title: Concentrations of dialkyl phosphate metabolites of organophosphorus pesticides in the U.S. population.
abstract: We report population-based concentrations, stratified by age, sex, and racial/ethnic groups, of dialkyl phosphate (DAP) metabolites of multiple organophosphorus pesticides. We measured dimethylphosphate (DMP), dimethylthiophosphate (DMTP), dimethyldithiophosphate (DMDTP), diethylphosphate (DEP), diethylthiophosphate (DETP), and diethyldithiophosphate (DEDTP) concentrations in 1,949 urine samples collected in U.S. residents 6-59 years of age during 1999 and 2000 as a part of the ongoing National Health and Nutrition Examination Survey (NHANES). We detected each DAP metabolite in more than 50% of the samples, with DEP being detected most frequently (71%) at a limit of detection of 0.2 microg/L. The geometric means for the metabolites detected in more than 60% of the samples were 1.85 microg/L for DMTP and 1.04 microg/L for DEP. The 95th percentiles for each metabolite were DMP, 13 microg/L; DMTP, 46 microg/L; DMDTP, 19 micro g/L; DEP, 13 microg/L; DETP, 2.2 microg/L; and DEDTP, 0.87 microg/L. We determined the molar sums of the dimethyl-containing and diethyl-containing metabolites; their geometric mean concentrations were 49.4 and 10.5 nmol/L, respectively, and their 95th percentiles were 583 and 108 nmol/L, respectively. These data are also presented as creatinine-adjusted concentrations. Multivariate analyses showed concentrations of DAPs in children 6-11 years of age that were consistently significantly higher than in adults and often higher than in adolescents. Although the concentrations between sexes and among racial/ethnic groups varied, no significant differences were observed. These data will be important in evaluating the impact of organophosphorus pesticide exposure in the U.S. population and the effectiveness of regulatory actions.
authors.affiliation: National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. dbarr@cdc.gov
authors.forename: Dana B
authors.initials: DB
authors.lastname: Barr
authors.forename: Roberto
authors.initials: R
authors.lastname: Bravo
authors.forename: Gayanga
authors.initials: G
authors.lastname: Weerasekera
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Caltabiano
authors.forename: Ralph D
authors.initials: RD
authors.lastname: Whitehead
authors.forename: Anders O
authors.initials: AO
authors.lastname: Olsson
authors.forename: Samuel P
authors.initials: SP
authors.lastname: Caudill
authors.forename: Susan E
authors.initials: SE
authors.lastname: Schober
authors.forename: James L
authors.initials: JL
authors.lastname: Pirkle
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Sampson
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Jackson
authors.forename: Larry L
authors.initials: LL
authors.lastname: Needham
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D003404:Creatinine / Q000032:analysis; D003430:Cross-Sectional Studies; D005006:Ethnicity; D005260:Female; D006801:Humans; D007306:Insecticides / Q000378:metabolism* / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D009946:Organothiophosphorus Compounds; D044469:Racial Groups; D012016:Reference Values; D012737:Sex Factors; D014018:Tissue Distribution; D014481:United States
chemical_list: D007306:Insecticides; D009946:Organothiophosphorus Compounds; D003404:Creatinine