The Effects of Home Lead Abatements on Childhood Blood Lead Levels: A Retrospective Follow-up Study.Abstract Home abatement A reduction, a decrease, or a diminution. The suspension or cessation, in whole or in part, of a continuing charge, such as rent. With respect to estates, an abatement is a proportional diminution or reduction of the monetary legacies, a disposition of property by will, when is the environmental intervention most commonly mandated by law for children with lead poisoning lead poisoning or plumbism (plŭm`bĭz'əm), intoxication of the system by organic compounds containing lead. . Previous studies of abatement efficacy, however, have yielded inconsistent results and have left doubt about the long-term effectiveness of this intervention in reducing children's blood lead levels. For this study, the authors analyzed an·a·lyze tr.v. an·a·lyzed, an·a·lyz·ing, an·a·lyz·es 1. To examine methodically by separating into parts and studying their interrelations. 2. Chemistry To make a chemical analysis of. 3. 488 children six years old or less who had been reported to the New Jersey Department of Health and Senior Services from 1993 to 1997 with blood lead levels of 30 to 44 micrograms per deciliter deciliter /dec·i·li·ter/ (dL) (des´i-le?ter) one tenth (10minus;1) of a liter; 100 milliliters. Deciliter (dL) 100 cubic centimeters (cc). Mentioned in: Hypercholesterolemia ([micro]g/dL); each of the children analyzed also had a follow-up blood lead test at least two months after abatement if an abatement was completed, or two months after baseline if an abatement was not completed. Although home abatements were recommended for all children, they were not completed in 118 cases. A significant difference (p [less than] .01) was seen in the mean declines of blood lead levels between children in abated Abated, an ancient technical term applied in masonry and metal work to those portions which are sunk beneath the surface, as in inscriptions where the ground is sunk round the letters so as to leave the letters or ornament in relief. From 1911 Encyclopædia Britannica homes (-10.1 [micro]g/dL, or -28.5 percent) and those in unabated un·a·bat·ed adj. Sustaining an original intensity or maintaining full force with no decrease: an unabated windstorm; a battle fought with unabated violence. homes (-7.3 [micro]g/dL, or -20.8 percent). This difference was partially due to longer follow-up in the group that received abatement. When this difference was adjusted in a multiple regression Multiple regression The estimated relationship between a dependent variable and more than one explanatory variable. for age, time to follow-up, baseline blood lead level, socioeconomic so·ci·o·ec·o·nom·ic adj. Of or involving both social and economic factors. socioeconomic Adjective of or involving economic and social factors Adj. 1. factors, and season-with time to follow-up restricted to 70--400 days--the overall difference in decline of blood lead levels decreased from 7.7 percent to two percent. When the same restriction was applied with adjustment for the same confounders in a logistic regression In statistics, logistic regression is a regression model for binomially distributed response/dependent variables. It is useful for modeling the probability of an event occurring as a function of other factors. and the probability of a decline of [greater than]4 [micro]g/dL was modeled, abatement had minimal effect (odds ratio = 1.4; 95 percent confidence interval confidence interval, n a statistical device used to determine the range within which an acceptable datum would fall. Confidence intervals are usually expressed in percentages, typically 95% or 99%. = 0.7, 2.5). Thus, lead paint abatements, as required in New Jersey from 1993 to 1997, are of only modest efficacy in reducing children's blood lead levels. Stronger regulations, better enforcement, and more attention to lead-contaminated dust should be evaluated as ways of better protecting lead-exposed children. Introduction Abatement, the removal of lead paint from homes of lead-exposed children, is a strategy state and municipal health departments across 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. commonly use to reduce lead risk in the home environment. In most jurisdictions, licensed clinical laboratories are required to report to a health authority when they discover blood lead levels above a specified action level; the jurisdictions then require inspections of the homes of affected children for lead sources. If lead based paint is present, an abatement may be ordered. While a carefully performed abatement will substantially reduce lead hazards (Farfel far·fel or far·fal n. Noodles shaped like small grains or pellets. [Yiddish farfl, from Middle High German varveln.] and Chisolm, 1991; Farfel, Chisolm, & Rohde, 1994), the financial and legal exigencies affecting communities often compromise the timeliness, quality, and complete ness of the work that actually gets done. As blood lead levels in the United States have fallen over recent years, the Years, The the seven decades of Eleanor Pargiter’s life. [Br. Lit.: Benét, 1109] See : Time proportion of lead-exposed children who have had grossly elevated blood lead levels has declined (Bailey et al., 1994). There is considerable evidence that lead-contaminated dust is an important vector for children identified with blood lead levels below 30 micrograms per deciliter ([micro]g/dL), who comprise the large majority of the children identified as lead-exposed (Lanphear et al., 1998). In urban environments where the density of lead-painted houses has been high, and where automobile exhaust has contributed additional lead to the soil, much of this dust is tracked or blown into houses from outside (Adgate et al., 1998; Adgate, Lioy, & Rhoads, 1998). Regular cleaning of lead-contaminated dust by lay workers with appropriate training has been shown in con trolled field trials to yield a 16 to 33 percent reduction in the blood lead levels of toddlers (Charney, Farfel, Jackson, & Kessler, 1983; Rhoads et al., 1999). Paint abatement does not directly address these important routes of exposure and might be expected to be less effective at the lower blood lead levels that were of concern in the 1990s than at the higher blood lead levels found among children in the 1970s. New Jersey is typical of many states in following the Centers for Disease Control and Prevention Centers for Disease Control and Prevention (CDC), agency of the U.S. Public Health Service since 1973, with headquarters in Atlanta; it was established in 1946 as the Communicable Disease Center. (CDC See Control Data, century date change and Back Orifice. CDC - Control Data Corporation ) guideline guideline Medtalk A series of recommendations by a body of experts in a particular discipline. See Cancer screening guidelines, Cardiac profile guidelines, Gatekeeper guidelines, Harvard guidelines, Transfusion guidelines. that requires notification of a health authority when a child's blood lead level is found to exceed 20 [micro]g/dL (CDC, 1991). During the period 1993-1997, approximately 12,000 children were reported to the state health department with one or more instances of blood lead above this level. Local health departments also were notified and were responsible for conducting inspections of the children's homes children's home n → centro de acogida para niños children's home n → foyer m d'accueil (pour enfants) children's home n . If