. Louis Bay, the potential for release of a portion of the chemicals and their entry into the bay ecosystem and adjacent offshore marine waters, and the availability of the baseline study, we undertook the current study to assess the degree of contamination of marine shellfish and sediments in the bay and adjacent offshore waters of Mississippi Sound in the summer of 2004.
MATERIALS AND METHODS
Field Collection of Samples
Sediment and shellfish collections were made on July 11 and 12, 2004, from a 15.2-m length (50 foot) oyster dredging dredging, process of excavating materials underwater. It is used to deepen waterways, harbors, and docks and for mining alluvial mineral deposits, including tin, gold, and diamonds. vessel, the F/V F/V Fishing Vessel
F/V Frequency to Voltage Converter Nova Star, fitted with a 16 tooth oyster dredge a rake or small dragnet for bringing up oysters from the bottom of the sea.
See also: Oyster weighing about 265 kg, known as a Mississippi dredge. Samples were collected under permit from the Mississippi Department of Marine Resources inside St. Louis Bay, between US Highway 90 and the CSX CSX Chessie Seaboard Multiplier (railroad transportation company)
CSX Cayman Islands Stock Exchange
CSX Changsha, China (Airport Code)
CSX Cardiac-Specific Homeobox
CSX Seaboard Coastline Railroad railroad bridges at the mouth of the bay and in adjacent waters of Mississippi Sound outside of St. Louis Bay at the locations shown in Figure 2 and Figure 4 (see Fig. 4 later in text).
[FIGURES 2 & 4 OMITTED]
A GPS (global positioning system Global Positioning System: see navigation satellite.
Global Positioning System (GPS)
Precise satellite-based navigation and location system originally developed for U.S. military use. ) receiver (Garmin GPSMAP 76, WAAS-enabled) was used onboard Refers to a chip or other hardware component that is directly attached to the printed circuit board (motherboard). Contrast with offboard. See inboard. the sampling vessel for tracking the sampling vessel's path and marking sediment sampling station waypoints. The receiver was mounted vertically on the bow (Naut.) on that part of the horizon within 45° on either side of the line ahead.
See also: Bow of the vessel, as far as possible from all other electronics, to increase accuracy and reduce any possible interference. Observed accuracy was approximately 3.0 m. Track locations and time were automatically recorded about once per minute along all oyster-collection trawls. Waypoints and collection time were manually saved at appropriate locations. Tracks and waypoints were downloaded to a computer for plotting on digital versions of NOAA nautical charts 11371 and 11372A using GIS software This is a list of notable GIS software applications. See also the comparison of GIS software. Open source software
Most widely used open source applications:
The surface area of St. Louis Bay, north of the US Highway 90 bridge, south of Interstate Highway 10, including the adjacent tidal marshlands, was estimated using ArcView GIS software (ESRI (Environmental Systems Research Institute, Inc., Redlands, CA, www.esri.com) The world's leading developer of geographic information systems (GIS) software, including programs that plot ZIP codes and addresses, demographic information and detailed, color-coded data. , Redlands, California For other uses of the term "Redlands", see Redlands.
Redlands is a city in San Bernardino County, California, United States. As of the 2000 census, the city had a total population of 63,591. ).
Sediments collected in July 2004 were compared with samples that had earlier been analyzed as part of a 1984 Mississippi-Alabama SEA GRANT investigation. The 1984 study (see Isphording, 1985) encompassed the entire Mississippi Sound, as well as all adjacent bays (as well as Lake Borgne Lake Borgne is a lagoon in eastern Louisiana of the Gulf of Mexico. Its name comes from the French word, borgne, which means "one-eyed". Geography
The three large lakes, Maurepas, Pontchartrain, and Borgne cover 55% of the Pontchartrain Basin. , Louisiana). A total of 109 2-meter vibracores were collected, 6 of which were obtained in St. Louis Bay. Each was subjected to mineralogic analysis to determine the mineralogy mineralogy
Scientific study of minerals, including their physical properties, chemical composition, internal crystal structure, occurrence and distribution in nature, and origins or conditions of formation. of the clay-size (-4 [micro]m) fraction, using x-ray diffraction, chemical analysis, using a Perkin-Elmer Model 6500 ICP (1) (Internet Cache Protocol) A protocol used by one proxy server to query another for a cached Web page without having to go to the Internet to retrieve it. See CARP and proxy server. spectrophotometer spectrophotometer, instrument for measuring and comparing the intensities of common spectral lines in the spectra of two different sources of light. See photometry; spectroscope; spectrum. , carbon analysis, using a LECO carbon-sulphur analyzer, and sediment texture analysis. A bottom sediment texture map A two-dimensional image of a surface that is used to cover 3D objects. See texture mapping.
Applying a Texture Map
A 2D texture map is "draped" over a 3D object to create the required surface. of the Mississippi Sound was constructed by carrying out size analyses on the upper 10-cm portion of each core using ASTM ASTM
American Society for Testing and Materials method D 422-63 (also used in the present study). The size frequency distribution of each sediment sample was obtained and also a complete description of the measures of central tendency and dispersion. The same computer algorithm used to analyze the 1984 samples was similarly used to process sediment data for the July 2004 samples in order that meaningful comparisons could be made.
Shellfish Collection and Handling
Shellfish collected with the Mississippi dredge on or close to the substrate surface were brought on board and rinsed clean of visible sediments using ambient water at the end of each dredge collection. The objective was to collect American oysters (Crassostrea virginica, Gmelin 1791), but at a few locations incidental collections of common Rangia clams (Rangia cuneata G. B. Sowerby I, 1831) and hooked mussels (Ischadium recurvum Rafinesque 1820) were made. The shellfish were blotted dry and packed in aluminum foil Noun 1. aluminum foil - foil made of aluminum
aluminium foil, tin foil
foil - a piece of thin and flexible sheet metal; "the photographic film was wrapped in foil" (precleaned by treatment in a muffle oven for a minimum of 3 h at a minimum temperature of 450[degrees]C) and then packed inside plastic bags. The shellfish were cooled in heavily insulated in·su·late
tr.v. in·su·lat·ed, in·su·lat·ing, in·su·lates
1. To cause to be in a detached or isolated position. See Synonyms at isolate.
2. containers with frozen ice packs. At the end of each sampling day, small amounts of dry ice were added to the samples and a programmed temperature recorder (Optic Stowaway Temp, Onset Computer Corp., Bourne, Massachusetts Bourne is a town in Barnstable County, Massachusetts, United States. The population was 18,721 at the 2000 census.
For geographic and demographic information on specific parts of the town of Bourne, please see the articles on Bourne (CDP), Buzzards Bay, Monument Beach, ) was added to each container. All samples were shipped to the processing laboratory in Sequim, Washington Sequim (skwɪm) is a city in Clallam County, Washington, United States. The population was 4,334 at the 2000 census. It is located along the Dungeness River near the base of the Olympic Mountains. by overnight courier on July 13, 2004, for delivery on July 14. Temperature was maintained between 1[degree]C and 4[degrees]C in all containers. All samples were assigned a predetermined pre·de·ter·mine
v. pre·de·ter·mined, pre·de·ter·min·ing, pre·de·ter·mines
1. To determine, decide, or establish in advance: sample number and entered into a chain of custody The movement and location of physical evidence from the time it is obtained until the time it is presented in court.
Judges in bench trials and jurors in jury trials are obligated to decide cases on the evidence that is presented to them in court. logging system. The shellfish sample collection locations are shown in Figure 2 and Figure 3 and labeled in numerical order as collected. Some numerical sample designations were subdivided into sequential alphabetical designations (e.g., 7A and 7B) representing two or more dredge samples with a given sample number. Start and end points are labeled S and E, respectively. All sample transfers were accompanied by chain-of-custody documentation.
[FIGURE 3 OMITTED]
After processing, samples for dioxin and furan analysis were submitted to the analytical laboratory on July 19, 2004. Additional oysters from most collection sites were stored frozen and whole at the processing laboratory at -20[degrees]C for later possible analysis. Samples for metals analysis were submitted to the analytical laboratories between September 3 and October 27, 2004. Samples were collected according to protocols acceptable for both dioxin and metals analysis, as referenced in the following methods, but as an added precaution, control oysters from a non-industrialized site in Puget Sound Puget Sound (py`jĕt), arm of the Pacific Ocean, NW Wash., connected with the Pacific by Juan de Fuca Strait, entered through the Admiralty Inlet and extending in two arms c. , Washington were also processed using part or all of the dioxin-preparation procedure to verify that no artifact A distortion in an image or sound caused by a limitation or malfunction in the hardware or software. Artifacts may or may not be easily detectable. Under intense inspection, one might find artifacts all the time, but a few pixels out of balance or a few milliseconds of abnormal sound from the dioxin sample preparation process would affect the metals analysis.
Sediment Collection and Handling
Sediments were collected with a Petite Ponar grab sampler sampler, sample piece of needlework or embroidery, of silk, cotton, or worsted, for the preservation of some pattern or as an example of the ability of a child or a beginner. In museums and private collections there are samplers dating from as early as 1643. , precleaned with Alconox Laboratory Detergent (Alconox Corp., White Plains, New York For other places with the same name, see White Plains (disambiguation).
White Plains is a city in south-central Westchester County, New York, about 4 miles (6 km) east of the Hudson River and ). Each sediment sample was removed from the grab sampler using individually prepared nonmagnetic, noncorrosive stainless-steel sediment spoons wrapped in aluminum foil and precleaned by washing in laboratory detergent and heating as described previously. Samples were placed into certified precleaned 4 ounce (118.4 ml) amber glass sampling jars (Environmental Sampling Supply [ESS (1) (Electronic Switching System) A large-scale computer from Lucent used to route telephone calls in a telephone company office. The 5ESS is a Class 5 central office switch, and the 4ESS is a Class 4 tandem office switch. ], Oakland, California “Oakland” redirects here. For other uses, see Oakland (disambiguation).
Oakland (IPA: /ˈoʊklənd/), founded in 1852, is the eighth-largest city in the U.S. ) according to a method validated for collection of both organic contaminant contaminant /con·tam·i·nant/ (kon-tam´in-int) something that causes contamination.
something that causes contamination. and metals sample collection (PSEP PSEP Pesticide Safety Education Program
PSEP Public Safety and Emergency Preparedness (Canada)
PSEP Polskie Stowarzyszenie Edukacji Prawnej
PSEP Professional Student Exchange Program
PSEP Puget Sound Estuary Program 1997). Sediment was stored and shipped to the laboratory as described for shellfish samples. Sediment blanks were included for a manual reading of temperature in shipping containers using a calibrated cal·i·brate
tr.v. cal·i·brat·ed, cal·i·brat·ing, cal·i·brates
1. To check, adjust, or determine by comparison with a standard (the graduations of a quantitative measuring instrument): thermometer thermometer, instrument for measuring temperature. Galileo and Sanctorius devised thermometers consisting essentially of a bulb with a tubular projection, the open end of which was immersed in a liquid. on arrival at the laboratory. Sediment samples were logged and tracked using the chain-of-custody system described for shellfish samples. Sediments from a Puget Sound, Washington site were also handled with and without the sediment spoons used in St. Louis Bay to verify that no artifactual ar·ti·fact also ar·te·fact
1. An object produced or shaped by human craft, especially a tool, weapon, or ornament of archaeological or historical interest.
2. metals were added to the samples that would affect the metals analysis. Sediment samples were taken independently from shellfish samples and labeled from 1 to 13 as shown on Figure 4.
Sediment samples for grain-size analysis and total volatile organic content were removed from the grab sampler while onboard the sampling vessel and placed in freezer bags with paper tracking labels to match exterior marking with waterproof felt-tip pens.
Sample Processing and Storage at Laboratory
Upon receipt at the laboratory, the recorded temperature data from each shipment container were downloaded and examined to ensure that temperature had not exceeded 4[degrees]C. Sediment samples were then frozen at -20[degrees]C in a non-self-defrosting freezer. Shellfish samples for dioxin and furan analysis were maintained between 0[degree] and 4[degrees]C until processing. Shellfish were either archived within their precleaned foil wraps, shucked and archived for metals analysis, or processed for dioxin analysis as follows.
All instruments and glassware for shellfish tissue processing for dioxin and furan analysis were precleaned and recleaned between individual sample processing by scrubbing thoroughly while immersed im·merse
tr.v. im·mersed, im·mers·ing, im·mers·es
1. To cover completely in a liquid; submerge.
2. To baptize by submerging in water.
3. in Alconox soapy water, then rinsed by immersion and agitation in laboratory 18-M[OMEGA] reagent-grade water, followed by unused rinse water poured over the instruments. The instruments or materials were then rapidly air dried on paper, rinsed with reagent reagent /re·a·gent/ (re-a´jent) a substance used to produce a chemical reaction so as to detect, measure, produce, etc., other substances.
n. grade 100% absolute methyl alcohol methyl alcohol: see methanol. (Certified Analytical Reagent, ACS (Asynchronous Communications Server) See network access server. , USP USP - unique sales point Reagent), rinsed with dichloromethane (Certified Analytical Reagent, ACS, USP Reagent), and allowed to air dry. A method blank consisting of rinse water was also collected and analyzed.
Each replicate sample of oysters contained between l0 and 20 individuals, except as noted in Table 3 (see Table 3 later in text). Prior to shucking, each oyster was scrubbed with fresh tap water in a laboratory sink and measured for shell "length" the linear distance between the dorsal dorsal /dor·sal/ (dor´s'l)
1. pertaining to the back or to any dorsum.
2. denoting a position more toward the back surface than some other object of reference; a synonym of posterior umbo umbo /um·bo/ (um´bo) pl. umbo´nes [L.]
1. a rounded elevation.
