title: Urinary p-nitrophenol as a biomarker of household exposure to methyl parathion.
abstract: Methyl parathion (MP) is an organophosphate pesticide illegally applied to the interiors of many hundreds of homes throughout the United States by unlicensed pesticide applicators. Public health authorities developed a protocol for investigating contaminated homes and classifying their need for public health interventions. This protocol included environmental screening for MP contamination and 1-day biomonitoring (a.m. and p.m. spot urine samples) of household members for p-nitrophenol (PNP), a metabolite of MP. The variability of urinary PNP excretion under these exposure conditions was unknown. We collected a.m. and p.m. spot urine samples for 7 consecutive days from 75 individuals, who were members of 20 MP-contaminated households in the greater Chicago, Illinois, area, and analyzed them for PNP. We also assessed the ability of the 1-day sampling protocol to correctly classify exposed individuals and households according to their need for public health interventions, assuming that 1 week of sampling (14 urinary PNPs) represented their true exposure condition. The coefficient of variation of log urinary PNPs for individuals over the course of 7 days of a.m. and p.m. sampling averaged about 15%. Adjusting for urinary excretion of creatinine improved reproducibility of urinary PNPs among children but not among adults. The 1-day protocol correctly classified true risk category in 92% of individuals and 85% of households. The data contained in this study can be used to refine what is already a reasonable and effective approach to identifying MP-exposed households and determining the appropriate public health intervention.
authors.affiliation: Great Lakes Center for Occupational and Environmental Safety and Health, University of Illinois School of Public Health, Chicago, Illinois 60612, USA. dhryhorc@uic.edu
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Hryhorczuk
authors.forename: Mike
authors.initials: M
authors.lastname: Moomey
authors.forename: Ann
authors.initials: A
authors.lastname: Burton
authors.forename: Ken
authors.initials: K
authors.lastname: Runkle
authors.forename: Edwin
authors.initials: E
authors.lastname: Chen
authors.forename: Tiffanie
authors.initials: T
authors.lastname: Saxer
authors.forename: Jennifer
authors.initials: J
authors.lastname: Slightom
authors.forename: John
authors.initials: J
authors.lastname: Dimos
authors.forename: Ken
authors.initials: K
authors.lastname: McCann
authors.forename: Dana
authors.initials: D
authors.lastname: Barr
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000493:pharmacokinetics; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D006798:Housing; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007300:Insect Control; D007306:Insecticides / Q000009:adverse effects* / Q000032:analysis / Q000493:pharmacokinetics; D008297:Male; D008743:Methyl Parathion / Q000009:adverse effects* / Q000032:analysis / Q000493:pharmacokinetics; D009596:Nitrophenols / Q000652:urine*; D011634:Public Health; D018570:Risk Assessment; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D007306:Insecticides; D009596:Nitrophenols; D008743:Methyl Parathion; D003404:Creatinine; C024836:4-nitrophenol