X-ray fluorescence X-ray fluorescence (XRF) is the emission of characteristic "secondary" (or fluorescent) X-rays from a material that has been excited by bombarding with high-energy X-rays or gamma rays. found paint with a lead content of-at least 1.0 milligram milligram /mil·li·gram/ (mg) (mil´i-gram) one thousandth (10-3) of a gram. mil·li·gram n. Abbr. mg A metric unit of mass equal to one thousandth (10-3) of a gram. per square centimeter centimeter (sĕn`tĭmē'tər), abbr. cm, unit of length equal to 0.01 meter, the basic unit of length in the metric system. The centimeter is the unit of length in the cgs system. It is approximately equal to 0. (mg/[cm.sup.2]), an inspector might require the homeowner to remove the 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. paint from all surfaces (window, wall, doorframe) up to 4 feet from the floor. The abatement was then monitored by the local health department. Records of these investigations and abatement approvals were reported to the New Jersey Department of Health and Senior Services (NJDHSS NJDHSS New Jersey Department of Health and Senior Services ) as required by law under the New Jersey Administrative Code 8:51 (1999). Several studies have assessed the effects of home lead abatements on children's blood lead levels (Amitai, Brown, Cosgrove, & Graef, 1991; Farfel & Chisolm, 1990; Staes, Binder binder: see combine. An earlier Microsoft Office workbook file that let users combine related documents from different Office applications. The documents could be viewed, saved, opened, e-mailed and printed as a group. , Copley, Flanders, & Matte, 1994) with conflicting results. Control selection bias, small sample size, different eligibility criteria, and geographic scope all may limit the generalizability of these studies. The present study differs from previous designs in that it used a large statewide database to increase statistical power. Also, to limit possible control selection bias, it used a control group of children living in homes that should have been abated but were not. Subjects and Methods Study Population Records of blood lead tests were obtained from the New Jersey Department of Health and Senior Services for all children who had elevated blood lead (above 20 [micro]g/dL) and for all children who had any blood taken and analyzed for lead at the state laboratory between January 1, 1993, and December 31, 1997. Also obtained were all lead-poisoning environmental abatement records for the period January 1, 1993, to July 6, 1998. Each child who met the following criteria was included in the analysis: * The child had at least two blood lead results, with the first baseline taken between January 1, 1993, and December 31, 1997, showing a baseline blood lead level of [greater than or equal to]30 [micro]g/dL and [less than or equal to]44 [micro]g/dL. * The child was six years of age or younger at the time of the baseline blood lead test. * An abatement had been required for the child's home by the environmental inspector. * The child did not change residence for two months following the baseline inspection, or, if an abatement was required, did not move for two months following completion of the abatement. Table 1 shows the derivation derivation, in grammar: see inflection. of the data set this study analyzed, starting with the original state data. Statistical Analysis Descriptive statistics descriptive statistics see statistics. , multiple regression, and logistic regression were performed using SAS (1) (SAS Institute Inc., Cary, NC, www.sas.com) A software company that specializes in data warehousing and decision support software based on the SAS System. Founded in 1976, SAS is one of the world's largest privately held software companies. See SAS System. software. The purpose was to compare the change in blood lead levels among the children in homes that received abatement to the change among those in homes that did not receive abatement. Indicator variables were used to categorize cat·e·go·rize tr.v. cat·e·go·rized, cat·e·go·riz·ing, cat·e·go·riz·es To put into a category or categories; classify. cat individual years (1993, 1994, etc.). Season was similarly categorized cat·e·go·rize tr.v. cat·e·go·rized, cat·e·go·riz·ing, cat·e·go·riz·es To put into a category or categories; classify. cat : Winter = January-March, Spring = April-June, Summer = July-September, and Fall = October-December. Because of the nonnormal distribution of the data, univariate comparison tests were performed with the Mann-Whitney U test Mann-Whitney U test, n.pr See test, Mann-Whitney U. . Chi-squared tests chi-squared test one of the statistical techniques for determining (1) if there are significant differences between two or more series of frequencies or proportions and (2) whether one series of proportions is significantly different from a control series. were used to compare categorical data categorical data data relating to category such as qualitative data, e.g. dog, cat, female. It may be nominal when a name is used, e.g. location, breed, or ordinal when a range of categories is used, e.g. calf, yearling, cow. (gender, year of baseline blood lead test, and season of baseline blood lead test). On the basis of several previous studies (Bailey et al., 1994; Johnson, Griffith, & McDade, 1995; Brody, Brown, Freeman, Goodman Goodman was a polite term of address, used where Mister (Mr.) would be used today. Compare Goodwife. Goodman refers to:
System of postal-zone codes (zip stands for “zone improvement plan”) introduced in the U.S. in 1963 to improve mail delivery and exploit electronic reading and sorting capabilities. . For multiple regression, a variable indicating abatement completion was forced into the model, and other variables were entered via stepwise stepwise incremental; additional information is added at each step. stepwise multiple regression used when a large number of possible explanatory variables are available and there is difficulty interpreting the partial regression selection, with entry and exit p values of [less than].15. This was done to assess the magnitude of the change in blood lead level associated with a completed abatement while, at the same time, assessing possible confounding confounding when the effects of two, or more, processes on results cannot be separated, the results are said to be confounded, a cause of bias in disease studies. confounding factor by several covariates. After the distribution of time (between baseline and follow-up blood lead levels) was examined and abatement completion was examined, the data were truncated truncated adjective Shortened to those observations where time was [greater than or equal to]70 and [less than or equal to]400 days. This step ensured that the analysis did not extrapolate extrapolate - extrapolation beyond the bounds of the data and restricted the sample size (n = 366). The next step was to check for and remove any outliers--those observations with r-studentized residuals of [greater than]1.97 (t-distributed, 351 degrees of freedom [df], [alpha] = 0.05, two-sided test). Then the final model was selected (n = 352). To evaluate effect modification effect modification Epidemiology An interaction among multiple possible cause-and-effect relationships, where the estimate of the effect of one factor on a disease process depends on other factors in the study , the authors entered interaction terms into the model using stepwise selection with the same entry criteria (p [less than] .15). In the logistic regression (again, the truncated data were used), the probability that a child's blood lead level would decrease by [greater than]4 [micro]g/dL was modeled. This value was chosen because the Clinical Laboratory Improvement Amendments Clinical Laboratory Improvement Amendments (CLIA) of 1988 are United States federal regulatory standards that apply to all clinical laboratory testing performed on humans in the United States, except clinical trials and basic research. (CLIA CLIA Clinical Laboratory Improvement Amendments of 1988 Congressional legislation that promulgated quality assurance practices in clinical labs, and required them to measure performance at each step of the testing process from the beginning to the end-point of a ) Act of 1988 regulates acceptable error as within [+ or -]4 [micro]g/dL when blood lead values are [less than]40 [micro]g/dL (CLIA Act, 1988). Of the baseline blood lead values reported here, 82 percent (n = 488) were [less than]40 [micro]g/dL. A recent study showed that results from several major clinical laboratories serving New Jersey were generally within [+ or -]4 [micro]g/dL (Jobanputra et al., 1998). Farfel and Chisolm (1990) used this same cutoff point Cutoff point The lowest rate of return acceptable on investments. to examine the proportion of children's blood lead levels that declined following abatement. The variable indicating whether the abatement was completed was forced into the model. Other variables were selected via stepwise regression In statistics, stepwise regression includes regression models in which the choice of predictive variables is carried out by an automatic procedure.[1][2][3] , with default entry and exit p values of [less than].10 and [less than].15, respectively To evaluate effect modification, the authors entered interaction terms into the model using stepwise selection with the same entry and exit criteria. Results Several characteristics of the children and homes in which abatements were required and completed differed significantly from those in which abatements were required but not completed (Table 2, Table 3). While baseline blood lead levels did not differ, statistically significant differences were observed for the following characteristics: change in blood lead from baseline to follow up, time between baseline and follow-up, follow-up blood lead level, and year in which the baseline blood lead level was measured. The mean time elapsed e·lapse intr.v. e·lapsed, e·laps·ing, e·laps·es To slip by; pass: Weeks elapsed before we could start renovating. n. between baseline and follow-up was longer in the abatement completion group. This result was largely a design 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 , since inclusion in the abatement completion group required a follow-up blood lead test taken at least two months after abatement, while in the group for which abatement was not completed, all that was needed was a follow-up measurement of blood lead at least two months after baseline. Elapsed time e·lapsed time n. The measured duration of an event. Noun 1. elapsed time - the time that elapses while some event is occurring was therefore longer in the abatement completion group. Among neighborhood characteristics, there were also significant differences between the two groups. The proportion of people receiving public assistance and the proportion of houses built before 1950 differed significantly for children in abated and unabated homes, although the proportion of people receiving public assistance was quite low in both groups. The two groups appeared to differ little with respect to the proportion of people with a high school diploma, population density in the neighborhood, proportion of vacant houses, and median household income. Results of the multiple-linear-regression analysis are shown in Table 4. Because of the near absence of post-abatement blood lead data before 70 days and of data for children in unabated homes after 400 days, the regression model included only children who received follow-up blood lead tests between 70 and 400 days. Statistically significant predictors of a change in blood lead from base line to follow-up were baseline blood lead level, age at baseline, time between baseline and follow-up, baseline measure taken in 1993 or 1994, and baseline measure taken in the winter (January-March). None of the sociodemographic variables and no interaction terms were retained in the model. The regression coefficients Regression coefficient Term yielded by regression analysis that indicates the sensitivity of the dependent variable to a particular independent variable. See: Parameter. regression coefficient for age and time (0.07 and -0.011, respectively) were small because they were recorded in months (6-72) and days (70-400), respectively; nevertheless these variables made significant contributions to the model. Completion of lead abatement in the house was not a statistically significant factor ([beta] = -0.69, 95 percent confidence interval[CI] = -2.50, 1.12) since, on average, abatement reduced a child's blood lead only two percent (0.69/35.5). The overall multiple correlation coefficient Noun 1. multiple correlation coefficient - an estimate of the combined influence of two or more variables on the observed (dependent) variable statistics - a branch of applied mathematics concerned with the collection and interpretation of quantitative data and the ([R.sup.2]) was .21; by comparison, the [R.sup.2] for the model that included outliers (not shown) was .13. Results of the logistic regression modeling a decline of more than 4 [micro]g/dL are shown in Table 5. Significant contributors to such a decline were higher baseline blood lead levels and baseline blood lead measurements taken in the summer (July-September). None of the sociodemographic variables and none of the interaction terms appeared important in the model. Children in homes where abatement was completed were more likely to experience a decline (odds ratio [OR] = 1.4, CI = 0.7, 2.5), but again this effect was not statistically significant. Higher baseline blood lead levels were associated with a greater chance of a decrease in blood lead; for the group with baseline blood lead levels of 35-39 [micro]g/dL, the OR was 1.4 (CI = 1.7, 6.1), and for the group with baseline blood lead levels of 40-44 [micro]g/dL, the OR was 2.6 (CI = 1.3, 5.4). Younger children (OR = 0.9, CI = 0.5, 1.7) and older children (OR = 0.6, CI = 0.3, 1.2) were less likely to experience declines in blood lead of [greater than]4 [micro]g/dL, com pared with children 25-36 months of age. Because the time that elapsed between baseline and follow-up appeared to be so important, the authors conducted an additional analysis in which the blood lead measurements taken closest to one year after baseline were used as the follow-up blood lead measurements for children in both abated and unabated homes. The mean declines in blood lead for children in abated and unabated homes were -10.4 [micro]g/dL (CI= -11.2, -9.6) and -9.4 [micro]g/dL (CI= -11.0, -7.8), respectively, while the times to follow-up (defined as days between baseline and follow-up) were 297.7 (CI = 283.9, 311.5) and 260.7 (CI = 236.7, 284.7). For children in unabated homes, the time increased from 140.2 days in the original analysis to 260.7 days in the subsequent analysis, while in abated homes time decreased from 355.5 to 297.7 days. As expected, the decline in blood