2. the slight projection at the center of the outer surface of the tympanic membrane.
n. tip and the ventral ventral /ven·tral/ (ven´tral)
1. pertaining to the abdomen or to any venter.
2. directed toward or situated on the belly surface; opposite of dorsal.
adj. shell margin (the morphologic shell height). The oysters were opened on a cleaned surface (Alconox scrubbed and rinsed). The oyster meats did not contact the work surface during preparation and only oysters that were previously tightly closed were selected for analysis. The soft tissues were placed in aluminum weigh "boats" that were cleaned by heating as previously described, to determine individual wet weights.
A section for histological his·tol·o·gy
n. pl. his·tol·o·gies
1. The anatomical study of the microscopic structure of animal and plant tissues.
2. The microscopic structure of tissue. examination was removed and placed in a histological cassette, followed by immersion into fixative fixative /fix·a·tive/ (fik´sit-iv) an agent used in preserving a histological or pathological specimen so as to maintain the normal structure of its constituent elements.
adj. . The remaining oyster meat was placed in a cleaned beaker beaker /beak·er/ (bek´er) a glass cup, usually with a lip for pouring, used by chemists and pharmacists.
a round laboratory vessel of various materials, usually with parallel sides and often with a pouring spout. and homogenized ho·mog·e·nize
v. ho·mog·e·nized, ho·mog·e·niz·ing, ho·mog·e·niz·es
1. To make homogeneous.
a. To reduce to particles and disperse throughout a fluid.
b. to a liquid slurry slurry,
n a thin mixture of insoluble material floating in liquid.
solids in suspension. Used as a method of feeding pigs—slurry is pumped through fixed lines and delivered to troughs by hoses equipped with gasoline pump fittings. form using a Pro Scientific (Oxford, Connecticut Oxford is a town located in western New Haven County, Connecticut, United States. The population was 9,821 at the 2000 Census. There are several areas in Oxford: Quaker Farms, Riverside and Oxford Center. ) 200-series homogenizer A laboratory equipment for the homogenization of various types of material, such as tissue, plant, food, soil, and many others. Many different models have been developed using various physical technologies for the disruption. with a 20-mm, saw-tooth generator. Depending on the amount of homogenized tissue available, one or two laboratory splits of the samples were then poured into the ESS-certified clean amber-glass jars and the net amount of tissue weighed. Samples were then stored at <4[degrees]C. Replicates not submitted to the laboratory within 2 days of processing were stored at -20[degrees]C.
Shellfish tissues for analytical chemistry analytical chemistry: see under chemistry. analysis were dispatched to the analytical laboratory packed in a solid cooler with labels and matching chain-of-custody forms. Ice packs and a small quantity of dry ice (0.5 -1.0 kg) were included within the sample containers. A blank sample for temperature recording upon receipt was included. Samples were sent by overnight courier for dioxin and PCB PCB: see polychlorinated biphenyl.
in full polychlorinated biphenyl
Any of a class of highly stable organic compounds prepared by the reaction of chlorine with biphenyl, a two-ring compound. analysis and hand delivered or sent by courier for metals analysis.
For metals analysis, shellfish were opened using nonmagnetic corrosion-resistant stainless-steel shucking knives, previously validated for handling bivalve bivalve, aquatic mollusk of the class Pelecypoda ("hatchet-foot") or Bivalvia, with a laterally compressed body and a shell consisting of two valves, or movable pieces, hinged by an elastic ligament. tissues used for trace-metals analyses (PSEP 1997; Stephensen et al. 1979). In addition, control oysters from a non-industrialized site were processed and analyzed in an identical manner to ensure that no artifactual metals were added to the samples.
Chemical Analysis of Shellfish Tissues and Marine Sediments marine sediment
Any deposit of insoluble material, primarily rock and soil particles, transported from land areas to the ocean by wind, ice, and rivers, as well as the remains of marine organisms, products of submarine volcanic activity, and chemical precipitates from
Dioxin and Furans
Frozen shellfish tissue homogenates and sediments were shipped as described above to Paradigm Analytical Laboratories (Wilmington, North Carolina For other places with the same name, see Wilmington (disambiguation).
Wilmington is a city in New Hanover County, North Carolina, United States. The population was estimated at 100,000 as of 2006; ) for analysis of sample content for 17 dioxin/furan congeners using the United States Environmental Protection Agency method SW846, method 8290 (USEPA 1997).
Polychlorinated Biphenyls polychlorinated biphenyls, (pol´ēklôr´nā´tid bīfē´n
The same sample set used for dioxin and furan analysis was analyzed for polychlorinated biphenyls (PCBs) by Paradigm Analytical Laboratories using the United States Environmental Protection Agency, method 1668A. (USEPA 1999).
An initial set of sediments and shellfish tissue samples were analyzed for total metals by the Battelle Marine Sciences Laboratory, Sequim, Washington using inductively-coupled, plasma-mass spectrometry spectrometry /spec·trom·e·try/ (spek-trom´e-tre) determination of the wavelengths or frequencies of the lines in a spectrum.
n. (ICP/MS ICP/MS Inductively Coupled Plasma/Mass Spectrometry (chemical analysis) ) as the analytical technique An analytical technique is a method that is used to determine the concentration of a chemical compound or chemical element. There are a wide variety of techniques used for analysis, from simple weighing (gravimetric) to titrations (titrimetric)to very advanced techniques using (except for mercury) using EPA EPA eicosapentaenoic acid.
n.pr See acid, eicosapentaenoic.
n. methods 1638 and 200.8 (USEPA 1996a & 1994, respectively), adapted for analysis of solid-sample digestates. Mercury was determined by cold-vapor atomic-absorption spectroscopy spectroscopy
Branch of analysis devoted to identifying elements and compounds and elucidating atomic and molecular structure by measuring the radiant energy absorbed or emitted by a substance at characteristic wavelengths of the electromagnetic spectrum (including gamma ray, (CVAA CVAA Cold Vapor Atomic Absorption
CVAA Consortium of Voluntary Adoption Agencies (UK)
CVAA Champlain Valley Agency on Aging, Inc. (Winooski, Vermont)
CVAA Central Valley Aviation Association ), based on EPA method 245.5 (USEPA 1991a). For these analyses, samples were freeze dried and homogenized using a ball mill prior to digestion with nitric acid nitric acid, chemical compound, HNO3, colorless, highly corrosive, poisonous liquid that gives off choking red or yellow fumes in moist air. It is miscible with water in all proportions. , hydrofluoric acids hydrofluoric acid /hy·dro·flu·o·ric ac·id/ (-floor´ik) a gaseous haloid acid, HF, extremely poisonous and corrosive.
n a compound consisting of hydrogen and flourine. and peroxide peroxide (pərŏk`sīd), chemical compound containing two oxygen atoms, each of which is bonded to the other and to a radical or some element other than oxygen; e.g. in a Teflon vessel, and heated in an oven at 130[degrees]C ([+ or -] 10[degrees]C) according to the laboratory standard operating procedure standard operating procedure Medtalk A technique, method or therapy performed 'by the book,' using a standard protocol meeting internally or externally defined criteria; a formal, written procedure that describes how specific lab operations are to be performed. and quality assurance/quality control documentation. This sample procedure was expected to yield total metals, including those that are bound as crystal silicates.
A second set of sediment and tissue samples were analyzed by the same ICP/MS method (EPA Method 200.8 [USEPA 1994], but were digested using EPA method 3050B (USEPA 1996b) which is not designed to be a total digest for most samples but will dissolve almost all elements that could become environmentally available and is thus comparable to the United States Environmental Protection Agency method used by Lytle and Lytle (1982). These samples were analyzed by Analytical Resources, Tukwila, Washington Tukwila (pronounced IPA: /tʌkˈwɪlə/) is a city in King County, Washington, about 6 miles south of Seattle. The population was 17,181 at the 2000 census. .
All shellfish were processed whole so that measured metals may have been either incorporated into the tissues or resident in the digestive tracts digestive tract
See alimentary canal.
The organs that perform digestion, or changing of food into a form that can be absorbed by the body. . This processing represents the potential ingestion ingestion /in·ges·tion/ (-chun) the taking of food, drugs, etc., into the body by mouth.
1. The act of taking food and drink into the body by the mouth.
2. exposure of the metals to human consumers because oysters are commonly eaten whole or the entire oyster body is used in preparing the oysters for consumption.
Grain Size-Analysis and Volatile-Organic Content of Sediments
Grain-size analysis and percent volatile solids were determined using methods ASTM D422-63 and EPA 160.4, respectively (ASTM 2003; USEPA 1979). These analyses were performed by Aquatic Research Inc. of Seattle, Washington This page is protected from moves until disputes have been resolved on the .
The reason for its protection is listed on the protection policy page. . Grain size and volatile organics were examined and compared with prior data from St. Louis Bay (Isphording 1985).
Dioxins and Furans
Dioxin and furan concentrations expressed as toxic equivalencies for shellfish collected in and near St. Louis Bay are shown in Table 1. Toxic equivalencies (TEQs) are expressed as WHO-TEQs (Vanden Berg et al. 1998) and I-TEQs (USEPA 1989), for comparison with a previous evaluation of oysters from southern Mississippi (Fiedler et al. 1997). The set of international toxic equivalency equivalency
the combining power of an electrolyte. See also equivalent. factors (I-TEFs) returns TEQ TEQ Toxicity Equivalent
TEQ Time Domain Equalizer
TEQ Teacher Education Quarterly
TEQ Terra Est Quaestuosa (web-based game, Spanish: Lland is Profitable)
TEQ The Evil Quakkers (gaming clan) values that are higher than those derived from using the World Health Organization TEFs due to differing TEF TEF Tracheoesophageal fistula, see there values for three congeners. In addition, the data available from the Fiedler et al. (1997) paper are based on using one half the limit of quantification value (1/2 LOQ LOQ Limit of Quantitation
LOQ Limit Of Quantification
LOQ Loquitur (Latin: speaks)
LOQ Level of Quantification
LOQ List Of Questions
LOQ Laugh Out Quiet
LOQ Leadership Opinion Questionaire ) for nondetects. The LOQ is defined as 10 times the standard deviation In statistics, the average amount a number varies from the average number in a series of numbers.
(statistics) standard deviation - (SD) A measure of the range of values in a set of numbers. of the average of a series of blank measurements and likely overstates the contribution of non-detects (Jensen & Bolgar 2001). Therefore, our comparison, from data derived using one half detection limit values for non-detects, to the Fiedler et al. (1997) values is a conservative estimate of the difference between the two data sets, because the 1997 values may have been lower than reported if the raw data had been presented as we present our raw data. Congeners measured are shown in Table 2. The shellfish tissue values for data generated in this study were converted to I-TEQs and WHO-TEQs with appropriate TEFs using the EPA-referenced method (USEPA 1989) advising that the common conservative approach for non-detected congeners is to set their value at one-half of the detection limit (ND = 1/2).
In addition, the I-TEQs were expressed adjusted for lipid so that they could be compared with the prior study by Fiedler et al. (1997) of dioxins and furans in oysters collected as part of a market-basket assessment of food products from southern Mississippi. Only the specific congener analytes common to both studies were used in the comparison. Table 1 shows that the WHO-TEQ values (ND = 1/2) for the 17 congeners of dioxins and furans in oysters (total tissue basis) from within and near St. Louis Bay ranged from 0.312 pg/g to 0.463 pg/g wet tissue weight with an average value of 0.378 pg/g. Rangia clams collected from shellfish collection track 1 had a higher WHO-TEQ of 0.581 pg/gm. Oysters from inside the bay only (collection tracks 2 to 8) had an average WHO-TEQ of 0.398 pg/g and oysters collected from open harvest sites between the highway and railroad bridges at the mouth of the bay and from sites outside the bay had an average WHO-TEQ of 0.343 pg/g. The shellfish collection track with the highest WHO-TEQ inside the bay was collection track-7B, located in the midbay region, and the site with the highest TEQ outside the bay was shellfish collection track-17 (located ~7 km southwest of the center of the bay mouth and between 0.67 and 1.48 km offshore).
When the I-TEQ values for shellfish tissues were lipid adjusted (i.e., expressed as a concentration in the lipid fraction only) for comparison with those reported by Fiedler et al. (1997), the I-TEQ values for the clam sample was 165.5 pg/g lipid, the average value for oysters within the bay was 98.2 pg/g lipid, and the average value for oysters south of the highway bridge and outside the bay was 58.8 pg/g lipid. The two highest values for lipid adjusted I-TEQ were shellfish collection track 2 (152.4 pg/g lipid), located just south of the refinery outfall in St. Louis Bay and shellfish collection track 3 (247.9 pg/g lipid) also located nearby the outfall and southeast of Grassy Point (Fig. 2).
Total dioxins and furans and TEQ values for sediments are shown in Table 2. The two highest WHO-TEQ values in St. Louis Bay (11.41 and 11.78 pg/g sediment dry-weight basis) were located at sediment stations 2 and 3, respectively, which were the stations closest to the titanium dioxide refinery effluent outfall point, labeled as a sewer on National Oceanic and Atmospheric Administration (NOAA) Nautical Charts 11371 and 11372A and in Figure 2 and Figure 4. These two stations were also the only in-bay stations with detectable levels of 2,3,7,8-TCDD, the most toxic of the dioxin congeners. Sediment station 2 is located approximately 260 m south of the discharge of the refinery outfall pipe, and sediment station 3 is located approximately 1.6 km to the south-southwest of the outfall discharge (Fig. 4). The highest value outside the bay (15.33 pg/g) was located at sediment station 12 between Henderson Point and Square Handkerchief Shoal, which was also the only out-of-bay station with a detectable level of 2,3,7,8-TCDD. The average sediment WHO-TEQ value inside the bay (sediment stations 1 to 8) was 8.57 pg/g, and the average WHO-TEQ value for the stations outside of the bay (sediment stations 9 to 13) was 7.92 pg/g. Due to variation in half-life of constituent congeners (Sinkkonen & Paasivirta 2000) and lack of source test data, we did not attempt a quantitative comparison of congeners from the various stations.
