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MOVEMENT AND DEPOSITION OF TWO ORGANOPHOSPHORUS PESTICIDES WITHIN A RESIDENCE AFTER INTERIOR AND EXTERIOR APPLICATIONS
Citation:
Lewis, R G., C. R. Fortune, F. T. Blanchard, AND D. E. Camann. MOVEMENT AND DEPOSITION OF TWO ORGANOPHOSPHORUS PESTICIDES WITHIN A RESIDENCE AFTER INTERIOR AND EXTERIOR APPLICATIONS. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION 51(3):339-351, (2001).
Impact/Purpose:
The goal of this task is to contribute to a better understanding of human exposure to pesticides, especially for small children by developing methods to characterize sources and pathways in and around the residential environment. We will support the science behind FQPA and assist the Office of Pesticide Programs (OPP) in the development of guidelines for the assessment of residential exposure to pesticides. Specific research objectives include: (i) to evaluate and develop methods for measuring pesticides in air using passive/diffusive samplers. Assess and refine devices for the collection of surface transferable pesticide residues and to establish transfer efficiencies; (ii) to develop and apply analytical methods for new and emerging pesticides using both gas and liquid chromatographic methods in support of the National Exposure Research Laboratory's (NERL) Human Exposure Measurement Project; and, (iii) to conduct pilot studies investigating chiral chromatographic methods.
Description:
Post-application temporal and spatial distributions of two organophosphorus pesticides, diazinon and chlorpyrifos, were monitored after homeowner applications for indoor and outdoor insect control. Samples were taken before and up to 12 days after treatments in the family room, kitchen and child's bedroom of indoor air, vacuumable carpet dust, carpet dislodgeable residues, deposits on bare floors, table tops and dinnerware, surrogate food, and residues on children's hands and toys. Results from the study demonstrate the nature and magnitude of translocation of pesticides from the areas of application to surfaces accessible for human contact and permit comparisons of potential exposures via respiration and dermal contact/oral ingestion. Potential indoor inhalation exposures were estimated to be as high as 0.5 ug/kg/d for diazinon applied indoors and 0.05 ug/kg/d for chlorpyrifos applied to the outside perimeter of the house. While ingestion of carpet dust at the rate of 100 mg/d would have added a maximum of only about 0.01 ug/kg/d to the daily dose, residues found on the children's hands suggest that repeated mouthing could have contributed as much as 1 to 1.5 ug/kg/d. These estimates are below the Environmental Protection Agency (EPA) reference dose for chlorpyrifos, but exceed those for diazinon.
This work has been funded wholly or in part by the U.S. Environmental Protection Agency under contract 68-D5-0049 to ManTech Environmental Technology, Inc. It has been subjected to Agency review and approved for publication.