lead increased from 7.3 to 9.4 [micro]g/dL for the unabated homes, while for the abated homes it was little changed. Some sharp declines in blood lead, to levels below 20 [micro]g/dL, would be missed if the follow-up blood samples were analyzed at a private laboratory. The authors therefore conducted additional analyses to look for differences between abated and unabated groups in the proportion of follow-up blood samples analyzed in these private laboratories. As shown in Table 6, the proportions of follow-up samples analyzed at private and state laboratories were similar for the two groups. Among follow-up blood lead measurements that were below the baseline blood lead measurement and were analyzed at the state laboratory, 33 percent in the abatement group and 32 percent in the control group were under 20 [micro]g/dL. Discussion While there is general agreement that elimination of exposure is the most important priority for lead-burdened children, previous research evaluating the effectiveness of home lead paint abatements has been inconclusive INCONCLUSIVE. What does not put an end to a thing. Inconclusive presumptions are those which may be overcome by opposing proof; for example, the law presumes that he who possesses personal property is the owner of it, but evidence is allowed to contradict this presumption, and show who is . Amitai, Brown, Cosgrove, and Graef (1991) examined the effect of abatements on children who were under six years of age and had blood lead levels of [greater than or equal]25 [micro]g/dL. Overall, that study found a significant reduction (-2.9 [micro]g/dL, or -8.0 percent) in blood lead levels from baseline to post abatement (taken 49 [+ or -] 8 days after completion of the abatement). During the abatements, there was, however, a temporary increase in blood lead levels of 5.7 [micro]g/dL (15.7 percent) from baseline levels. Although Amitai et al. did not control for chelation Chelation The process by which a molecule encircles and binds to a metal and removes it from tissue. Mentioned in: Heavy Metal Poisoning chelation in their original analysis, an unchelated subset A group of commands or functions that do not include all the capabilities of the original specification. Software or hardware components designed for the subset will also work with the original. (n = 59) of the study population showed a significant decrease (10.2 [micro]g/dL, or -28.6 percent) in blood lead levels from pre-abatement levels at long-term follow-up, taken 250 [+ or -] 14 days after abatement. This decline is substantially larger than the short-term effect described above, but may simply be a function of elapsed time. There was no control group of children from homes where abatement had not been completed and only a limited sample size for the assessment of long-term effects. Farfel and Chisolm (1990) did not analyze the general effect of all abatements on blood lead levels; instead, they analyzed the differences in the effects of two abatement methods on dust lead and blood lead in children with blood lead levels [greater than]29 [micro]g/dL. They compared a traditional abatement, the typical abatement done in Baltimore at that time as required by law (n = 53), to a modified abatement in which city crews made substantial efforts to clean up after abatement, dispose of debris off site, and repaint Re`paint´ v. t. 1. To paint anew or again; as, to repaint a house; to repaint the ground of a picture. s> Verb 1. (n = 18); the modified abatement also excluded open-flame treatment and sanding. The traditional group showed acute increases in levels of lead dust on both floors and windowsills as well as increases in blood lead levels at both one-month and six-month intervals. Overall, 48 percent of children in homes undergoing traditional abatement had increases in blood lead of 5 [micro]g/dL or more. At six months, following abatements of both types, Farfel and Chisolm found that levels of lead dust were close to or greater than pre-abatement levels, suggesting that the abatements were not long-term solutions. Staes, Binder, Copley, Flanders, & Matte (1994) assessed the effectiveness of lead abatements in reducing blood lead levels 10 to 14 months after diagnosis. Their study incorporated a control group of children whose homes did not require abatement. Baseline blood lead levels were comparable in the two groups, averaging 35 [micro]g/dL. There was a borderline-significant difference between groups in the reduction of blood lead--23 percent for remediated homes and 12 percent for nonremediated homes. Abatement effects of similar size were seen when a multiple regression model was used (-13 percent) and when a model based on generalized gen·er·al·ized adj. 1. Involving an entire organ, as when an epileptic seizure involves all parts of the brain. 2. Not specifically adapted to a particular environment or function; not specialized. 3. estimating equations was used (-16 percent). Staes et al. suggested that although children in homes that had under-gone abatements showed a greater decline in blood lead levels than did children in homes that had not undergone abatement, this effect might have been influenced by the blood lead level at baseline. A difficulty of their study was that the control homes, which were judged not to require abatement, may not have been comparable to the abated homes. The authors of the present study also saw decreases in the mean blood lead level of children in homes that had undergone abatement (-10.1 [micro]g/dL), and those decreases were significantly different from decreases among children living in homes not under-going abatement, (-7.3 [micro]g/dL), but an important confounder con·found tr.v. con·found·ed, con·found·ing, con·founds 1. To cause to become confused or perplexed. See Synonyms at puzzle. 2. , time between baseline and follow-up, differed substantially between the two groups (Table 2). When this and other confounders were controlled in a multiple-regression model, abatement was associated with only a small change in follow-up blood lead levels (-0.69 [micro]g/dL [CI = -2.50, 1.12])--only a two percent drop from baseline values. Differences in time from baseline to follow-up account for a substantial fraction of the difference in blood lead decline between children in homes where abatement was completed and homes where it was not. Other confounders, such as baseline blood lead value, season, and age, also were important in predicting a change in blood lead level, which is consistent with effects found in prior work (Johnson et al., 1995; Staes et al., 1994). The residual effect of abatement on blood lead, as estimated in this analysis, is substantially smaller than the 16 to 33 percent reductions in blood lead estimated for dust clean-up approaches (Charney, Farfel, Jackson, & Kessler, 1983; Rhoads et al., 1999). Other differences between abated and unabated homes also could have affected the results of this study. Among such differences might be the exclusion of results from blood lead samples analyzed at private laboratories if those results were below 20 [micro]g/dL, as well as entry error, parental household cleaning, chelation, and social characteristics of the families. Still, although the administrative databases used for this study may have contained some errors, it is unlikely that such errors were disproportionate dis·pro·por·tion·ate adj. Out of proportion, as in size, shape, or amount. dis  pro·por between the two groups.