Sediment Grain Size, Volatile Solids, and Association with Dioxin Concentrations
The sediments in this study were largely sandy-silts (median diameter, 82 [micro]m). Sediment grain size did not correlate well with total dioxin, but total volatile solids, consisting of all organic material and carbonates, showed a higher inverse correlation coefficient Correlation Coefficient
A measure that determines the degree to which two variable's movements are associated.
The correlation coefficient is calculated as: for sites inside the bay (r = 0.86; n = 8) than for sites outside the bay (r = 0.73; n = 5).
Total Dioxin Load Estimate for St. Louis Bay Sediments
The total load of the measured 17 congeners of dioxins and furans in St. Louis Bay sediments was estimated by using the average concentration of all congeners at each sediment site located within the bay, north of US Highway 90. The surface area of the bay was estimated at 40.9 [km.sup.2] and the area of the bay and surrounding marshlands was estimated at 54.1 [km.sup.2]. However, a figure of only 75% of the bay surface area was used as a conservative factor in estimation of a minimum burden number. The marshlands surrounding the bay and comprising an additional 13.2 [km.sup.2] were not included in the minimum estimate calculation, although they may be periodically inundated in·un·date
tr.v. in·un·dat·ed, in·un·dat·ing, in·un·dates
1. To cover with water, especially floodwaters.
2. with seawater at high tide. The maximum estimate calculation included the full area of the bay and the surrounding marshlands or an area 76% greater than the minimum estimated area (consisting of 75% of the bay surface area). Therefore the minimum calculation is conservative.
To estimate the total burden of the 17 measured dioxin and furan congeners in St. Louis Bay, the sediment concentration per gram was calculated by converting the dry weight concentrations of dioxins and furans to wet weight concentrations using an average moisture content of sediments of 66% (determined in the analytical preparation of sediments) and the empirically measured average of 1.35 g of wet sediment per cubic centimeter cu·bic centimeter
Abbr. cc A unit of volume equal to one thousandth (10-3) of a liter or to one milliliter. . Because sediment samples were taken and mixed from the top 4 cm of sediment, the burden was calculated for the top 4 cm of sediment only. This calculation yielded a total burden of measured dioxins and furans in the sediments of 3.72 kg for 75% of the area of St. Louis Bay, to a depth of 4 cm, assuming that the bay bottom was a planar A technique developed by Fairchild Instruments that creates transistor sublayers by forcing chemicals under pressure into exposed areas. Planar superseded the mesa process and was a major step toward creating the chip. surface. If the entire area of the bay as well as the marshlands were to be included, this estimate would increase by 76% to 6.56 kg. In addition, dioxins and furans may be present at sediment depths >4 cm.
The WHO-TEQs for PCBs (ND = 1/2) for sediment samples ranged from 0.113-0.225 pg/g on a dry-weight basis for all sample sites. The WHO-TEQs for PCBs (ND = 1/2) for oyster samples ranged from 0.108-0.125 pg/g on a wet-weight basis.
Trace Metals--Shellfish Tissues
Trace-metal values for shellfish, derived using the extraction method for bioavailable metals (second analytical set), inside St. Louis Bay and in locations near the mouth of the bay are shown in Table 3, referenced to sample locations shown in Figures 2 and 3. For edible oysters inside the bay, these values show large increases from the 1978 study in arsenic arsenic (är`sənĭk), a semimetallic chemical element; symbol As; at. no. 33; at. wt. 74.9216; m.p. 817°C; (at 28 atmospheres pressure); sublimation point 613°C;; sp. gr. (stable form) 5.73; valence −3, 0, +3, or +5. (percent value of 404% compared with 1978), chromium (percent value of at least 1,167% compared with 1978), and nickel (percent value of at least 467% compared with 1978). Selenium selenium (səlē`nēəm), nonmetallic chemical element; symbol Se; at. no. 34; at. wt. 78.96; m.p. 217°C;; b.p. about 685°C;; sp. gr. 4.81 at 20°C;; valence −2, +4, or +6. increased 48% and the other metals showed decreases from the 1978 study. In Rangia clams, also evaluated in the 1978 study, there were increases in the content of all metals measured, which registered above detection limits (Table 3) and were measured in the 1978 and 2004 studies, with the exception of zinc. There was only a minor increase in mercury in clams. The increased concentrations in Rangia clams were greater than that for oysters with the largest increases in arsenic (percent value of 1,920% compared with 1978) and nickel (percent value of at least 1,225% compared with 1978). A value for chromium in Rangia clams was not reported in the 1978 study. Hooked mussels, considered a non-edible species, showed the lowest concentrations of metals. Based on this data set, the highest concentrations of chromium and nickel in any of the shellfish were from oysters taken at shellfish dredge site 16 (Fig. 3), an area open to oyster harvest, located about 1.7 km south of Henderson Point, which forms the eastern aspect of the mouth of St. Louis Bay.
The first data set (i.e., metals obtained by total digestion) yielded similar but somewhat higher values for metals, as expected. Because this could have been due to a contribution of mineral-bound and nonbioavailable metals and a small artifactual increase during processing (measured at 1 [micro]g/g for Cr and about 0.5 [micro]g/g for Ni, for tissue samples only) of the samples for dioxin analysis (not conducted on or applicable to the second sample set), we have excluded this data set from comparative evaluation with the 1978 data. However, it is included in summary form (Table 4) because it confirms the high values of metals in oysters from an open harvest area and emphasizes the need for public health agencies to consider these data in regard to the suitability of such oysters for human consumption and, at a minimum, to provide public notice of the potential for negative health effects to specific groups of the population. Examination of metals content from shellfish from data set 1 shows that values as high as 12.3 [micro]g/g for chromium and 7.54 [micro]g/g for nickel were found in edible oysters from open harvest shellfish collection site 15. Even allowing for a reduction in up to 1 [micro]g/g in these values, based on control studies applying only to this data set, these are still high values with regard to human consumption, as will be discussed in following text. Using the first and second data sets for metals, respectively, the chromium content of oysters in Mississippi Sound, adjacent to St. Louis Bay showed percent values of at least 11,300% and 7,700% compared with the 1978 values (below detection limit) reported for in Bay oysters in 1978. However, in utilizing the US Food and Drug Administration estimated safe and adequate daily dietary intake for specific metals (USFDA USFDA United States Food & Drug Administration 1993a, b, c), we used only metals data set 2, designed to analyze for bioavailable metals.
The 1978 values for trace metals in sediments from St. Louis Bay were from sampling and analysis reported by Lytle and Lytle (1982) prior to the construction and operation of the titanium dioxide refinery. Based on comparison of the 1978 data with our values for sediment station 2, chromium, beryllium beryllium (bərĭl`ēəm) [from beryl ], metallic chemical element; symbol Be; at. no. 4; at. wt. 9.01218; m.p. about 1,278°C;; b.p. 2,970°C; (estimated); sp. gr. 1.85 at 20°C;; valence +2. , nickel, arsenic, and lead increased (listed in descending order of magnitude A change in quantity or volume as measured by the decimal point. For example, from tens to hundreds is one order of magnitude. Tens to thousands is two orders of magnitude; tens to millions is three orders of magnitude, etc. ) in St. Louis Bay sediments between 1978 and 2004 (Table 5). The percent value for copper in 2004 was 90% of that in 1978 and the similar value for zinc in 2004 was 80% of that in 1978. Cadmium cadmium (kăd`mēəm) [from cadmia, Lat. for calamine, with which cadmium is found associated], metallic chemical element; symbol Cd; at. no. 48; at. wt. 112.41; m.p. 321°C;; b.p. 765°C;; sp. gr. 8. , antimony antimony (ăn`tĭmō'nē) [Lat. antimoneum], semimetallic chemical element; symbol Sb [Lat. stibium,=a mark]; at. no. 51; at. wt. 121.75; m.p. 630.74°C;; b.p. 1,750°C;; sp. gr. (metallic form) 6. , and selenium were below detection limits in the 1978 study and this data set from 2004. Mercury was detected at 0.107 [micro]g/g in 1978 and found to be 0.095 [micro]g/g in 2004. Although there were no 1978 data to compare sites outside of the bay with the 2004 values, chromium and nickel values from sites outside but near St. Louis Bay were higher in 2004 than the values reported for these metals inside the bay in 1978.
The increase noted in some of these metals is undoubtedly an anthropogenic effect. Particle size Particle size, also called grain size, refers to the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. analyses carried out by Isphording (1985) in St. Louis Bay versus those in the present investigation clearly show a coarsening trend for bay sediments over the past 20 y. The 1985 sediments were largely silty-clays (median diameter, 14.1 [micro]m) whereas those at present are chiefly sandy-silts (median diameter, 57 [micro]m, in-bay). As such, the expected trend would be for lower natural levels of heavy metals to be found in the sediments. Sorption sorption /sorp·tion/ (sorp´shun) the process or state of being sorbed; absorption or adsorption.
Adsorption or absorption. of heavy metals in sediments is closely related to grain size (see Cordi et al. 2003) because sand-sized sediment (i.e., >62 [micro]m) and medium to coarse silt-size sediment (those 10-62 [micro]m) will consist almost entirely of the mineral quartz (Si[O.sub.2]). Quartz shows almost no tendency to adsorb adsorb /ad·sorb/ (ad-sorb´) to attract and retain other material on the surface; to conduct the process of adsorption.
To take up by adsorption. contaminants because it closely approaches its stoichiometric stoi·chi·om·e·try
1. Calculation of the quantities of reactants and products in a chemical reaction.
2. The quantitative relationship between reactants and products in a chemical reaction. composition under natural conditions and has few site vacancies that produce positions where ions can "attach." The clay-sized sediments (by definition, those <4 [micro]m in size) in St. Louis Bay, in contrast, consist largely of the Smectite Smec´tite
n. 1. (Min.) A hydrous silicate of alumina, of a greenish color, which, in certain states of humidity, appears transparent and almost gelatinous. Group clay mineral clay mineral
Any of a group of important hydrous aluminum silicates with a layered structure and very small (less than 0.005 mm or microscopic) particle size. They are usually the products of weathering. montmorillonite Montmorillonite is a very soft phyllosilicate mineral that typically forms in microscopic crystals, forming a clay. It is named after Montmorillon in France. Montmorillonite, a member of the smectite family, is a 2:1 clay, meaning that it has 2 tetrahedral sheets sandwiching a , (Ca,Na)[(Al,Mg,Fe).sub.4][[(Si,A1).sub.8][O.sub.20]][(OH).sub.4] * n[H.sub.2]O). This mineral is characterized by numerous Schottky-Wagner (missing ion) defects that render the clay micelle micelle (mīsel´),
n a space formed by the brush structure of fibrils in colloidal gels. The spaces are occupied by water in hydrocolloid impressions. surfaces "charged." Hence the mineral can abundantly adsorb organic and inorganic impurities and contaminants. Montmorillonite clays also possess very high cation exchange capacities In soil science, cation exchange capacity (CEC) is the capacity of a soil for ion exchange of positively charged ions between the soil and the soil solution. A positively-charged ion, which has fewer electrons than protons, is known as a cation due to its attraction to cathodes. (100-300 milliequivalents/liter). This property, similarly, renders them capable of adsorbing a wide variety of metals and organo-metallic species. Not unexpectedly, then, when the median diameters of the 13 samples collected in this study were compared with the total dioxin and furan levels from Table 2, an inverse correlation of r = 0.70 was obtained. A less strong, but statistically significant inverse correlation (r = 0.54) was also obtained when dioxin and furan levels from Table 2 were compared with the percentage of sediments in each sample in the 3- to 12-micron range. This size fraction is important because it includes the size range of particles that are ingested in·gest
tr.v. in·gest·ed, in·gest·ing, in·gests
1. To take into the body by the mouth for digestion or absorption. See Synonyms at eat.
2. by filter feeding oysters. Given that the sediments demonstrably de·mon·stra·ble
1. Capable of being demonstrated or proved: demonstrable truths.
2. Obvious or apparent: demonstrable lies. contain elevated levels of both dioxins and furans, it is not therefore surprising that St. Louis Bay shellfish exhibit heightened levels of both of these compounds.
In addition to contaminants associated with the clay minerals Clay minerals are hydrous aluminium phyllosilicates, sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths and other cations. Clays have structures similar to the micas and therefore form flat hexagonal sheets. , the fine silt and clay fraction (particles <10 [micro]m) also contains significant quantities of iron and manganese manganese (măng`gənēs, măn`–) [Lat.,=magnet], metallic chemical element; symbol Mn; at. no. 25; at. wt. 54.938; m.p. about 1,244°C;; b.p. about 1,962°C;; sp. gr. 7.2 to 7. oxide and oxyhydroxide compounds. These, similarly, are marked by extensive substitution of a wide variety of metal ions for both iron and manganese. Hence, a decrease in the quantity of fine silt and clay-size sediments over the 20-y period would be expected to produce a decrease in metal levels and other contaminants. The increase observed in this investigation must therefore be the result of "loading" of the reduced quantities of fine silt and clay due to high levels of contaminant influx.
