title: Associations between self-reported pest treatments and pesticide concentrations in carpet dust.
abstract: BACKGROUND
  Recent meta-analyses demonstrate an association between self-reported residential pesticide use and childhood leukemia risk. Self-reports may suffer from recall bias and provide information only on broad pesticide categories. We compared parental self-reported home and garden pest treatments to pesticides measured in carpet dust.
  
  
  METHODS
  Parents of 277 children with leukemia and 306 controls in Northern and Central California (2001-2007) were asked about insect and weed treatments during the previous year. Carpet dust samples were analyzed for 47 pesticides. We present results for the 7 insecticides (carbaryl, propoxur, chlorpyrifos, diazinon, cyfluthrin, cypermethrin, permethrin), 5 herbicides (2,4-dichlorophenoxyacetic acid [2,4-D], chlorthal, dicamba, mecoprop, simazine), and 1 synergist (piperonyl butoxide) that were present in home and garden products during the study period and were detected in ≥25% of carpet dust samples. We constructed linear regression models for the relative change in pesticide concentrations associated with self-reported treatment of pest types in cases and controls separately and combined, adjusting for demographics, housing characteristics, and nearby agricultural pesticide applications.
  
  
  RESULTS
  Several self-reported treatments were associated with pesticide concentrations in dust. For example, households with flea/tick treatments had 2.3 (95% Confidence Interval [CI]: 1.4, 3.7) times higher permethrin concentrations than households not reporting this treatment. Households reporting treatment for ants/cockroaches had 2.5 (95% CI: 1.5, 4.2) times higher cypermethrin levels than households not reporting this treatment. Weed treatment by a household member was associated with 1.9 (1.4, 2.6), 2.2 (1.6, 3.1), and 2.8 (2.1, 3.7) times higher dust concentrations of dicamba, mecoprop, and 2,4-D, respectively. Weed treatments by professional applicators were null/inversely associated with herbicide concentrations in dust. Associations were generally similar between cases and controls and were consistent with pesticide active ingredients in these products during the study time period.
  
  
  CONCLUSIONS
  Consistency between self-reported pest treatments, concentrations in dust, and pesticides in products lends credibility to the exposure assessment methods and suggests that differential recall by case-control status is minimal.
authors.affiliation: Yale School of Public Health, Department of Environmental Health Sciences, 60 College St., New Haven, CT, 06510, USA. nicole.deziel@yale.edu.|Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr., Rockville, MD, 20850, USA. nicole.deziel@yale.edu.
authors.forename: Nicole C
authors.initials: NC
authors.lastname: Deziel
authors.affiliation: Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr., Rockville, MD, 20850, USA. coltj@mail.nih.gov.
authors.forename: Joanne S
authors.initials: JS
authors.lastname: Colt
authors.affiliation: Outcomes Research Branch, Applied Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr., Rockville, MD, 20850, USA. erin.kent@nih.gov.
authors.forename: Erin E
authors.initials: EE
authors.lastname: Kent
authors.affiliation: School of Public Health, University of California, 50 University Hall, Berkeley, CA, 94720, USA. gunier@berkeley.edu.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Gunier
authors.affiliation: Cancer Prevention Institute of California, 2201 Walnut Ave., Fremont, CA, 94538, USA. Peggy.Reynolds@cpic.org.|Department of Health Research and Policy, Stanford University School of Medicine, 291 Campus Dr., Stanford, CA, 94305, USA. Peggy.Reynolds@cpic.org.
authors.forename: Peggy
authors.initials: P
authors.lastname: Reynolds
authors.affiliation: Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr., Rockville, MD, 20850, USA. benjamin.booth@nih.gov.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Booth
authors.affiliation: School of Public Health, University of California, 50 University Hall, Berkeley, CA, 94720, USA. cmetayer@berkeley.edu.
authors.forename: Catherine
authors.initials: C
authors.lastname: Metayer
authors.affiliation: Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr., Rockville, MD, 20850, USA. wardm@mail.nih.gov.
authors.forename: Mary H
authors.initials: MH
authors.lastname: Ward
mesh_terms: D000293:Adolescent; D002140:California / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004391:Dust / Q000032:analysis*; D004781:Environmental Exposure; D005260:Female; D005430:Floors and Floorcoverings; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007938:Leukemia / Q000139:chemically induced / Q000453:epidemiology*; D008297:Male; D010571:Pest Control / Q000706:statistics & numerical data; D010573:Pesticide Residues / Q000032:analysis*; D015995:Prevalence; D018570:Risk Assessment; D057566:Self Report
chemical_list: D004391:Dust; D010573:Pesticide Residues