Because the study population was restricted to children with baseline
blood lead levels under 45 [micro]g/dL, the likelihood of chelation in
the study population was reduced. Succimer, the chelating agent chelating agenta substance which combines with a metallic ion to produce an inert chelate, e.g. ethylenediamine tetra-acetic acid, penicillamine. most commonly used when blood lead levels are below 45 [micro]g/dL, is labeled for use only above 44 [micro]g/dL. It is unlikely that more than a modest proportion of children in the study population were chelated che·late adj. Zoology Having chelae or resembling a chela. n. Chemistry A chemical compound in the form of a heterocyclic ring, containing a metal ion attached by coordinate bonds to at least two nonmetal ions. , and there appears little reason to posit that chelated children were more likely to be in one group than the other. (The distribution of baseline blood lead levels was almost identical in the two groups). To the extent that unmeasured social variables such as tenant-landlord relationships and compliance with environmental recommendations and ordinances may have differed between the two groups, the authors believe that children in homes receiving abatements were also more likely to belong to better-integrated families and to have a more favorable fa·vor·a·ble adj. 1. Advantageous; helpful: favorable winds. 2. Encouraging; propitious: a favorable diagnosis. 3. prognosis prognosis /prog·no·sis/ (prog-no´sis) a forecast of the probable course and outcome of a disorder.prognos´tic prog·no·sis n. pl. prog·no·ses 1. than those in homes not receiving abatements. Thus, such differences might be expected to exaggerate, rather than to obscure, the effect of abatement. Conclusions The analysis reported here suggests that lead paint abatements in New Jersey and in many jurisdictions with similar regulations are of limited efficacy in reducing children's blood lead levels from an initially reported range of 30 to 44 [micro]g/dL. It is heartening heart·en tr.v. heart·ened, heart·en·ing, heart·ens To give strength, courage, or hope to; encourage. See Synonyms at encourage. Adj. 1. that blood lead levels did fall substantially in both groups of children, probably reflecting reduced hand-to-mouth activity as the children grew older, parent education as a result of clinical and public-health encounters, and, almost certainly, some regression to the mean. Nevertheless, the failure of abatements to produce a more striking reduction relative to the children whose homes did not receive abatement seems to indicate that between the two groups, the difference in the extent of continuing exposure was small. It is likely that lead-contaminated dust in abated and nonabated homes contributed to continuing exposure of resident children. Because of the study design limitations discussed above, these results must be regarded as tentative. They demonstrate the need for more carefully designed studies of the efficacy of required abatements as currently implemented in U.S. communities. If confirmed, the findings may imply the need for altered regulations that promote more specific, effective, and timely abatement approaches, at least for children whose lead exposure sources are thought to include paint ingestion ingestion /in·ges·tion/ (-chun) the taking of food, drugs, etc., into the body by mouth. in·ges·tion n. 1. The act of taking food and drink into the body by the mouth. 2. , or alternative strategies such as repeated dust reductions. Improved regulations requiring more comprehensive and stringent inspection, abatement, and cleanup procedures went into effect in New Jersey on June 7,1999 (NJ. Administrative Code, 1999), creating a specific rationale for mounting a more careful study of their effects. Of assistance in the design of such a study will be the new requirement that all results from blood lead testing in New Jersey children be reported to NJDHSS Acknowledgements: This work was partially supported by a grant from the National Institute of Environmental Health Sciences The National Institute of Environmental Health Sciences (NIEHS) is one of 27 Institutes and Centers of the National Institutes of Health (NIH),which is a component of the Department of Health and Human Services (DHHS). The Director of the NIEHS is Dr. David A. Schwartz. (NIEHS NIEHS National Institute of Environmental Health Sciences (NIH, DHHS) ) (Grant Number ES05022-09); by an NIEHS Center Grant; by a grant from the Public Health Service and the Centers for Disease Control and Prevention (CDC) (Grant Number H64/CCH205081); and by an agreement with the Association of Teachers of Preventive Medicine preventive medicine, branch of medicine dealing with the prevention of disease and the maintenance of good health practices. Until recently preventive medicine was largely the domain of the U.S. , CDC, and the Agency for Toxic Substances and Disease Registry The United States Agency for Toxic Substances and Disease Registry, (ATSDR) is an agency for the U.S. Department of Health and Human Services that is directed by a congressional mandate to perform specific functions concerning the effect on public health of hazardous (Cooperative Agreement Number TS259-13/13). The views expressed in this article are those of the authors and do not necessarily reflect the views of the agencies with which