Toxic Equivalents of Dioxins, Furans, and PCBs in Shellfish
The WHO-TEQ values based on a whole-shellfish soft tissue wet-weight basis averaged 0.392 pg/g for oysters and was 0.581 pg/g for the single sample of Rangia clams. While there is no defined action level in the United States, the US Food and Drug Administration advises that "Since there are no tolerances or other administrative levels for dioxins in food or feed, the appearance of these compounds in a food or feed supply is of gravest concern" (USFDA 2000). The European Union European Union (EU), name given since the ratification (Nov., 1993) of the Treaty of European Union, or Maastricht Treaty, to the
European Community (EU) has defined action levels of between 0.5 and 4.5 pg/g (based on WHO-TEQ) for dioxins, furans, and dioxin-like biphenyls in various seafoods related products (EC 2002). Because these action levels include dioxin-like biphenyls, and in setting the action level, studies showed that only 25% to 50% of the total dioxin equivalents came from dioxins and furans, the effective EU action level for dioxins and furans separately is closer to 1.0-2.0 pg/g. In 1981, The US Food and Drug Administration recommended a 25-pg/g maximum dioxin level to address contamination of fish in the Great Lakes Great Lakes, group of five freshwater lakes, central North America, creating a natural border between the United States and Canada and forming the largest body of freshwater in the world, with a combined surface area of c.95,000 sq mi (246,050 sq km). . Subsequently, in 1997, the USFDA (1997) issued prohibition of the sale of catfish catfish, common name applied to members of the freshwater fish families constituting the suborder Nematognathi. The catfish is related to the sucker and the minnow, and like them has a complex set of bones forming a sensitive hearing apparatus. containing more than 1 pg/g dioxin, but subsequently rescinded this restriction (USFDA 1997). We compared the values for oyster dioxin and furan TEQs from this study with those reported previously by Fiedler et al. (1997). Only the congeners reported by Fiedler et al. (1997) that were also evaluated in this study were used, and I-TEQ (ND = 1/2) values for nondetects in our data were used. The Fiedler values could be an overestimate o·ver·es·ti·mate
tr.v. o·ver·es·ti·mat·ed, o·ver·es·ti·mat·ing, o·ver·es·ti·mates
1. To estimate too highly.
2. To esteem too greatly. of the actual toxic equivalents present because they use 1/2 LOD Lod (lōd), city (1994 pop. 51,200), central Israel. It is also known as Lydda. Its manufactures include paper products, chemicals, oil products, electronic equipment, processed food, and cigarettes. values for nondetects. Thus, our comparison to their values of the increase in dioxins and furans includes a conservative estimation factor, due to the necessity of using their values based on 1/2 LOD. The Fiedler et al. (1997) study was a market-basket survey of various food stuffs, including oysters, from grocery stores and seafood markets in southern Mississippi, although the source location of the oysters was not specified. Fiedler et al. (1997) report lipid-adjusted values (i.e., they expressed the total dioxin and furan analytes as a concentration of the lipid portion only of the animal) because, as they noted, dioxins and furans accumulate in the lipid compartment of animal tissues.
Using this lipid-adjusted means of expression, these authors reported values of from 21.0-31.4 pg/g I-TEQ for the oysters. Using the same method of calculation (but using 1/2 detection limit values for nondetects), we found lipid-adjusted I-TEQ concentrations ranging from 54.2-247.9 pg/g for oysters in St. Louis Bay, 165.5 pg/g for Rangia clams in St. Louis Bay and concentrations ranging from 36.6-79.1 pg/g for oysters from open harvest areas south of and adjacent to St. Louis Bay. Thus, the comparison of lipid adjusted values from the 1997 paper to those of the current study indicates a doubling to near an order of magnitude greater values for dioxin and furan TEQs for St. Louis Bay oysters versus those from southern Mississippi in 1997. In most circumstances, this would be surprising because a number of studies have indicated that dioxin concentrations in the environment, in food stuffs, as well as human exposure levels, have been decreasing for several decades (e.g., USEPA 1991b; Smith et al. 1995, Pearson et al. 1995, Pinsky & Lorber 1998, Winters et al. 1998). Dioxin and furan concentrations in St. Louis Bay in 2004 were about 2.6 to 7.9 times higher than the low and high values, respectively, reported in the 1997 study. Dioxin and furan values outside of St. Louis Bay in 2004, in open harvest areas, are about 1.8 to 2.5 times higher than the low and high values, respectively, reported in 1997. The actual increase may be higher due to the use of 1/2 LOQ values by Fiedler et al. in 1997. Our average value for total dioxin and furan TEQs is lower than a national average (0.448 ppt ppt
1. parts per thousand
2. parts per trillion ) reported by Jensen and Bolgar (2001) for mollusks (using 1/2 detection limit values for nondetects). However, that study did not specify the collection sites or mix of species used in the reported number. The more significant comparison is the rise in values of contaminants in oysters collected in southern Mississippi between 1997 and 2004, during a time period when dioxins were generally decreasing in the environment.
It should be noted that the female oysters collected for this study were not in a condition of peak reproductive development, when lipid levels would be expected to be higher. At that time, lipid levels can range from 10% to 15% as a proportion of total body weight, even after peak reproductive conditioning (Barber et al. 1988a, Barber et al. 1988b). Rather, the average lipid levels of oysters from all sites in our study were low, only 0.59%. Assuming an equal proportion of males and females, this indicates that the lipid content could be greater by a factor of 8.5-12.7, assuming no lipid increase in reproductively mature males. This indicates that at certain times of the season, the dioxin content of oyster samples could similarly increase by a factor of 8.5-12.7 to levels that would be of public health concern, although the rate of accumulation is unknown and thus the maximum potential accumulation is also unknown. However, the high potential accumulation rates would be of particular concern for sites outside of, but near, St. Louis Bay that are open for harvest.
The even higher TEQ values of sediments, compared with shellfish TEQ values, and potential new dioxins and furans added to the marine environment, provide the source for such additional accumulation of these carcinogens Carcinogens
Substances in the environment that cause cancer, presumably by inducing mutations, with prolonged exposure.
Mentioned in: Colon Cancer, Rectal Cancer . A paper published in 1996 (Comber comb·er
1. One, such as a machine or a worker, that combs something, such as wool.
2. A long wave that has reached its peak or broken into foam; a breaker. et al. 1996) indicated that relatively high values of dioxins and furans were acceptable in freshwater sediments. However, these guidelines were based on toxicity of the sediments to trout eggs and fish and did not address toxicity to organisms residing in marine sediments. The risk posed by sediment dioxins and furans to mollusks residing in or near the sediments is a function of multiple factors including sediment resuspension Noun 1. resuspension - a renewed suspension of insoluble particles after they have been precipitated
suspension - a mixture in which fine particles are suspended in a fluid where they are supported by buoyancy , congener half-life, sediment transport, addition rate of new congeners, and removal rate of dioxins by natural processes.
Calculation of TEQ values for PCBs in shellfish and sediments showed that they were below recognized levels of concern.
Estimation of Total Dioxins and Furans in Bay Sediments
As noted in the Results section, we conservatively estimated the total load of the measured 17 congeners of dioxins and furans in sediments of St. Louis Bay at 3.72 kg. This estimated value would increase by 76% to 6.56 kg if marshlands and the total bay area were included.
Visual inspection of the data (Table 2) suggests similarity between the dioxin and furan content of all the sites with relatively high proportions of OCDD OCDD Office for Citizens with Developmental Disabilities (Louisiana State Department of Health and Hospitals)
OCDD Orthonormal Code Diversity Detection and 1,2,3,4,6,7,8-HpCDD; 1,2,3,7,8,9 HxCDD; and 1,2,3,6,7,8 HxCDD in all samples, both inside and outside St. Louis Bay. However, we judged that a numerical analysis numerical analysis
Branch of applied mathematics that studies methods for solving complicated equations using arithmetic operations, often so complex that they require a computer, to approximate the processes of analysis (i.e., calculus). of the similarity of congener composition between sites in this study and between our values and the reported discharge values from the titanium dioxide refinery (USEPA 2003) would not be meaningful because the residence time of the dioxin and furan components at each site is unknown, and the half-life of congeners in sediments varies markedly (Sinkkonen & Paasivirta 2000).
Heavy Metals in Shellfish and Sediments of St. Louis Bay and Adjacent Marine Waters
Our study found a marked increase in the bioavailable heavy metals, namely chromium, nickel, and arsenic in oysters in St. Louis Bay and adjacent waters of Mississippi Sound compared with the prior survey. Chromium and nickel were not detected in oysters in St. Louis Bay in 1978 and arsenic was detected at about 25% of the 2004 concentration in 1978 oyster samples. Evaluation of Rangia clams shows that the burden of all metals measured above detection limits, except zinc, have increased in shellfish in St. Louis Bay since 1978, with the greatest increases in arsenic and nickel.
Metals appear to have also increased in sediments in St. Louis Bay and adjacent marine waters. However, because the large increases in chromium and nickel accumulation in shellfish appear spatially linked to the titanium dioxide refinery, which produces soluble metal chlorides, the discharge of such compounds may, in large part, be carried outside of St. Louis Bay where precipitation and dispersion in the higher salinity waters of Mississippi Sound would occur. Thus, sediment data are of limited value in estimating the contamination of St. Louis Bay waters by metals from the titanium dioxide refinery because the refinery process that utilizes the chloride-ilmenite process (USEPA 2001) results in acidified acidified /acid·i·fied/ (ah-sid´i-fid) having been made acid. soluble metal chlorides (MDEQ MDEQ Michigan Department of Environmental Quality
MDEQ Mississippi Department of Environmental Quality
MDEQ Montana Department of Environmental Quality
MDEQ Massachusetts Department of Environmental Quality 2003) which, assuming these are the most likely source of contaminants, would be expected to be largely flushed out of St. Louis Bay as dissolved matter, where they would tend to precipitate precipitate /pre·cip·i·tate/ (-sip´i-tat)
1. to cause settling in solid particles of substance in solution.
2. a deposit of solid particles settled out of a solution.
3. occurring with undue rapidity. and be dispersed in the more saline waters Saline water is a general term for water that contains a significant concentration of dissolved salts (NaCl). The concentration is usually expressed in parts per million (ppm) of salt. of Mississippi Sound. It is also presumed that this process produces primarily chromium-III, rather than the more highly toxic highly toxic Occupational medicine adjective Referring to a chemical that 1. Has a median lethal dose–LD50 of ≤ 50 mg/kg when administered orally to 200-300 g albino rats 2. and carcinogenic carcinogenic
having a capacity for carcinogenesis. chromium-VI.
Metal Content of Edible Oysters and Recommended Safe Consumption Levels
Table 6 shows the estimated safe and adequate daily dietary intake (ESADDI ESADDI Estimated Safe and Adequate Dail Dietary Intake ) for chromium-III and nickel and compares these to the content of the metals in oysters from St. Louis Bay and adjacent waters of Mississippi Sound in this 2004 study (USFDA 1993b, USFDA 1993c). Although these values are stated to represent only the historical record, according to the US Food and Drug Administration, they have not been replaced by new USFDA recommendations or guidelines and have been widely adopted as the standard for ESADDI (Beers & Berkow 2004; PDR PDR
A trademark for Physicians' Desk Reference, a group of reference books containing drug listings, especially one for prescription drugs.
PDR 2004). Using these ESADDI values indicates that the oysters, which previously had no detectable chromium and nickel in 1978 and about 25% of the 2004 value of arsenic, are now sufficiently burdened with these metals that less than one oyster per day can be consumed from open harvest areas near St. Louis Bay without exceeding the ESADDI levels for chromium-III and nickel for hypersensitive individuals. The oysters inside St. Louis Bay, currently a closed area due to bacterial contamination, have lower concentrations of these metals but are markedly elevated compared to 1978.
The increases in chromium and nickel are the most significant in terms of ESADDI of these metals (Table 6). Based on these values, and assuming that oysters are the only source of dietary chromium, for example, the consumption of oysters from inside St. Louis Bay should not exceed about 3 1/2 per day. However, oyster harvest from the bay is not permitted because of bacterial contamination. More significantly, based on average chromium levels (assumed to be chromium-III) in oysters from adjacent waters outside the bay, such oysters should not be consumed at a rate of more than two medium oysters per day. At the site with the highest chromium level, medium-sized oysters should not be consumed at a rate of more than 0.8 oysters per day to not exceed the ESADDI. For individuals hypersensitive to nickel (estimated to be about 10% of females and 2% of males in a European population, for example [Flyvholm et al. 1984]) and who are thus susceptible to nickel eczema eczema (ĕk`səmə), acute or chronic skin disease characterized by redness, itching, serum-filled blisters, crusting, and scaling. , oysters with average nickel concentrations outside the bay should not be consumed at a rate of more than 0.5 oyster per day or at a rate of more than 0.2 oyster per day from sites with the highest recorded nickel content, based on the ESADDI. Based on the USFDA (1993a) advisory, arsenic levels are probably not of concern, although elevated over those of 1978, because 90% or greater of the arsenic found in shellfish is usually in organic form, rather than the toxic inorganic form. The analysis performed in this study did not discriminate between organic and inorganic arsenic. All of the above computations of the ESADDI of these metals assume that oysters are the sole dietary source of the metal.
The relatively high chromium content in the oysters in this study is surprising due to the discrimination of Eastern oysters The eastern oyster, Crassostrea virginica, also known as the American oyster, Atlantic oyster, or the Virginia oyster, is a species of oyster that is native to the eastern seaboard of North America. against accumulation of chromium in relation to other metals (Huanxin et al. 2000). These authors found that chromium concentrations were lowest in relation to sediment concentrations when compared with several other metals. Our study established the content of chromium in whole oyster meats, some of which may have been in the digestive tract, associated with food particles, including those that would have complexed with soluble chromium compounds. However, as indicated previously, the total content of bioavailable chromium is important due to the consumption of whole oysters as a food product.
