title: Have regulatory efforts to reduce organophosphorus insecticide exposures been effective?
abstract: BACKGROUND
  The Food Quality Protection Act (FQPA) was signed into law in 1996 to strengthen the regulation of pesticide tolerances in food. Organophosphorus (OP) insecticides were the first group of pesticides reviewed by the U.S. Environmental Protection Agency (EPA) under the new law.
  
  
  OBJECTIVE
  Our goal was to determine whether urinary concentrations of dialkylphosphate (DAP) metabolites of OP pesticides declined between the National Health and Nutrition Examination Survey (NHANES) III and NHANES 1999-2004.
  
  
  METHODS
  Using mass spectrometry-based methods, we analyzed urine samples from a nationally representative sample of 2,874 adults 20-59 years of age in NHANES 1999-2004 and samples from a non-nationally representative sample of 197 adult participants for NHANES III (1988-1994) for six common DAP metabolites of OP pesticides.
  
  
  RESULTS
  Median urinary DAP concentrations decreased by more than half between NHANES III and NHANES 2003-2004. Reductions of about 50%-90% were also observed for 95th percentile concentrations of five of the six metabolites. Frequencies of detection (FODs) decreased in all six metabolites (< 50% reduction). On average, median and 95th percentile concentrations and FODs showed a larger decrease in diethylphosphate metabolites than dimethylphosphate metabolites.
  
  
  CONCLUSIONS
  Human exposure to OP insecticides as assessed by urinary DAP concentrations has decreased since the implementation of the FQPA, although we cannot be certain that U.S. EPA actions in response to the FQPA directly caused the decrease in DAP concentrations.
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322 , USA.
authors.forename: Alison L
authors.initials: AL
authors.lastname: Clune
authors.forename: P Barry
authors.initials: PB
authors.lastname: Ryan
authors.forename: Dana Boyd
authors.initials: DB
authors.lastname: Barr
mesh_terms: D000328:Adult; D002849:Chromatography, Gas; D004781:Environmental Exposure / Q000032:analysis / Q000331:legislation & jurisprudence*; D004784:Environmental Monitoring; D058735:Environmental Policy; D005260:Female; D033161:Government Regulation; D006801:Humans; D007306:Insecticides / Q000378:metabolism / Q000652:urine*; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D009943:Organophosphorus Compounds / Q000378:metabolism / Q000652:urine*; D053719:Tandem Mass Spectrometry; D013997:Time Factors; D014481:United States; D055815:Young Adult
chemical_list: D007306:Insecticides; D009943:Organophosphorus Compounds