The 100 percent difference.For many IAQ IAQ Indoor Air Quality
IAQ Investment Administration Qualification
IAQ Infrequently Asked Questions
IAQ Internal Air Quality
IAQ Inuit Art Quarterly
IAQ Illinois Air Quality laboratory methods, there are currently no published standards. Notably, no standard method exists for the analysis of fungal fungal /fun·gal/ (fun´g'l) fungous; pertaining to fungi.
fun·gal or fun·gous
1. Of, relating to, resembling, or characteristic of a fungus.
2. spores in indoor air, and there is a diverse range of analytical approaches and statistical analyses of data. Laboratories typically analyze anywhere from 15 percent to 100 percent of the sample from spore trap cassettes, and, depending on the nature of the sample, the percentage analyzed can have a significant effect on the final results.
Aerotech P & K conducted a study to identify significant differences, if any, between two common analytical approaches used for spore trap cassettes. Fifty-five Zefon Air-O-Cell[R] cassette samples were analyzed via both the 15 percent and the 100 percent counting methods, and the results were compared. These samples, which were taken in various indoor and outdoor environments, were analyzed by degreed de·greed
Having or requiring an academic degree: a degreed biologist; a degreed profession. analysts with at least two years of experience. The results were compiled, and several interesting observations were made when the data were compared.
In outdoor air samples, the data show relatively little influence from method selection. In sharp contrast, air samples from indoor environments often contain aggregate fungal conidia co·nid·i·a
Plural of conidium. and other multi-spore structures; the data show significant differences between the two methods.
When compared with a reading based on 100 percent of the sample, the 15 percent technique failed to detect Stachybotrys in 9 percent of the samples. The 100 percent counting method detected at least one Stachybotrys spore in five of the samples analyzed, whereas the 15 percent method detected zero Stachybotrys in the entire project. With Stachybotrys and other specific moisture indicator genera genera, in taxonomy: see classification. commonly being a target of interest in both analysis and remediation efforts, it would be beneficial to use a 100 percent counting method.
In addition, 18 percent of the samples were skewed skewed
curve of a usually unimodal distribution with one tail drawn out more than the other and the median will lie above or below the mean.
skewed Epidemiology adjective Referring to an asymmetrical distribution of a population or of data because of heterogeneous deposition of spores. When the 15 percent method detected spores in samples with only a few chains or clumps clump
1. A clustered mass; a lump: clumps of soil.
2. A thick grouping, as of trees or bushes.
3. A heavy dull sound; a thud.
v. of spores, the extrapolation (mathematics, algorithm) extrapolation - A mathematical procedure which estimates values of a function for certain desired inputs given values for known inputs.
If the desired input is outside the range of the known values this is called extrapolation, if it is inside then calculations made a huge impact on the final results. For example, when a chain of five Cladosporium spores is detected in the 15 percent count, the extrapolation is 467 Cladosporium per cubic meter Noun 1. cubic meter - a metric unit of volume or capacity equal to 1000 liters
cubic metre, kiloliter, kilolitre
metric capacity unit - a capacity unit defined in metric terms . The same number of spores counted with the 100 percent method is calculated at only 67 Cladosporium per cubic meter. Conversely con·verse 1
intr.v. con·versed, con·vers·ing, con·vers·es
1. To engage in a spoken exchange of thoughts, ideas, or feelings; talk. See Synonyms at speak.
2. , if there are a few scattered Scattered
Used for listed equity securities. Unconcentrated buy or sell interest. chains throughout the sample trace, but only one of these chains is detected in the 15 percent technique, the calculated results will be much higher (and more accurate) with the 100 percent counting method.
Samples with low spore concentrations showed variation in results as well. For example, the 15 percent counting method missed five or more genera in 25 percent of the samples. The samples had between one and 25 spores for each of the missed genera counted. These numbers could easily mean the difference between a zero total spore count by the 15 percent method and a significant total spore count by the 100 percent method.
In 9 percent of the samples, the 15 percent counting method failed to detect spores in concentrations less than or equal to 227 per cubic meter. Again, these concentrations are low, but the reporting of such results occurred only with the 100 percent counting method, and the counts may have included Stachybotrys or other key genera.
Selecting a laboratory for IAQ analysis may be a difficult choice, especially with the number of laboratories available. In the absence of a standard method for spore trap analysis, it is advisable to look at the benefits of using a laboratory employing the 100 percent counting method. Heterogeneous spore deposition on an indoor slide, low spore concentrations, and the difference between a 100 percent counting method and a 15 percent counting method can make all the difference in the world when accuracy is of the utmost importance.
Technical Briefs presents short but information-packed items on a variety of field-related topics in environmental health. The information this month is provided courtesy of two sister corporations that specialize in environmental health laboratory testing: Precision Analytical Laboratories, Inc., and Aerotech Laboratories, Inc., both based in Phoenix, Arizona Phoenix /ˈfiːˌnɪks/ (English: Phoenix, Navajo: Hoozdo, lit. "the place is hot", Western Apache: Fiinigis) is the capital and the most populous city of the U.S. . Readers interested in receiving additional information about Precision Analytical Laboratories and Aerotech Laboratories, including information about how to subscribe to Verb 1. subscribe to - receive or obtain regularly; "We take the Times every day"
buy, purchase - obtain by purchase; acquire by means of a financial transaction; "The family purchased a new car"; "The conglomerate acquired a new company"; a free "Tech Tips" listserv for environmental health professionals, can contact Aerotech Laboratories/Precision Analytical Laboratories at 2020 West Lone Cactus Drive, Phoenix, AZ 85027. Aerotech and Precision also can be reached by phone at (800) 651-4802 or (623) 780-4800; by fax at (623) 780-7695; or on the Internet at http://www.aerotechlabs.com or http://www.palabs.com.