Transport of Contaminants out of St. Louis Bay
Studies of St. Louis Bay and the adjacent waters of Mississippi Sound indicate that a salinity gradient exists across the mouth of St. Louis Bay, and that the low salinity outflow of the bay consistently occurs on the western side and continues to follow the shoreline westward for some distance (Eleuterius 1976). This circulation pattern helps explain the higher than average TEQs for dioxins in shellfish from sample tract number 17 and the relatively high value for total dioxins and furans at sediment site 13 as well as the lower values at sediment sites 9 and 10. However, considerable mixing occurs outside the mouth of St. Louis Bay and depends on weather and sea state conditions. Weather fronts from autumn through spring may push waters south of the bay either northeastward or southeasterly south·east·er·ly
1. Situated toward the southeast.
2. Coming or being from the southeast.
south·east depending on the wind direction. Such conditions could account for mixing and higher accumulation of contaminants such as total dioxins and furans at sediment station 12 and chromium in oysters in shellfish dredge tract 16. According to a circulation model of the bay (Cobb & Blain blain
A skin swelling or sore; a blister; a blotch. 2002), there can be a net west to east flow south of the mouth of St. Louis Bay resulting from ebb tide ebb tide
The receding or outgoing tide; the period between high water and the succeeding low water.
The period between high tide and low tide during which water flows away from the shore. flows and wave induced currents In`duced´ cur´rent
1. (Elec.) A current due to variation in the magnetic field surrounding its conductor. . Chromium, presumed to be released in soluble form into St. Louis Bay, would be likely to accumulate in oysters near the bay than in sediments because soluble chromium compounds would be expected to precipitate or complex with fine particles Fine particles are an air pollutant mainly produced by cars running on diesel. Other sources are the combustion of fossil fuels in power plants and various industrial processes. that are ingested by filter-feeding oysters.
Other factors acting to control distribution of contaminants observed in the fauna and sediments again involved both the grain-size distribution of sediments at a given site and mineral speciation speciation
Formation of new and distinct species, whereby a single evolutionary line splits into two or more genetically independent ones. One of the fundamental processes of evolution, speciation may occur in many ways. at the site. Higher levels of furans and dioxin are found where the content of fine silt and clay-size sediment is greatest. Clay minerals, however, are more likely to settle out where a change to a higher salinity is encountered. This causes the clay particles (micelles) to flocculate floc·cu·late
v. floc·cu·lat·ed, floc·cu·lat·ing, floc·cu·lates
1. To cause (soil) to form lumps or masses.
2. To cause (clouds) to form fluffy masses.
v.intr. and thus "clump" to form hydraulically larger sized sediment, which settles more quickly to the bottom. This is particularly apparent at sites 7, 8, 12, and 13, each of which contains approximately 20% or more of clay-size particles. Each of these sample locations is also the site of elevated congeners of dioxin and furans that are similar, or exceed levels found immediately offshore from the titanium-dioxide refinery.
Sources of Contamination
Potential sources for dioxin, chromium, and nickel contamination of St. Louis Bay and the nearby waters of Mississippi Sound were reviewed using the United States Environmental Protection Agency Toxic Release Inventory (TRI) Program's TRI Explorer (www.epa.gov/enviro/html/tris/) and the EPA Envirofacts Warehouse (http://www.epa.gov/enviro/index.html). The Toxic Release Inventory Program makes data available to the public. However, it is important to recognize that the program does not mandate monitoring, and some of the TRI data are based on monitoring protocols whereas other data are derived by using various estimation techniques. Because facility activities and patterns of disposal or other releases can vary dramatically from one year to the next multiyear data were evaluated, as available.
Toxic release data from facilities in Hancock and Harrison Counties Harrison County is the name of eight counties in the United States:
EPA Toxic Release Inventory records report release of dioxins only for the years 2000 to 2003, due to regulatory changes effective in the year 2000, when certain new persistent bioaccumulative toxic (PBT PBT Provider Backbone Transport (networking technology adding determinism to ethernet)
PBT Polybutylene Terephthalate
PBT Profit Before Tax
PBT Paper Based Test (education) ) chemicals were added to the TRI list of reportable chemicals.
In reviewing the EPA TRI records, no significant sources of dioxin contamination were found in the St. Louis Bay watershed, other than the titanium dioxide refinery on the northern shore of St. Louis Bay. In fact, TRI records show no release of dioxin or dioxin-like compounds reported in Hancock County Hancock County is the name of ten counties in the United States. All are named for John Hancock who was a leader in the American Revolution. The counties are:
Mississippi Power has 1,253 employees and serves most of the cities, towns, and communities within the 23 counties of southeast Mississippi. Company Jack Watson Notable people named Jack Watson include:
the seven decades of Eleanor Pargiter’s life. [Br. Lit.: Benét, 1109]
See : Time titanium dioxide refinery reported release of 19,493.17 g, 18,201.2 g, and 20,078.11 g. The total amount of dioxins released on-site for the years 2000 to 2003 for the Mississippi Power Company Jack Watson Power Plant was 1.39 g, compared with 72,817.41 g disposed of or released on-site by the titanium dioxide refinery for the same time period. Dioxin release by facilities in the other counties in the Mississippi Coastal Watershed was examined also. In 2002, a representative year, the total amount of dioxin and dioxin-like compounds reported released was as follows: Jackson County Jackson County is the name of 23 counties and one parish in the United States:
River, central Mississippi, U. County, 1.2 g; and Stone County, 4.47 g.
Over 99.99% of the dioxin and dioxin-like compounds released by the titanium dioxide refinery are listed as being disposed of in "other on-site landfills." "Other landfills" (Section 5.5.1B on the TRI Form R) are defined by the EPA TRI program as "those landfills which are not authorized under Subtitle sub·ti·tle
1. A secondary, usually explanatory title, as of a literary work.
2. A printed translation of the dialogue of a foreign-language film shown at the bottom of the screen.
tr.v. C of the Resource Conservation and Recovery Act The Resource Conservation and Recovery Act (RCRA), enacted in 1976, is a Federal law of the United States contained in 42 U.S.C. §§6901-6992k. It is usually pronounced as "rick-rah" or "Wreck-rah. (RCRA RCRA Resource Conservation & Recovery Act of 1976
RCRA Resort and Commercial Recreation Association ) to accept hazardous wastes Hazardous waste
Any solid, liquid, or gaseous waste materials that, if improperly managed or disposed of, may pose substantial hazards to human health and the environment. Every industrial country in the world has had problems with managing hazardous wastes. . These landfills are commonly referred to as non-hazardous waste landfills and may be regulated under a variety of other Federal, state, and local programs." (USEPA TRI Explorer, http:// yosemite 1.epa.gov/oiaa/explorers_fe.nsf/Doc1/Other+Landfills?). The titanium dioxide refinery does not use RCRA Subtitle C landfills for disposal of dioxins, as indicated in Section 5.5.1A on the TRI Form R completed for dioxins in 2000 to 2003. The RCRA Subtitle C landfill is designed and authorized to accept hazardous waste for disposal, with requirements for lining to prevent leakage of landfill contents.
Given the large quantity of dioxin and dioxin-like compounds that are disposed of on-site, the type of disposal, the plant's proximity, and the lack of any other significant sources of dioxins in the vicinity, it seems likely that the titanium refinery is the most significant source of the dioxins found in St. Louis Bay. The distribution of dioxin and furan compounds in St. Louis Bay also implicates the refinery as the source. Such compounds could enter the bay by several pathways, including fallout fallout, minute particles of radioactive material produced by nuclear explosions (see atomic bomb; hydrogen bomb; Chernobyl) or by discharge from nuclear-power or atomic installations and scattered throughout the earth's atmosphere by winds and convection currents. from airborne emissions as well as fugitive emissions from surface-water runoff Runoff
The procedure of printing the end-of-day prices for every stock on an exchange onto ticker tape.
If the "tape is late" then it can take a long time to print off all the closing prices. or discharges. The latter inference is supported by the fact that the two highest concentrations of dioxins and furans in St. Louis Bay sediments were found at the two stations closest to the facility's surface-water discharge pipe Noun 1. discharge pipe - a pipe through which fluids can be discharged
hydrant - a discharge pipe with a valve and spout at which water may be drawn from the mains of waterworks (identified as the "sewer" noted in Fig. 1, Fig. 3). In addition, the two oyster samples with the highest lipid-adjusted I-TEQ values were from shellfish dredge sites 2 and 3, nearest to and close to, respectively, the facility's surface-water discharge pipe.
The potential for shellfish to accumulate greater concentrations of dioxin as the lipid content increases is suggested by the higher TEQ values for the measured dioxins and furans in sediments in and near St. Louis Bay. These WHO-TEQ values ranged from 4.17-11.78 pg per gram for in bay sites, with the highest sites recorded closest to the titanium dioxide refinery outfall (sediment collection sites 2 and 3, Fig. 3). However, relatively high sediment values were recorded at two open harvest sites near the mouth of St. Louis Bay (sediment collection sites 12 and 13). The elevated concentrations in sediments at these sites may be due to waterborne transport out of the bay and local current patterns in the vicinity of sediment collection sites 12 and 13. As noted earlier, during wave-tidal coupled action there is consistent flushing of the mouth of the bay into Mississippi Sound during all phases of the tide.
The US Environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise pollution, and radiation and to ensure the safe handling and Toxic Release Inventory (USEPA 2003) was examined for potential sources of chromium and nickel in the St. Louis Bay watershed. The titanium dioxide refinery on the northern shore of St. Louis Bay was found to release the largest amounts of chromium and nickel, and appears to be the only facility in close enough proximity to significantly affect the metals levels in St. Louis Bay. According to the figures reported by the titanium dioxide refinery to the USEPA Toxic Release Inventory, the refinery disposed of 304,928 kg (672,252 lb) of chromium compounds and 32,888 kg (72,505 lb) of nickel compounds in 2002. These are assumed to be metal chlorides based on the described manufacturing process for the refinery (USEPA 2001; MDEQ 2003). The majority of the chromium (303,907 kg = 670,000 lbs) and nickel (32,659 kg = 72,000 lb) were disposed of in Class l wells, whereas only 6.4 kg (14 lb) of chromium compounds and 45.5 kg (100 lb) of nickel compounds were reported to be released to surface water discharges (into St. Louis Bay) in 2002.
Multi-year data compilations were done to compare the amounts of chromium and nickel released by the titanium dioxide refinery with the two other sources of chromium and nickel in the counties bordering St. Louis Bay. For the years 1995 to 2003, the only years that the titanium dioxide refinery reported release of chromium and nickel compounds, the total quantity released was 238,872 kg (526,623 lbs) of nickel compounds and 3,168,142 kg (6,984,558 lbs) of chromium compounds. As noted earlier, most of the chromium and nickel compounds were injected into Class 1 wells. However, over this 9-y period, nickel compounds were also released as follows: 160 kg (353 lbs) stack or point source air emissions, 1260 kg (2778 lbs) discharged into St. Louis Bay, and 1996 kg (4400 lbs) placed in "other landfills" (not RCRA Subtitle C landfill). The corresponding amounts of chromium compounds for this 9 y period were: 131 kg (287 lbs) stack or point source air emissions, 156 kg (344 lbs) discharged into St. Louis Bay, and 10,841 kg (23,900 lbs) placed in "other landfills".
The Mississippi Power Company Watson Plant in Harrison County reported release of nickel compounds for the years 1998 to 2003 totaling 1299 kg (2864 lb) stack or point air emissions and 1134 kg (2501 lb) discharged to surface waters. The corresponding amounts for chromium compounds for these years (except no Cr release reported in 2002) were 946 kg (2085 lb) stack or point source air emissions and 349 kg (770 lb) discharged to receiving streams or water bodies. Plant Watson is located 28.2 km (17.5 air miles Air Miles
Brit points awarded on buying flight tickets and certain other products which can be used to pay for other flights ) east-northeast of Grassy Point in St. Louis Bay and at least 72.4 km (45 water miles) from Grassy Point via Biloxi Bay and Mississippi Sound. An examination of the prevailing winds The prevailing winds are the trends in speed and direction of wind over a particular point on the earth's surface. A region's prevailing winds often show global patterns of movement in the earth's atmosphere. Prevailing winds are the causes of waves as they push the ocean. in the area indicates that no significant heavy-metal components in the plant's air emissions would be expected to reach St. Louis Bay; likewise, the water distance and the lack of a direct water route to St. Louis Bay makes it highly improbable that the Bay would be affected by discharges from the Mississippi Power Company power plant. In addition to these two release routes, this plant places nickel and chromium compounds in surface impoundments; however, this release of chromium and nickel would not affect St. Louis Bay.
The other source of chromium compounds and nickel compounds in the vicinity is General Electric Plastics, located at Port Bienville in Hancock County, MS. This plastic polymer facility is located approximately 30.6 km (19 air miles) southwest of Grassy Point in northern St. Louis Bay and at least 45.1 km (28 water miles) via the Pearl River and Mississippi Sound from Grassy Point. This facility reports their toxic releases in ranges, as permitted by the EPA. These ranges are large enough to make it impossible to know how much nickel or chromium has been released to the air over the years reported (1999-2003). For each of these years, the amounts for chromium compounds and nickel compounds in fugitive air releases are noted to be 5.0-226.5 kg (11-499 lbs). The yearly amounts for both compounds released to water are noted to be 0.45 to 4.5 kg (1-10 lbs) for each of two water bodies. However, the total quantity released on-site is only 45.5 kg (100 lbs) of each metal compound per year, so the total amount of chromium compounds for the 5-y period is 227.0 kg (500 lbs), and for nickel compounds, the total released on-site for this period is also 227.0 kg (500 lbs). Given the relatively modest amounts of chromium and nickel released, coupled with the distances (via air and water) from St. Louis Bay, it seems unlikely that the releases from this facility affected the bay.
