title: Passive Sampling for Indoor and Outdoor Exposures to Chlorpyrifos, Azinphos-Methyl, and Oxygen Analogs in a Rural Agricultural Community.
abstract: Recent studies have highlighted the increased potency of oxygen analogs of organophosphorus pesticides. These pesticides and oxygen analogs have previously been identified in the atmosphere following spray applications in the states of California and Washington.
  
  
  
  We used two passive sampling methods to measure levels of the ollowing organophosphorus pesticides: chlorpyrifos, azinphos-methyl, and their oxygen analogs at 14 farmworker and 9 non-farmworker households in an agricultural region of central Washington State in 2011.
  
  
  
  The passive methods included polyurethane foam passive air samplers deployed outdoors and indoors and polypropylene deposition plates deployed indoors. We collected cumulative monthly samples during the pesticide application seasons and during the winter season as a control.
  
  
  
  Monthly outdoor air concentrations ranged from 9.2 to 199 ng/m3for chlorpyrifos, 0.03 to 20 ng/m3for chlorpyrifos-oxon, < LOD (limit of detection) to 7.3 ng/m3for azinphos-methyl, and < LOD to 0.8 ng/m3for azinphos-methyl-oxon. Samples from proximal households (≤ 250 m) had significantly higher outdoor air concentrations of chlorpyrifos, chlorpyrifos-oxon, and azinphos-methyl than did samples from nonproximal households (p≤ 0.02). Overall, indoor air concentrations were lower than outdoors. For example, all outdoor air samples for chlorpyrifos and 97% of samples for azinphos-methyl were > LOD. Indoors, only 78% of air samples for chlorpyrifos and 35% of samples for azinphos-methyl were > LOD. Samples from farmworker households had higher indoor air concentrations of both pesticides than did samples from non-farmworker households. Mean indoor and outdoor air concentration ratios for chlorpyrifos and azinphos-methyl were 0.17 and 0.44, respectively.
  
  
  
  We identified higher levels in air and on surfaces at both proximal and farmworker households. Our findings further confirm the presence of pesticides and their oxygen analogs in air and highlight their potential for infiltration of indoor living environments. Citation: Gibbs JL, Yost MG, Negrete M, Fenske RA. 2017. Passive sampling for indoor and outdoor exposures to chlorpyrifos, azinphos-methyl, and oxygen analogs in a rural agricultural community. Environ Health Perspect 125:333-341; http://dx.doi.org/10.1289/EHP425.
authors: Department of Occupational and Environmental Health, University of Iowa College of Public Health, Iowa City, Iowa, USA.
authors: Jenna L
authors: JL
authors: Gibbs
authors: Michael G
authors: MG
authors: Yost
authors: Maria
authors: M
authors: Negrete
authors: Richard A
authors: RA
authors: Fenske
mesh_terms: D000383:Agriculture; D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis; D001272:Atmosphere; D001387:Azinphosmethyl / Q000032:analysis*; D002140:California; D004390:Chlorpyrifos / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis / Q000706:statistics & numerical data*; D004784:Environmental Monitoring; D006801:Humans; D007306:Insecticides / Q000032:analysis*; D010100:Oxygen; D012424:Rural Population; D014861:Washington
chemical_list: D000393:Air Pollutants; D007306:Insecticides; D001387:Azinphosmethyl; D004390:Chlorpyrifos; D010100:Oxygen