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. 2013 Feb 1:66:145-150.
doi: 10.1016/j.atmosenv.2012.06.087.

Presence of organophosphorus pesticide oxygen analogs in air samples

Affiliations

Presence of organophosphorus pesticide oxygen analogs in air samples

Jenna L Armstrong et al. Atmos Environ (1994). .

Abstract

A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and laboratory experiments were used to examine artificial formation of chlorpyrifos-oxon using OSHA Versatile Sampling (OVS) tubes as recommended by NIOSH method 5600. Additionally, we compared expected chlorpyrifos-oxon attributable to artificial transformation to observed chlorpyrifos-oxon in field samples from a 2008 Washington State Department of Health air monitoring study using non-parametric statistical methods. The amount of artificially transformed oxon was then modeled to determine the amount of oxon present in the environment. Toxicity equivalency factors (TEFs) for chlorpyrifos-oxon were used to calculate chlorpyrifos-equivalent air concentrations. The results demonstrate that the NIOSH-recommended sampling matrix (OVS tubes with XAD-2 resin) was found to artificially transform up to 30% of chlorpyrifos to chlorpyrifos-oxon, with higher percentages at lower concentrations (< 30 ng/m3) typical of ambient or residential levels. Overall, the 2008 study data had significantly greater oxon than expected by artificial transformation, but the exact amount of environmental oxon in air remains difficult to quantify with the current sampling method. Failure to conduct laboratory analysis for chlorpyrifos-oxon may result in underestimation of total pesticide concentration when using XAD-2 resin matrices for occupational or residential sampling. Alternative methods that can accurately measure both OP pesticides and their oxygen analogs should be used for air sampling, and a toxicity equivalent factor approach should be used to determine potential health risks from exposures.

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Figures

Figure 1
Figure 1
% Artificial Transformation to Oxon by Log Mass per Unit Volume of Total Chlorpyrifos
Figure 2
Figure 2
Mann Whitney U-test comparing observed vs. expected % chlorpyrifos-oxon at concentration tertiles; * = p value ≤ 0.05.

References

    1. Arcury T, Quandt S, Barr D, Hoppin J, McCauley L, Grzywacz J, Robson M. Farmworker exposure to pesticides: methodologic issues for the collection of comparable data. Environ Health Perspect. 2006;114:923–928. - PMC - PubMed
    1. ASTM. Standard Practice for Sampling and Selection of Analytical Techniques for Pesticides and Polychlorinated Biphenyls in Air. ASTM D4861-11. 2011 Annual Book of ASTM Standards: Volume 11.07, Atmospheric Analysis. (ASTM formerly known as American Society for Testing and Materials) 2011
    1. Aston L, Seiber J. Fate of summertime airborne organophosphate pesticide residues in the Sierra Nevada Mountains. J. Environ. Qual. 1997;26:1483–1492.
    1. Bavcon Kralj M, Franko M, Trebš P. Photodegradation of organophosphorus insecticides – investigations of products and their toxicity using gas chromatography–mass spectrometry and AChE-thermal lens spectrometric bioassay. Chemosphere. 2007;67:99–107. - PubMed
    1. CARB. Report for the Application and Ambient Air Monitoring of Chlorpyrifos (and oxon analogue) in Tulare Country During Spring/Summer 1996. Sacramento, CA: California Air Resources Board; 1998. Apr 7,

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