No other USEPA-permitted discharges of chromium or nickel compounds were identified from either Hancock or Harrison Counties. As noted, General Electric Plastics and Mississippi Power Company Watson Plant likely do not contribute to the metal contamination of St. Louis Bay. The distances via air and water over which these contaminants would have to travel to reach St. Louis Bay and the physical, meteorological me·te·or·ol·o·gy
The science that deals with the phenomena of the atmosphere, especially weather and weather conditions.
[French météorologie, from Greek , and hydrological hy·drol·o·gy
The scientific study of the properties, distribution, and effects of water on the earth's surface, in the soil and underlying rocks, and in the atmosphere. barriers to migration would preclude, in our opinion, any significant addition by these two sources to the metal contaminants in St. Louis Bay.
The titanium dioxide refinery has been discharging nickel and chromium compounds into the water of St. Louis Bay and into the air near the bay for at least 9 y. In addition, it seems possible that some of the nickel and chromium compounds placed in the landfills could, over time, leach out and contribute to the contamination of the bay.
Because the metals are likely to be metal chlorides, they would be expected to be soluble but likely precipitate and form particle-bound complexes when released and mixed into waters of increasing salinity. Thus, leakage of such compounds from the northern aspect of St. Louis Bay would likely result in a substantial portion of such metal chlorides being transported to the mouth of the bay and out of the bay to the higher salinity waters of Mississippi Sound where they would tend to precipitate out of solution. Therefore, the measured amounts of leachable and bioavailable chromium and nickel remaining in St. Louis Bay would represent only a fraction of the amount released into the bay. This further explains why a source of metal chlorides in the bay could result in higher accumulations of the metals in shellfish outside the bay than in the bay.
We also examined the potential for heavy-metal aerosols to reach St. Louis Bay from air-emission point sources along the Mississippi River Mississippi River
River, central U.S. It rises at Lake Itasca in Minnesota and flows south, meeting its major tributaries, the Missouri and the Ohio rivers, about halfway along its journey to the Gulf of Mexico. industrial corridor. That corridor runs from Baton Rouge Baton Rouge (băt`ən rzh) [Fr.,=red stick], city (1990 pop. 219,531), state capital and seat of East Baton Rouge parish, SE La. downriver down·riv·er
adv. & adj.
Toward or near the mouth of a river; in the direction of the current: swam downriver; a downriver canoe race.
Adv. 1. past New Orleans New Orleans (ôr`lēənz –lənz, ôrlēnz`), city (2006 pop. 187,525), coextensive with Orleans parish, SE La., between the Mississippi River and Lake Pontchartrain, 107 mi (172 km) by water from the river mouth; founded , Louisiana, and includes numerous petroleum refineries and chemical-manufacturing plants. Baton Rouge is 160 km (100 mi) due west of St. Louis Bay and New Orleans (the closest point along the industrial corridor) is 80 km (50 mi) southwest of the bay. Year 2002 EPA-TRI data (USEPA 2003) show that 134.4 kg (296 lb) of chromium and chromium compounds and 3,778 kg (8,322 lb) of nickel and nickel compounds were released from industrial sources within the "River Parishes" along the corridor.
We analyzed windrose data from the years 1987, 1988, 1990, and 1992 recorded at Louis Armstrong International Airport at New Orleans (MSY MSY Maximum Sustainable Yield
MSY New Orleans, LA, USA - Moisant International Airport (Airport Code)
MSY Male Specific Region of Y (genetics)
MSY Moisant Stock Yards in New Orleans ) to determine the potential for heavy-metal aerosols to reach St. Louis Bay from the industrial corridor. The windrose data show that winds that could potentially transport chromium and nickel aerosols occur only 11.8% of the time from the west through the southwest. Theoretically, only 11.8% of the chromium and nickel had the potential to be transported directly to the bay (15.8 kg = 34.9 lb of Ct; 445.8 kg = 982.0 lb of Ni). At least 75% of those westerly-through-southwesterly winds had velocities of 18.5 km/h (11.5 mi/h) or less; and the average velocity was 15.0 km/h (9.3 mi/h) for the entire period from all quadrants. Given the significant distances over which those aerosols would have to travel to reach St. Louis Bay (80-160 km; 50-100 mi), and the tendency of those aerosols to continually settle out before reaching the bay, we believe those aerosols would have no significant impact on chromium and nickel levels we found in sediments and shellfish in that bay.
Because of the specific source of metals, particularly chromium and nickel, the increase of these in sediments and particularly in shellfish, the association of dioxin with the refinery outfall, and the lack of other reporting large sources of these contaminants in the watershed, we conclude that the most likely source of these elevated contaminants in St. Louis Bay and the adjacent waters of Mississippi Sound is the titanium dioxide refinery on the northern shore of St. Louis Bay.
TABLE 1. Dioxin toxicity equivalent concentrations for St. Louis Bay, Mississippi shellfish samples. (1) I-TEQ (ND = 1/2) Shellfish WHO-TEQ I-TEQ [corected Sample (ND = 1/2) (ND = 1/2) for lipid Tract Percent [[pg/g] [[pg/g] [[pg/g] Number Lipid .sup.2] .sup.3] .sup.4] 1 0.35% 0.581 0.579 165.544 2 0.55% 0.444 0.838 152.407 3 0.35% 0.376 0.868 247.866 4 0.70% 0.381 0.379 54.147 5 0.66% 0.412 0.413 62.505 6 0.53% 0.395 0.400 75.474 7A 0.54% 0.378 0.364 67.429 7B 0.71% 0.463 0.451 63.568 7C 0.60% 0.382 0.379 63.118 8 0.34% 0.348 0.330 96.995 9C 0.46% 0.335 0.364 79.124 9D 0.64% 0.337 0.352 55.038 15 0.58% 0.312 0.294 50.627 16 0.46% 0.327 0.334 72.654 17 1.07% 0.405 0.391 36.561 Average all 0.392 0.449 89.537 samples: Average oysters only (all except #1): 0.378 0.440 84.108 (1) Toxicity equivalencies (WHO-TEQ and I-TEQ) calculated using World Health Organization toxic equivalence factors (WHO-TEF, Vanderberg et al. 1997) and International toxic equivalency factors (I-TEF, USEPA 1989), respectively. All values expressed as pg dioxin equivalent per g of shellfish tissue, wet weight. Congeners measured are shown in Table 2. (2) Values in this column are calculated using values for non-detects at 1/2 the detection limit (ND =1/2) (USEPA 1989). (3) Values in this column are given to provide a basis for comparison with Fiedler et al. (1997) who used I-TEF conversion factors and used 1/2 the limit of quantification for no detect congener values. (4) Values in this column are adjusted for lipid, assuming that all dioxins and furans are contained in lipids, and thus represent the calculated concentration using such an assumption. Thus the values in the far right column are comparable to the values published by Fiedler et al. (1997), after adjustment so that only the congeners measured in each study are included in a comparison. TABLE 2. Dioxin compounds and dioxin toxicity equivalent concentrations for St. Louis Bay, Mississippi sediment samples. (1,2) Sediment Collection Station Number Analyte 1 2 3 4 2378-TCDD 0.449 0.407 12378-PeCDD 1.22 1.7 1.78 1.74 123478-HxCDD 3.4 5.26 5.41 5.01 123678-HxCDD 6.49 9.67 10.6 9.75 123789-HxCDD 14.7 22.2 23.4 22.9 1234678-HxCDD 245 377 403 362 OCDD 5,590 7,950 7,910 6,920 2378-TCDF 0.462 1.2 0.805 0.755 12378-PeCDF 0.313 0.796 0.398 23478-PeCDF 0.353 0.787 0.582 0.532 123478-HxCDF 1.01 2.27 1.72 1.37 123678-HxCDF 0.989 1.76 1.6 1.36 234678-HxCDF 1.02 1.89 1.75 1.68 123789-HxCDF 0.356 0.505 0.395 1234678-HpCDF 7.25 15.1 13.5 14.5 1234789-HpCDF 2.04 1.46 1.31 OCDF 15.4 40.6 26.7 31.5 Sums (total dioxins and furans): 5,888 8,433 8,403 7,375 Average at in bay 6,594 stations (1 to 8): WHO-TEQ (ND = 1/2) 7.25 11.41 11.78 10.66 Sediment Collection Station Number Analyte 5 6 7 8 2378-TCDD 12378-PeCDD 0.717 0.803 1.31 1.37 123478-HxCDD 1.99 2.32 4.09 4.22 123678-HxCDD 3.63 4.53 8.57 8.2 123789-HxCDD 8.41 9.77 18.4 18.4 1234678-HxCDD 140 179 332 336 OCDD 3,460 4,120 6,750 7,140 2378-TCDF 0.301 0.389 0.612 0.657 12378-PeCDF 0.179 0.198 0.348 0.387 23478-PeCDF 0.232 0.249 0.484 0.489 123478-HxCDF 0.432 0.543 1.14 1.13 123678-HxCDF 0.449 0.568 1.23 234678-HxCDF 0.525 0.656 1.51 1.36 123789-HxCDF 0.184 1234678-HpCDF 3.91 5.08 11.4 10.5 1234789-HpCDF 0.441 0.453 1.19 1.08 OCDF 0.769 10.10 22.3 18.9 Sums (total dioxins and furans): 3,622 4,335 7,155 7,543 Average at in bay Average at out bay stations (1 to 8): stations (9 to 13): WHO-TEQ (ND = 1/2) 4.17 5.05 9.11 9.12 Sediment Collection Station Number Analyte 9 10 11 2378-TCDD 12378-PeCDD 0.286 1.31 123478-HxCDD 0.691 2.73 3.91 123678-HxCDD 1.39 5.34 6.98 123789-HxCDD 2.99 10.8 13.4 1234678-HxCDD 54.7 214 247 OCDD 1,220 4,330 4,630 2378-TCDF 0.152 12378-PeCDF 0.241 0.3 23478-PeCDF 0.346 0.493 123478-HxCDF 0.642 0.79 123678-HxCDF 0.213 0.777 234678-HxCDF 0.226 0.809 1.06 123789-HxCDF 0.293 1234678-HpCDF 1.74 0.692 7.22 1234789-HpCDF 0.138 0.623 0.733 OCDF 3.54 13 11.9 Sums (total dioxins and furans): 1,286 4,579 4,926 Average at in bay Average at out bay 5,864 stations (1 to 8): stations (9 to 13): WHO-TEQ (ND = 1/2) 1.62 4.93 7.18 Sediment Collection Station Number Analyte 12 13 2378-TCDD 0.564 12378-PeCDD 2.3 1.83 123478-HxCDD 7.36 5.27 123678-HxCDD 14.2 10.3 123789-HxCDD 29 18.7 1234678-HxCDD 546 384 OCDD 10,100 7,310 2378-TCDF 0.937 12378-PeCDF 0.575 0.473 23478-PeCDF 0.857 0.728 123478-HxCDF 1.62 1.33 123678-HxCDF 1.67 234678-HxCDF 2.24 1.69 123789-HxCDF 0.489 1234678-HpCDF 16.8 12.3 1234789-HpCDF 1.79 1.36 OCDF 31.1 25.5 Sums (total dioxins and furans): 10,757 7,774 Average at in bay stations (1 to 8): WHO-TEQ (ND = 1/2) 15.33 10.56 (1) Toxicity equivalent factors (WHO-TEQ) calculated using World Health Organization toxic equivalence factors (TEFs). All values expressed in pg analyte per gram of sediment dry weight. TEQ values calculated using 1/2 the detection limit value (ND = I/2) for non-detect analytes (USEPA 1989). (2) Blanks in analyte table indicate non-detects or values below the detection limit. TABLE 3. Metals in shellfish in St. Louis Bay, Mississippi and out of bay locations. (1) Metal Element Measured in shell- fish (micro]g/g wet weight) (2) Shellfish Collection Site Number and Species Ag As Be Cd 1978 values for Eastern oysters (Crassostrea virginica) in St. Louis Bay 0.1222 <0.08 1.61 1978 values for wedge clams (Rangia cuniata) in St. Louis Bay 0.056 <0.08 <0.05 3C Wedge clams (n = 4) 0.39 0.93 <0.04 0.12 7A Eastern oysters (n = 12) 0.57 0.63 <0.04 1.12 7A Wedge clams (n = 5) 2.01 1.22 <0.04 0.10 7B Eastern oysters (n = 6) 0.53 0.55 <0.04 0.95 7B Ischadium recurvum (hooked mussels) (n = 15) 0.05 0.74 <0.04 0.24 7C Eastern oysters (n = 3) 0.30 0.30 <0.04 0.62 9B Eastern oysters (n = 12) 0.58 0.70 <0.04 0.92 15 Eastern oysters (n = 10) 0.71 0.77 <0.04 1.03 15 Hooked mussels (n = 15) 0.05 0.90 <0.04 0.17 16 Eastern oysters (n = 5) 0.87 0.99 <0.04 1.37 Average in bay Eastern oysters, this study 0.47 0.49 <0.04 0.90 Average in bay wedge clams, this study 1.20 1.08 <0.04 0.11 Percent value, 2004 compared to 1978, Eastern oysters (3) 404% 56% Percent value, 2004 compared to 1978, wedge clams 1920% 220% Metal Element Measured in Shell- fish (micro]g/g wet weight) (2) Shellfish Collection Site Number and Species Cr Cu Hg Ni 1978 values for Eastern