the authors are associated. Corresponding Author: David Q. Rich, M.P.H., Harvard School of Public Health The Harvard School of Public Health is (colloquially, HSPH) is one of the professional graduate schools of Harvard University. Located in Longwood Area of the Boston, Massachusetts neighborhood of Mission Hill, next to Harvard Medical School and Cambridge, Massachusetts, , Environmental Epidemiology epidemiology, field of medicine concerned with the study of epidemics, outbreaks of disease that affect large numbers of people. Epidemiologists, using sophisticated statistical analyses, field investigations, and complex laboratory techniques, investigate the cause Program, 665 Huntington Avenue, Bldg. 1, Room 1414, Boston, MA 02115. E-mail: <drich@hsph.harvard.edu>. REFERENCES Adgate, J.L., Buckley, T.J., Chow, J.C., Lioy, P.J., Rhoads, G.G., Watson, J.G., & Wills, R.D. (1998). Chemical mass balance source apportionment The process by which legislative seats are distributed among units entitled to representation; determination of the number of representatives that a state, county, or other subdivision may send to a legislative body. The U.S. of lead in house dust. Environmental Science and Technology, 32(1), 108-114. Adgate, J.L., Lioy, P.J., & Rhoads, G.G. (1998). The use of isotope isotope (ī`sətōp), in chemistry and physics, one of two or more atoms having the same atomic number but differing in atomic weight and mass number. The concept of isotope was introduced by F. ratios to apportion ap·por·tion tr.v. ap·por·tioned, ap·por·tion·ing, ap·por·tions To divide and assign according to a plan; allot: "The tendency persists to apportion blame as suits the circumstances" sources of lead in Jersey City, New Jersey, house dust wipe samples. Science of the Total Environment, 221, 171-180. Amitai, Y., Brown, M.J., Cosgrove, E., & Graef, J.W. (1991). Residential deleading: Effects on the blood lead levels of lead-poisoned children. Pediatrics, 88(5), 893-897. Bailey, D.J., Flegal, K.M., Gunter, E.W., Kramer, R.A., Matte, T.M., Paschal, D.C., & Pirkle, J.L. (1994). Blood lead levels in the U.S. population: Phase 1 of the Third National Health and Nutrition Examination Survey (NHANES III NHANES III Third National Health & Nutrition Examination Survey Public health A population-based survey conducted by the National Center for Health Statistics, designed to assess the health and nutritional status of the noninstitutionalized Americans , 1988 to 1991). Journal of the American Medical Association JAMA: The Journal of the American Medical Association is an international peer-reviewed general medical journal, published 48 times per year by the American Medical Association. JAMA is the most widely circulated medical journal in the world. , 272, 277-283. Brody, A.J., Brown, M.J., Freeman, J., Goodman, D.C., & Sargent, J.D. (1994). Poisoned landscapes: The epidemiology of environmental lead exposure in Massachusetts children 1990-1991. Social Science & Medicine, 39(6), 757-766. Centers for Disease Control and Prevention. (1991). Preventing lead poisoning in young children. DHHS DHHS Department of Health & Human Services (US government) DHHS Dana Hills High School (Dana Point, California) DHHS Deaf and Hard of Hearing Services DHHS Deaf and Hard of Hearing Services publication no. (PHS/CDC) 1992-633-627. Atlanta: U.S. Department of Health and Human Services Noun 1. Department of Health and Human Services - the United States federal department that administers all federal programs dealing with health and welfare; created in 1979 Health and Human Services, HHS . Charney, E., Farfel, M., Jackson, D., & Kessler, B. (1983). Childhood lead poisoning: A controlled trial controlled trial Clinical research A clinical study in which one group of participants receives an experimental drug while the other receives either a placebo or an approved–'gold standard' therapy. See Blinding, Double-blinded. of the effect of dust-control measures on blood lead levels. New England Journal of Medicine The New England Journal of Medicine (New Engl J Med or NEJM) is an English-language peer-reviewed medical journal published by the Massachusetts Medical Society. It is one of the most popular and widely-read peer-reviewed general medical journals in the world. , 309(18), 1089-93. Clinical Laboratory Improvement Amendments Act, 42 C.F.R. [ss] 440 (1988). Farfel, M.R., & Chisolm, J.J., Jr. (1990). Health and environmental outcomes of traditional and modified practices for abatement of residential lead-based paint. American Journal of Public Health The American Journal of Public Health (AJPH) is a peer reviewed monthly journal of the American Public Health Association (APHA). The Journal also regularly publishes authoritative editorials and commentaries and serves as a forum for the analysis of health policy. , 80,1240-1245. Farfel, M.R., & Chisolm, J.J., Jr. (1991). An evaluation of experimental practices for abatement of residential lead-based paint: Report on a pilot project. Environmental Research, 55, 199-212. Farfel, M.R., Chisolm, J.J., Jr., & Rohde, C.A. (1994). The longer-term effectiveness of residential lead paint abatement. Environmental Research, 66, 217-221. Jobanputra, N.K., Buckler, G., Cody, R.P., Gochfeld, M., Jones, R., Matte, T.M., Rich, D.Q., & Rhoads, G.G. (1998). Accuracy and reproducibility of blood lead measurements in commercial laboratories. Archives of Pediatrics & Adolescent Medicine adolescent medicine n. The branch of medicine concerned with the treatment of youth between 13 and 21 years of age. Also called ephebiatrics, hebiatrics. , 152, 548-553. Johnson, D.L., Griffith, D., & McDade, K. (1995). Seasonal variation in paediatric Adj. 1. paediatric - of or relating to the medical care of children; "pediatric dentist" pediatric blood lead levels in Syracuse, New York
