title: Reliability of concentrations of organophosphate pesticide metabolites in serial urine specimens from pregnancy in the Generation R Study.
abstract: The widespread use of organophosphate (OP) pesticides has resulted in ubiquitous exposure in humans, primarily through their diet. Exposure to OP pesticides may have adverse health effects, including neurobehavioral deficits in children. The optimal design of new studies requires data on the reliability of urinary measures of exposure. In the present study, urinary concentrations of six dialkyl phosphate (DAP) metabolites, the main urinary metabolites of OP pesticides, were determined in 120 pregnant women participating in the Generation R Study in Rotterdam. Intra-class correlation coefficients (ICCs) across serial urine specimens taken at <18, 18-25, and >25 weeks of pregnancy were determined to assess reliability. Geometric mean total DAP metabolite concentrations were 229 (GSD 2.2), 240 (GSD 2.1), and 224 (GSD 2.2) nmol/g creatinine across the three periods of gestation. Metabolite concentrations from the serial urine specimens in general correlated moderately. The ICCs for the six DAP metabolites ranged from 0.14 to 0.38 (0.30 for total DAPs), indicating weak to moderate reliability. Although the DAP metabolite levels observed in this study are slightly higher and slightly more correlated than in previous studies, the low to moderate reliability indicates a high degree of within-person variability, which presents challenges for designing well-powered epidemiological studies.
authors.affiliation: Department of Risk Analysis for Products in Development, TNO, Zeist, The Netherlands.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Spaan
authors.affiliation: Department of Risk Analysis for Products in Development, TNO, Zeist, The Netherlands.
authors.forename: Anjoeka
authors.initials: A
authors.lastname: Pronk
authors.affiliation: Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Holger M
authors.initials: HM
authors.lastname: Koch
authors.affiliation: Departments of Public Health Sciences and Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Jusko
authors.affiliation: 1] The Generation R Study Group, Erasmus Medical Center, Rotterdam, The Netherlands [2] Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands [3] Department of Pediatrics, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Vincent W V
authors.initials: VW
authors.lastname: Jaddoe
authors.affiliation: Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Shaw
authors.affiliation: 1] The Generation R Study Group, Erasmus Medical Center, Rotterdam, The Netherlands [2] Department of Child and Adolescent Psychiatry, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Henning M
authors.initials: HM
authors.lastname: Tiemeier
authors.affiliation: 1] The Generation R Study Group, Erasmus Medical Center, Rotterdam, The Netherlands [2] Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Department of Urban Environment and Safety, TNO, Utrecht, The Netherlands.
authors.forename: Frank H
authors.initials: FH
authors.lastname: Pierik
authors.affiliation: Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, North Carolina, USA.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Longnecker
mesh_terms: D000328:Adult; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000652:urine*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D018811:Maternal Exposure / Q000706:statistics & numerical data*; D009426:Netherlands; D010755:Organophosphates / Q000652:urine*; D010575:Pesticides / Q000652:urine*; D011247:Pregnancy / Q000652:urine*; D012044:Regression Analysis; D015203:Reproducibility of Results
chemical_list: D004785:Environmental Pollutants; D010755:Organophosphates; D010575:Pesticides