oysters (Crassostrea virginica) in St. Louis Bay <0.1 31.5 0.0746 <0.2 1978 values for wedge clams (Rangia cuniata) in St. Louis Bay NR 2.46 0.107 <0.2 3C Wedge clams (n = 4) 2.30 3.60 0.04 3.30 7A Eastern oysters (n = 12) 1.20 37.00 0.01 0.90 7A Wedge clams (n = 5) 1.00 4.00 0.03 1.60 7B Eastern oysters (n = 6) 1.70 34.00 0.02 1.40 7B Ischadium recurvum (hooked mussels) (n = 15) 0.50 1.70 0.02 0.60 7C Eastern oysters (n = 3) 0.60 22.00 <0.01 0.50 9B Eastern oysters (n = 12) 0.80 33.00 <0.01 0.80 15 Eastern oysters (n = 10) 0.20 28.00 <0.01 0.40 15 Hooked mussels (n = 15) 0.90 1.80 0.02 0.50 16 Eastern oysters (n = 5) 7.70 49.30 0.02 7.30 Average in bay Eastern oysters, this study 1.17 31.00 <0.01 0.93 Average in bay wedge clams, this study 1.65 3.80 0.12 2.45 Percent value, 2004 compared to 1978, Eastern oysters (3) >1170% 98% 17% >467% Percent value, 2004 compared to 1978, wedge clams 154% 112% >1225% Metal Element Measured in Shell- fish (micro]g/g wet weight) (2) Shellfish Collection Site Number and Species Ph Sb Se Zn 1978 values for Eastern oysters (Crassostrea virginica) in St. Louis Bay <0.5 <0.05 0.248 821 1978 values for wedge clams (Rangia cuniata) in St. Louis Bay <0.5 <0.05 0.493 16.5 3C Wedge clams (n = 4) <0.20 <0.04 0.50 9.90 7A Eastern oysters (n = 12) <0.20 <0.04 0.40 543.00 7A Wedge clams (n = 5) <0.20 <0.04 1.10 8.50 7B Eastern oysters (n = 6) <0.20 <0.04 0.30 549.00 7B Ischadium recurvum (hooked mussels) (n = 15) <0.20 <0.04 0.60 7.10 7C Eastern oysters (n = 3) <0.20 <0.04 <0.40 342.00 9B Eastern oysters (n = 12) <0.20 <0.04 0.50 486.00 15 Eastern oysters (n = 10) <0.20 <0.04 0.60 252.00 15 Hooked mussels (n = 15) <0.20 <0.04 0.90 7.90 16 Eastern oysters (n = 5) <0.20 <0.04 0.60 580.00 Average in bay Eastern oysters, this study <0.20 <0.04 0.37 478.00 Average in bay wedge clams, this study <0.20 <0.04 0.80 9.2 Percent value, 2004 compared to 1978, Eastern oysters (3) 148% 58% Percent value, 2004 compared to 1978, wedge clams 162% 56% (1) Data set 2, as referenced in text, extraction using EPA Method 3050B. (2) Values listed as < indicate the detection limit and therefore the concentration is less than the detection limit. (3) Change values listed as > indicate that the percent value in 2004 is at least the indicated percentage in comparison to the 1978 values because the latter were below the indicated detection limits. Blank values in the comparison rows indicate that both 1978 and 2004 values were below the limits of detection. TABLE 4. Metals in shellfish in St. Louis Bay, Mississippi and out of bay locations. (1) Metal Measured in Tissue ([micro]g/g wet weight) (2) Ag As Avg. of 4 in-bay sites (7A, 7B, 7C, 8) [+ or -] SD (3) 0.31 [+ or -] 0.02 0.34 [+ or -] 0.03 Range of same 4 in-bay sites 0.29-0.34 0.32-0.39 Avg. of 3 sites south of bay (9, 15, 17) [+ or -] SD (3) 0.31 [+ or -] 0.01 0.44 [+ or -] 0.10 Range of same 3 sites south of bay (4) 0.21-0.40 0.34-0.53 Metal Measured in Tissue ([micro]g/g wet weight) (2) Ni Pb Avg. of 6 in-bay sites (1, 2, 3, 5, 7, 8) [+ or -] SD (3) 2.75 [+ or -] 1.96 0.08 [+ or -] 0.02 Range of same 4 in-bay sites 0.92-5.28 0.06-0.10 Avg. of 3 sites south of bay (9, 11, 13) [+ or -] SD (3) 4.43 [+ or -] 2.70 0.05 [+ or -] 0.01 Range of same 3 sites south of bay (4) 2.67-7.54 0.04-0.07 Metal Measured in Tissue ([micro]g/g wet weight) (2) Be Cd Avg. of 4 in-bay sites (7A, 7B, 7C, 8) [+ or -] SD (3) 0.003 [+ or -] 0.001 0.63 [+ or -] 0.08 Range of same 4 in-bay sites 0.002-0.003 0.54-0.73 Avg. of 3 sites south of bay (9, 15, 17) [+ or -] SD (3) 0.002 [+ or -] 0.000 0.53 [+ or -] 0.12 Range of same 3 sites south of bay (4) 0.0014 (U)-0.002 0.46-0.66 Metal Measured in Tissue ([micro]g/g wet weight) (2) Sb Se Avg. of 6 in-bay sites (1, 2, 3, 5, 7, 8) [+ or -] SD (3) 0.005 [+ or -] 0.00 0.21 [+ or -] .01 Range of same 4 in-bay sites 0.005 (U) 0.20-0.22 Avg. of 3 sites south of bay (9, 11, 13) [+ or -] SD (3) 0.005 [+ or -] 0.00 0.32 [+ or -] 0.093 Range of same 3 sites south of bay (4) 0.005 (U) 0.23-0.42 Metal Measured in Tissue ([micro]g/g wet weight) (2) Cr Cu Avg. of 4 in-bay sites (7A, 7B, 7C, 8) [+ or -] SD (3) 4.213 [+ or -] 3.35 20.5 [+ or -] 1.01 Range of same 4 in-bay sites 1.15-8.68 19.5-21.7 Avg. of 3 sites south of bay (9, 15, 17) [+ or -] SD (3) 6.91 [+ or -] 4.68 17.2 [+ or -] 5.70 Range of same 3 sites south of bay (4) 3.86-12.30 11.6-23.0 Metal Measured in Tissue ([micro]g/g wet weight) (2) TI Zn Avg. of 6 in-bay sites (1, 2, 3, 5, 7, 8) [+ or -] SD (3) 0.001 [+ or -] .000 461 [+ or -] 68 Range of same 4 in-bay sites 0.001-0.002 407-550 Avg. of 3 sites south of bay (9, 11, 13) [+ or -] SD (3) 0.002 [+ or -] 0.001 256 [+ or -] 101 Range of same 3 sites south of bay (4) 0.001-0.002 159-361 Metal Measured in Tissue ([micro]g/g wet weight) (2) Hg Avg. of 4 in-bay sites (7A, 7B, 7C, 8) [+ or -] SD (3) 0.006 [+ or -] 0.001 Range of same 4 in-bay sites 0.005-0.007 Avg. of 3 sites south of bay (9, 15, 17) [+ or -] SD (3) 0.006 [+ or -] 0.002 Range of same 3 sites south of bay (4) 0.004-0.007 Metal Measured in Tissue ([micro]g/g wet weight) (2) Avg. of 6 in-bay sites (1, 2, 3, 5, 7, 8) [+ or -] SD (3) Range of same 4 in-bay sites Avg. of 3 sites south of bay (9, 11, 13) [+ or -] SD (3) Range of same 3 sites south of bay (4) (1) Data set 1, as referenced in text, extraction using hydrofluoric acid method. (2) Values followed by U indicate that the value is the detection limit and the value for that indicated site and element is thus below the detection limit. (3) Site numbers refer to site locations shown in Figure 3. (4) For silver, arsenic, cadmium, chromium, nickel, and selenium the highest values for open harvest areas south of St. Louis Bay, indicated by the upper range number, were for shellfish collection site 15, as indicated on Figure 2. TABLE 5. Comparison of sediment metals in St. Louis Bay 1978 versus 2004. (1) Metal Element Measured in Sediment ([micro]g/g dry weight) As Be Cd Cr 1978 Average Value in St. Louis Bay (SLB) 7.05 0.789 <0.087 10.67 2004 Value in SLB (Site 2) 8.55 1.05 <0.50 16.50 Percent value, 2004 compared to 1978 (in bay values) 121% 133% 155% 2004 Average Value outside SLB (Sites 12 & 13) 6.1 0.85 <0.5 15 Metal Element Measured in Sediment ([micro]g/g dry weight) Ni Pb Sb Se 1978 Average Value in SLB 9.35 15.4 <0.025 <0.013 2004 Average Value in SLB 11.5 17 <0.5 <1.0 Percent value, 2004 compared to 1978 (in bay values) 123% 111% 2004 Average Value outside SLB (Sites 12 & 13) 13.5 13 <0.5 <1.0 Metal Element Measured in Sediment ([micro]g/g dry weight) Cu Hg 1978 Average Value in St. Louis Bay (SLB) 10.04 0.107 2004 Value in SLB (Site 2) 9 0.095 Percent value, 2004 compared to 1978 (in bay values) 90% 88.8% 2004 Average Value outside SLB (Sites 12 & 13) 10 0.090 Metal Element Measured in Sediment ([micro]g/g dry weight) Zn 1978 Average Value in SLB 69.35 2004 Average Value in SLB 55.5 Percent value, 2004 compared to 1978 (in bay values) 80% 2004 Average Value outside SLB (Sites 12 & 13) 53 (1) Data set 2, as referenced in text, extraction using EPA Method 3050B. TABLE 6. Estimated safe consumption levels of oysters from St. Louis Bay and near Bay open harvest areas. (1) Nickel Nickel (general (hypersen- Chromium popula- sitive indi- III (2) tion) (3) viduals) (3) Estimated safe and adequate daily dietary intake (ESADDI): 200 1200 50 [micro]g/ [micro]g/ [micro]g/ person/day person/day person/day Average concentration in oysters from in Bay sites ([micro]g/g wet weight) 1.17 0.93 0.93 Specific consumption level of concern from in Bay sites (g oysters per day) 171 1290 54 Number of oysters (34 g) consumed daily to reach consumption level of concern 5.0 38.0 1.6 Maximum concentration in oysters from in Bay sites ([micro]/g wet weight) 1.7 1.4 1.4 Specific consumption level of concern from in Bay sites (g oysters per day) 118 857 36 Number of oysters (34 g) consumed daily to reach consumption level of concern 3.5 25.2 1.1 Average concentration in oysters from near Bay sites ([micro]g/g wet weight) 2.9 2.8 2.8 Specific consumption level of concern from near Bay sites (g oysters per day) 69 424 18 Number of oysters (34 g) consumed daily to reach consumption level of concern 2.0 12.5 0.5 Maximum concentration in oysters from near Bay site ([micro]g/g wet weight) 7.7 7.3 7.3 Specific consumption level of concern from near Bay sites (g oysters per day) 26 164 7 Number of oysters (34 g) consumed daily to reach consumption level of concern 0.8 4.8 0.2 (1) These calculations of estimated safe consumption levels of oysters are based on the more conservative metals data set 2. (2, 3) USFDA 1993. Values from guidance documents for chromium and nickel in shellfish (also PDR 2004, Beers & Berkow, 2004).
The authors thank Mr. Glen Strong for providing and operating the boat used for sample collection and Mr. Joe Jewell and Ms. Traci Floyd of the Mississippi Department of Marine Resources who provided the scientific collection permit used for these studies. The Enforcement Division of the MDMR MDMR Mississippi Department of Marine Resources
MDMR multi dimensional mobility robot (US DARPA program)
MDMR M-Day Materiel Requirement assisted in ensuring that sample collection trips were logged as required by Mississippi law. Mr. James Humphrey The name James Humphrey may refer to:
The City of Dallas (pronounced [ˈdæl.əs] or [ˈdæl. to AquaTechnics Inc., Sequim, Washington and to Gulf Environmental Associates, Ocean Springs, Mississippi Ocean Springs is a city in Jackson County, Mississippi (USA), about 2 miles east of Biloxi. It is part of the Pascagoula, Mississippi Metropolitan Statistical Area. The population was 17,225 at the 2000 census.
The town has a reputation as an "arts community. .
ASTM. 2003. Method D422-63 (2002) Standard test method for particle-size analysis of Soils. ASTM International ASTM International (ASTM) is an international standards developing organization that develops and publishes voluntary technical standards for a wide range of materials, products, systems, and services. , West Conshohocken, Pennsylvania West Conshohocken is a borough in Montgomery County, Pennsylvania, United States. The population was 1,462 in 1880; 2,482 in 1950; 1,516 in 1980; 1,294 in 1990; and 1,446 at the 2000 census. .
Barber, B. J., S. E. Ford & H. H. Haskin. 1988a. Effects of the parasite MSX MSX - Microsoft Extended (Haplosporidium nelsoni) on oyster (Crassostrea virginica) energy metabolism Energy metabolism
Energy metabolism, or bioenergetics, is the study of energy changes that accompany biochemical reactions. Energy sustains the work of biosynthesis of cellular and extracellular components, the transport of ions and organic chemicals against . I. Condition index and relative fecundity fecundity /fe·cun·di·ty/ (fe-kun´dit-e)
1. in demography, the physiological ability to reproduce, as opposed to fertility.
2. ability to produce offspring rapidly and in large numbers. . J. Shellfish Res. 7:25-31.
Barber, B. J., S. E. Ford & H. H. Haskin. 1988b. Effects of the parasite MSX (Haplosporidium nelsoni) on oyster (Crassostrea virginica) energy metabolism. II. Tissue biochemical composition. Comp. Biochem. Physiology 91A:603-608.
Beers, M. H. & R. Berkow, editors. 2004. The Merck manual of fiagnosis and therapy. 17th ed. Merck & Co. Inc. Available at: http://www. merck.com/mrkshared/mmanual/home.jsp.
Cobb, M. & C. A. Blain. 2002. Simulating wave-tide induced circulation in Bay St. Louis, MS with a coupled hydrodynamic-wave model. Marine Tech. Sci. 3:1494-1500.