Syracuse (IPA: , United States of America UNITED STATES OF AMERICA. The name of this country. The United States, now thirty-one in number, are Alabama, Arkansas, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Mississippi, Missouri, New Hampshire, . Environmental Geochemistry geochemistry, study of the chemical changes on the earth. More specifically, it is the study of the absolute and relative abundances of chemical elements in the minerals, soils, ores, rocks, water, and atmosphere of the earth and the distribution and movement of & Health, 17, 1-8. Lanphear, B.P., Ashley, P., Bornschein, R.L., Clickner, R.P., Dietz, B., Dixon, S., Farfel, M., Galke, W., Jacobs, D.E., Mahaffey, K.R., Matte, T.D., Rabinowitz, M., Rogers, J., Rohde, C., Schwartz, J., & Succop, P. (1998). The contribution of lead-contaminated house dust and residential soil to children's blood lead levels. Environmental Research, 79(1), 51-68. N.J. Administrative Code title 31, [ss] 8-51 (New Jersey Registry, Public Health Council Chapter XIII of State Sanitary Code Noun 1. sanitary code - set of standards established and enforced by government for health requirements as in plumbing etc health code code, codification - a set of rules or principles or laws (especially written ones) : Childhood Lead Poisoning. Adopted, Repeal The Annulment or abrogation of a previously existing statute by the enactment of a later law that revokes the former law. The revocation of the law can either be done through an express repeal , and New Rules) (1999). Rhoads, G.G., Adgate, J., Buckley, T.J., Ettinger, A.S., Goldman, K.D., Lioy, P.J., & Weisel, C.P. (1999). The effect of dust lead control on blood lead in toddlers: A randomized ran·dom·ize tr.v. ran·dom·ized, ran·dom·iz·ing, ran·dom·iz·es To make random in arrangement, especially in order to control the variables in an experiment. trial. Pediatrics, 103, 551-555. Sargent, J.D., Bailey, A., Blake, M., Dalton, M., & Simon, P. (1997). Census tract A census tract, census area, or census district is a particular community defined for the purpose of taking a census. Usually these coincide with the limits of cities, towns or other administrative areas and several tracts commonly exist within a county. analysis of lead exposure in Rhode Island Rhode Island, island, United States Rhode Island, island, 15 mi (24 km) long and 5 mi (8 km) wide, S R.I., at the entrance to Narragansett Bay. It is the largest island in the state, with steep cliffs and excellent beaches. children. Environmental Research, 74, 159-168. Staes, C., Binder, S., Copley, C.G., Flanders, D., & Matte, T. (1994). Retrospective study retrospective study, a study in which a search is made for a relationship between one phenomenon or condition and another that occurred in the past (e.g. of the impact of lead-based paint hazard remediation on children's blood lead levels in St. Louis, Missouri. American Journal of Epidemiology, 139(10), 1016-1026.
Three-Step Derviation of the Study Sample
Sample Size Deletions
Step 1. Initial Blood
Lead Data
12,957
6,085
6,872
Step 2. Initial Environ-
mental Report Data
23,499
7,570
3,584
12,345
Step 3. Merging of
Environmental
Reports Data and
Blood Lead Data
6,872
1,482
1,081
3,559
262
122
264
102
Sample Size Description
Step 1. Initial Blood
Lead Data
12,957 Individual children [2]
Children whose data set did
not contain at least 2
observations
6,872 Children's data sets eligible
for merging with environmental
report data
Step 2. Initial Environ-
mental Report Data
23,499 Environmental reports
Reports not complete
Not the 1st home of the child, or
the child moved shortly after
1st investigation
12,345 Environmental reports eligible for
for merging with blood lead data
Step 3. Merging of
Environmental
Reports Data and
Blood Lead Data
6,872 Possible matches from 6.872 children
and 12,345 environmental reports
No matching environmental report
Baseline blood lead level was not
identified
Child did not have a baseline blood
lead level between 30 and 44 [micro]g/
dL; the baseline blood lead test was
not taken between 01/01/93 and
12/31/97; or an appropriate follow-up
blood lead test was not taken either 2
months after the completion of the
abatement or 2 months after the
baseline blood lead test
No census data were available for the
zip code; the child was older than six
years at baseline; the abatement
completion data came before the
baseline blood lead date; or abatement
was not required
Time between baseline and follow-up
was [less than]70 or [greater than]400
days
264 Observations for which abatement was
required and completed
102 Observations for which abatement was
required but not completed
(a.)Includes 2,748 children with blood lead values of [less than]20 [micro]g/dL obtained at the Department of Health laboratory. Because the analyses were done at the New Jersey State laboratory, the results were entered into the NJDHSS database.
