Biomonitoring of persons exposed to insecticides used in residences

Pesticides used indoors inevitably result in some unintentional and unavoid able exposures of residents, Measured dosages of residents are well below t oxic levels. Exposures (mug/kg-day) are substantially less and occur over a longer time than suggested by unvalidated estimates derived from previous extreme, conservative default assumptions based solely on environmental res idues, Human chlorpyrifos exposures were monitored following three differen t types of applications: fogger, broadcast, and crack-and-crevice. Persiste nce of total residue on carpet was substantially greater than the persisten ce of transferable residue (mug/cm(2)). Low-level (mug/kg) exposures of fam ily members persisted for periods of weeks to a month after pesticide use, Although few children who resided with their parents in pest-protected home s have been monitored, they eliminated more biomarker than their parents on a kg body weight-day basis when absorbed dosages (mug/kg-day) were derived from spot urine specimens corrected for volume by an age-specific creatini ne correction. Ultimately environmental residues may become useful elements of predictive residential exposure models, but their potential contributio n to indirect exposure assessments must include careful determination of re sidue availability for contact transfer to clothing or skin and biological validation. When environmental data from monitoring studies reported here w ere used to estimate residential exposure according to Residential Exposure Assessment Standard Operating Procedures (SAP meeting, 1997), measured exp osures were substantially less than assessments. Experimental and situation al monitoring of exposed persons is essential for meaningful and responsibl e predictive resident exposure model building. (C) 2001 British Occupationa l Hygiene Society. Published by Elsevier Science Ltd. All rights reserved.