Comber, S. D. W., A. J. Dobbs & S. Lewis. 1996. Guideline Values for Sediments Contaminated with Dioxins and Furans. Ecotoxicology The term ecotoxicology was coined by Truhaut in 1969, who defined it as "the branch of toxicology concerned with the study of toxic effects, caused by natural or synthetic pollutants, to the constituents of ecosystems, animal (including human), vegetable and microbial, in an and Environmental Safety 35:102-108.
Cordi, J. A., M. A. Meylan & W. C. Isphording. 2003. Metal distribution and metal site partitioning, Mobile Bay surface sediments: Gulf Coast Association of Geological Societies Transactions. 53:145-159.
EC. 2002. Commission recommendation of 4 March 2002 on the reduction of the presence of dioxins, furans and PCBs in feedingstuffs and foodstuffs foodstuffs npl → comestibles mpl
foodstuffs npl → denrées fpl alimentaires
foodstuffs food npl → . (2002/201/EC). Official Journal of the European Communities European Community: see European Union.
European Community (EC)
Organization formed in 1967 with the merger of the European Economic Community, European Coal and Steel Community, and European Atomic Energy Community. L67/69. Available at: http://europa.eu.int/eur-lex/pri/en/oj/dat/2002/ 1_067/1_06720020309en00690073.pdf
Eleuterius, C. K. 1976. Mississippi Sound. Salinity distribution and indicated flow patterns. Report No. MASGP-76-023. Mississippi-Alabama Sea Grant Consortium, Ocean Springs, Mississippi.
Fiedler, H., K. R. Cooper, S. Bergek & C. Rappe. 1997. Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) in food samples collected in southern Mississippi, USA. Chemosphere chemosphere: see atmosphere. 34(5-7): 1411-1419.
Flyvholm, M. A., G. D. Nielsen & A. Andersen. 1984. Nickel content of food and estimation of dietary intake. Z Lebensm Unters Forsch. 179(6):427-431.
Huanxin, W., Z. Lejun & B. J. Presley. 2000. Bioaccumulation bi·o·ac·cu·mu·la·tion
The increase in the concentration of a substance, especially a contaminant, in an organism or in the food chain over time. of heavy metals in oyster (Crassostrea virginica) tissue and shell. Environ. Geol. 39(11):1216-1226.
Isphording, W. C. 1985. Sediments and sediment chemistry of Mississippi Sound. Report No. MASGP-85-011. Report, Mississippi-Alabama SEA GRANT Consortium, Ocean Springs, Mississippi.
Jensen, E. & P. M. Bolgar. 2001. Exposure assessment of dioxins/furans consumed in dairy foods and fish. Food Additives food additives, substances added to foods by manufacturers to prevent spoilage or to enhance appearance, taste, texture, or nutritive value. By quantity, the most common food additives are flavorings, which include spices, vinegar, synthetic flavors, and, in the and Contaminants 18(5):395-403.
Lytle, T. F. & S. J. Lytle. 1982. Heavy metals in oysters and clams of St. Louis Bay, Mississippi. Bulletin of Environmental Contamination and Toxicology toxicology, study of poisons, or toxins, from the standpoint of detection, isolation, identification, and determination of their effects on the human body. Toxicology may be considered the branch of pharmacology devoted to the study of the poisonous effects of drugs. 29:50-57.
MDEQ. 2003. RCRA part B application, Dupont Delisle Plant, EPA ID MD096046792. Mississippi Department of Environmental Quality. Available at: http://www.deq.state.ms.us/MDEQ.nsf/0/ FE16C7F C7F Commander Seventh Fleet 9249D1A9086256E9F0048946F/$file/Permit+Attach. +B.pdf?OpenElement
NOAA. 2001. Nautical Chart 11371: Lake Borgne and approaches--Cat Island to Point aux Herbes, ed. 35. National Oceanic and Atmospheric Administration, National Ocean Survey, Washington, DC.
NOAA. 2004. Nautical chart 11372 and 11372A--Dog Keys pass to Waveland, ed. 31. National Oceanic and Atmospheric Administration, National Ocean Survey, Washington, DC.
PDR. 2004. Physicians desk reference, on line. Available at: http:// www.pdr.net/pdrnet/librarian
Pearson, R. F., D. L. Swackhamer & S. J. Eisenreich. 1995. Concentrations, inventories and accumulations of polychlorinated dibenzo-p-dioxins and dibenzofurans in the sediments of the Great Lakes. Organohalogen Compounds 24:267-271.
Pinsky, P. & M. N. Lorber. 1998. A model to evaluate past exposure to 2,3,7,8-TCDD. Journal of Exposure Analysis and Environmental Epidemiology 8(2): 187-206.
PSEP. 1997. Recommended guidelines for sampling marine sediment, water column, and tissue in Puget Sound. Puget Sound water quality action team report prepared for Puget Sound Estuary estuary (ĕs`chĕr'ē), partially enclosed coastal body of water, having an open connection with the ocean, where freshwater from inland is mixed with saltwater from the sea. Program, US Enviromnental Protection Agency, Region 10, Seattle, Washington. 47 pp.
Sinkkonen, S. & J. Paasivirta. 2000. Degradation half-life times of PCDDs, PCDFs and PCBs for environmental fate modeling. Chemosphere 40: 943-949.
Smith, R. M., P. W. O'Keefe, D. Hilker, S. Conner & E. Posner. 1995. Direct and indirect contributions of atmospheric PCDDs and PCDFs to Hudson River Hudson River
River, New York, U.S. Originating in the Adirondack Mountains and flowing for about 315 mi (507 km) to New York City, it was named for Henry Hudson, who explored it in 1609. Dutch settlement of the Hudson valley began in 1629. national estuarine research reserve The National Estuarine Research Reserve program of the United States government under the auspices of the National Marine Protected Areas Initiative. The program establishes federal-state partnerships under the Coastal Zone Management Act to create a system of estuarine research sediment cores. Organohalogen Compounds 24:141-145.
Stephensen, M. D., M. Martin, S. E. Lange, A. R. Flegal & J. H. Martin. 1979. California mussel The California mussel (Mytilus californianus) is a large edible saltwater mussel or marine bivalve mollusk in the family Mytilidae.
This species is native to the west coast of North America, occuring from northern Mexico to the Aleutian Islands of Alaska. watch 1977-1978, Volume II: Trace metals concentrations in the California Mussel, Mytilus californianus. State Water Resources Control Board Water Quality Monitoring Report No. 79-22. Southern California Southern California, also colloquially known as SoCal, is the southern portion of the U.S. state of California. Centered on the cities of Los Angeles and San Diego, Southern California is home to nearly 24 million people and is the nation's second most populated region, Water Research Control Board.
USEPA. 1979. Residue Volatile. Method 160.4. United States Environmental Protection Agency. Washington, DC. Available at: http:// infotrek.er.usgs.gov/pls/portal30/NEMI_PORTAL.RPT RPT - Unify. Report Writer Language. _METHOD_ANALYTE_LIST.show
USEPA. 1989. Interim procedures for estimating risks associated with exposures to mixtures of chlorinated chlorinated /chlo·ri·nat·ed/ (klor´i-nat?ed) treated or charged with chlorine.
charged with chlorine.
some, e.g. dibenzo-p-dioxins and dibenzofurans (CDDs and CDFs) and 1989 update. Washington, DC: Risk Assessment Forum. EPA/625/3-89/016). See also http://www.epa.gov/ wtc/dioxin/dioxin_fact_sheet.html for discussion of USEPA discussion of toxic equivalency factors.
USEPA. 1991a. Mercury in sediment by cold vapor (CV.AAS). Method 245.5. United States Environmental Protection Agency, Washington, DC. Report No. 600/4-91-010
USEPA. 1991b. Chlorinated dioxins and furans in the general US population: NHATS FY87 results. Report EPA-560/5-91-003. Office of Toxic Substances, United States Environmental Protection Agency, Washington, DC.
USEPA. 1994. Trace elements Trace elements
A group of elements that are present in the human body in very small amounts but are nonetheless important to good health. They include chromium, copper, cobalt, iodine, iron, selenium, and zinc. Trace elements are also called micronutrients. in waters and wastes /ICP/MS. Method 200.8. United States Environmental Protection Agency. Washington, DC. Available at: http://infotrek.er.usgs.gov/pls/portal30/ NEMI NEMI National Electronics Manufacturing Initiative
NEMI National Environmental Methods Index _PORTAL.RPT_METHOD_ANALYTE_LIST.show
USEPA. 1996a. Trace elements in ambient waters by ICP/MS. Method 1638. United States Environmental Protection Agency. Washington, DC. Available at: http://infotrek.er.usgs.gov/pls/portal30/ NEMI_PORTAL.RPT_METHOD_ANALYTE_LIST.show
USEPA. 1996b. Acid digestion of sediments, sludges and soils. Method 3050B, SW846, Ch. 3.2. United States Environmental Protection Agency. Washington, DC. http://www.epa.gov/epaoswer/hazwaste/ test/pdfs/3050b.pdf
USEPA. 1997. Polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) by high-resolution gas chromatography/ high resolution mass spectrometry mass spectrometry
or mass spectroscopy
Analytic technique by which chemical substances are identified by sorting gaseous ions by mass using electric and magnetic fields. (HRGC/HRMS). SW846, Method 8290. United States Environmental Protection Agency. Washington, DC. Available at: http://www.epa.gov/epaoswer/hazwaste/test/pdfs/ 8290.pdf
USEPA. 1999. Method 1668, Revision A: Chlorinated biphenyl biphenyl /bi·phen·yl/ (-fen´il) diphenyl.
polychlorinated biphenyl (PCB) any of a group of chlorinated derivatives of biphenyl, used as heat-transfer agents and electrical insulators; they are congeners in water, soil, sediment, and tissue by HRGC/HRMS. EPA No. EPA-821-R-00-002. Office of Water, United States Environmental Protection Agency, Washington, DC.
USEPA. 2001. Final Titanium dioxide listing background document for the inorganic chemical listing determination. United States Environmental Protection Agency, Washington, DC. Available at: http://www.epa. gov/apaoswer/hazwaste/id/inorchem/pdfs/tio2-bd.pdf
USEPA. 2003. Toxic release inventory (http://www.epa.gov/tri). United States Environmental Protection Agency. Washington, DC.
USFDA. 1997. Note to: Egg producers and catfish farmers and processors. Subject: Dioxin contaminated animal feed. July 8, 1997. US Food and Drug Administration. Center for Food Safety and Applied Nutrition The Center for Food Safety and Applied Nutrition (CFSAN, pronounced sif'-san) is the branch of the Food and Drug Administration (FDA) which regulates food, dietary supplements, and cosmetics.
"Food" within the context of FDA is a very broad term with some limitations. . http://www.cfsan.fda.gov/nird/dioxltr.html
USFDA. 1993a. Guidance document for arsenic in shellfish. Center for Food Safety and Applied Nutrition. United States Food and Drug Administration United States Food and Drug Administration (FDA),
n.pr a unit of the Public Health Service created to protect the health of the nation against impure and unsafe foods, drugs, and cosmetics. . Washington, DC.
USFDA. 1993b. Guidance document for chromium in shellfish. Center for Food Safety and Applied Nutrition. United States Food and Drug Administration. Washington, DC.
USFDA. 1993c. Guidance document for nickel in shellfish. Center for Food Safety and Applied Nutrition. United States Food and Drug Administration. Washington, DC.
USFDA. 2000. Dioxin and PCB. Available at: http://www.fda.gov/cvm/ index/dioxin/dioxin.html
Vanden Berg, M., L. Birnbaum, A. T. C. Bosveld, B. Brunstrom, P. Cook, M. Feeley, J. P. Giesy, A. Hanberg, R. Hasegawa, S. W. Kennedy, T. Kubiak, J. C. Larsen, F. X. R. van Leeuwen, A. K. D. Liem, C. Nolt, R. E. Peterson, L. Poellinger, S. Safe, D. Schrenk, D. Tillitt, M. Tysklind, M. Younes, F. Waern & T. Zacharewski. 1998. Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife. Environmental Health Perspectives 106 (12). EHP EHP
1. effective horsepower
2. electric horsepower Online: http://ehp.niehs.nih.gov/members/1998/106p775-792vandenberg/ vandenberg-full.html
Winters, D. L., S. Anderson, M. Lorber, J. Ferrario & C. Byrne. 1998. Trends in dioxin and PCB concentrations in meat samples from several decades of the 20th century. Organohalogen Compounds 38:75-77.
RALPH ELSTON, (1) * EDWIN W. CAKE, JR, (2) KAREN HUMPHREY Karen Humphrey was mayor of Fresno, California between 1989 and 1993. She was Fresno's first and to date only female mayor. She lost re-election to businessman Jim Patterson. List of Fresno Mayors
(1) AquaTechnics Inc., PO Box 687, Carlsborg, Washington Carlsborg is a census-designated place (CDP) in Clallam County, Washington, United States. The population was 855 at the 2000 census. Geography
Carlsborg is located at (48.084085, -123.170290)GR1. 98324; (2) Gulf Environmental Associates, 2510 Ridgewood Road, Ocean Springs, Mississippi 39564; (3) Department of Earth Sciences, University of South Alabama The University of South Alabama is a public, doctoral-level university in Mobile, Alabama, USA. It was created by the Alabama Legislature in 1963, and replaced existing extension programs operated in Mobile by the University of Alabama. , Mobile, Alabama 36688; (4) Rensel Associates Aquatic Sciences, 4209 234th Street NE, Arlington, Washington Arlington is a city located in northern Snohomish County, Washington, USA, bordered by the city of Marysville to the south. As of the 2004 census, the city had a total population of 14,491. , 98223
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