Individual and Neighborhood Characteristics Related to Completion of
Required Abatements
Abatement Required
and Completed (n = 370)
Variable Mean
Individual characteristics
Baseline blood lead level 35.5
Follow-up blood lead level [**] 25.4
Change in blood lead level [**] -10.1
Time-between baseline and 359.3
follow-up (days) [**]
Age in months at baseline 30.5
Neighborhood characteristics
Proportion with public assistance [*] 0.049
Proportion of homes 0.49
built before 1950 [*]
Proportion of people with a 0.63
high school diploma
Population density 14,669
(persons/[mile.sup.2])
Proportion of houses vacant 0.084
Median household income ($) 27,608
Variable (95% Cl)
Individual characteristics
Baseline blood lead level (35.1, 35.9)
Follow-up blood lead level [**] (24.4, 26.3)
Change in blood lead level [**] (-11.0, -9.1)
Time-between baseline and (333.8, 384.8)
follow-up (days) [**]
Age in months at baseline (29.2, 31.9)
Neighborhood characteristics
Proportion with public assistance [*] (0.047, 0.052)
Proportion of homes (0.48, 0.50)
built before 1950 [*]
Proportion of people with a (0.62, 0.64)
high school diploma
Population density (13,879, 15,459)
(persons/[mile.sup.2])
Proportion of houses vacant (0.077, 0.090)
Median household income ($) (26,847, 28,368)
Abatement Required
but Not Completed (n = 118)
Variable Mean
Individual characteristics
Baseline blood lead level 35.1
Follow-up blood lead level [**] 27.8
Change in blood lead level [**] -7.3
Time-between baseline and 140.2
follow-up (days) [**]
Age in months at baseline 30.3
Neighborhood characteristics
Proportion with public assistance [*] 0.054
Proportion of homes 0.52
built before 1950 [*]
Proportion of people with a 0.61
high school diploma
Population density 15,209
(persons/[mile.sup.2])
Proportion of houses vacant 0.088
Median household income ($) 26,772
Variable (95% Cl)
Individual characteristics
Baseline blood lead level (34.4, 35.7)
Follow-up blood lead level [**] (26.3, 29.3)
Change in blood lead level [**] (-8.7, -5.8)
Time-between baseline and (122.3, 158.2)
follow-up (days) [**]
Age in months at baseline (27.7, 33.0)
Neighborhood characteristics
Proportion with public assistance [*] (0.050 0.059)
Proportion of homes (0.50, 0.54)
built before 1950 [*]
Proportion of people with a (0.59, 0.63)
high school diploma
Population density (13,875, 16,543)
(persons/[mile.sup.2])
Proportion of houses vacant (0.076, 0.100)
Median household income ($) (25,275, 28,269)
(*.)Maan Whitney U test, p [less than] .05
(**.)Mann Whitney U test, p [less than] .01
Selected Variable Distributions,
by Abatement Completion Group
Abatement Required
Variable and Completed (n = 370)
Gender
Female 44%
Male 56%
Season of baseline blood lead test
Spring 24%
Summer 48%
Fall 15%
Winter 13%
Year of baseline blood
lead test [***]
1993 38%
1994 29%
1995 19%
1996 9%
1997 5%
Abatement Required
Variable but Not Completed (n = 118)
Gender
Female 43%
Male 57%
Season of baseline blood lead test
Spring 19%
Summer 46%
Fall 16%
Winter 19%
Year of baseline blood
lead test [***]
1993 19%
1994 15%
1995 12%
1996 19%
1997 35%
(***.)p [less than] .001, Chi-squared test.
Modeling the Change in Blood Lead from Baseline to Follow-up--Multiple
Regression
Independent Variables Parameter Estimate 95% Confidence Interval
([beta])
Log of baseline blood -40.25 -53.93, -26.57
lead level
Age in months at baseline 0.07 0.02, 0.12
Year of baseline blood
lead level
1993 3.50 1.45, 5.55
1994 2.34 0.19, 4.49
1995 reference
1996 1.31 -1.26, 3.88
1997 2.19 -0.35, 4.71
Season of baseline blood
lead test
Winter 3.10 0.80, 5.40
Spring reference
Summer -1.49 -3.25, 0.27
Fall 1.78 -0.44, 4.00
Time between baseline and -0.011 -0.020, -0.002
follow-up (days)
Abatement completed?
Yes -0.69 -2.50, 1.12
No reference
Note: a = 352. [R.sup.2] = .21. Intercept = 51.42 (29.85, 72.99).
Dependent variable = change in blood lead level from baseline to
follow-up.
Modeling the Probability of a Decrease of
[greater than]4 [micro]g/dL in Blood Lead from
baseline to Follow-up--Logistic Regression
Variable Odds Ratio
Log of baseline blood lead level
([micro]g/dL)
30-31 1.0
32-34 reference
35-39 3.2
40-44 2.6
Age in months at baseline
[less than]25 0.9
25-36 reference
[greater than]36 0.6
Year of baseline blood lead test
1993-1996 reference
1997 1.3
Season of baseline blood lead test
Winter 0.7
Spring reference
Summer 1.8
Fall 0.8
Time between baseline and follow-up (days) 1.002
Abatement completed?
Yes 1.4
No reference
Variable 95% Confidence Interval
Log of baseline blood lead level
([micro]g/dL)
30-31 0.5, 1.9
32-34 1.7, 6.1
35-39 1.3, 5.4
40-44 1.3, 1.7
Age in months at baseline
[less than]25 0.5, 1.7
25-36
[greater than]36 0.3, 1.2
Year of baseline blood lead test
1993-1996
1997 0.6, 2.7
Season of baseline blood lead test
Winter 0.3, 1.4
Spring
Summer 1.0, 3.4
Fall 0.4, 1.7
Time between baseline and follow-up (days) 0.999, 1.005
Abatement completed?
Yes 0.7, 2.5
No
Note: --2 log likelihood (Chi-square) = 39.9 (p [less than] .001).
Modeling: 1 = decrease by [greater than] 4 [micro]g/dL (n = 257);
0 = no such decrease (n = 109).
Percentages of Samples Analyzed at State and Private Laboratories, by
Abatement Completion Category
Abatement Category Laboratory Type
Private State
Abatement completed
Baseline 73.9% (n = 187) 26.1% (n = 66)
Follow-up 65.2% (n = 165) 34.8% (n = 88)
Abatement not completed
Baseline 74.7% (n = 74) 25.3% (n = 25)
Follow-up 69.7% (n = 69) 30.3% (n = 30)
|
|
||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion