Impact of pesticide exposure misclassification on estimates of relative risks in the Agricultural Health Study

Details

• Personal Author:
  Alavanja MCR ; Beane Freeman L ; Blair, Austin ; Coble J ; Dosemeci, Mustafa ; Hines CJ ; Hoar Zahm S ; Hoppin JA ; Kamel F ; Knott C ; Lubin JH ; Lynch CF ; Purdue MP ; Sandler DP ; Thomas K
• Description:
  Background: The Agricultural Health Study (AHS) is a prospective study of licensed pesticide applicators and their spouses in Iowa and North Carolina. We evaluate the impact of occupational pesticide exposure misclassification on relative risks using data from the cohort and the AHS Pesticide Exposure Study (AHS/PES). Methods: We assessed the impact of exposure misclassification on relative risks using the range of correlation coefficients observed between measured post-application urinary levels of 2,4-dichlorophenoxyacetic acid (2,4-D) and a chlorpyrifos metabolite and exposure estimates based on an algorithm from 83 AHS pesticide applications. Results: Correlations between urinary levels of 2,4-D and a chlorpyrifos metabolite and algorithm estimated intensity scores were about 0.4 for 2,4-D (n=64), 0.8 for liquid chlorpyrifos (n=4) and 0.6 for granular chlorpyrifos (n=12). Correlations of urinary levels with kilograms of active ingredient used, duration of application, or number of acres treated were lower and ranged from -0.36 to 0.19. These findings indicate that a priori expert-derived algorithm scores were more closely related to measured urinary levels than individual exposure determinants evaluated here. Estimates of potential bias in relative risks based on the correlations from the AHS/PES indicate that non-differential misclassification of exposure using the algorithm would bias estimates towards the null, but less than that from individual exposure determinants. Conclusions: Although correlations between algorithm scores and urinary levels were quite good (ie, correlations between 0.4 and 0.8), exposure misclassification would still bias relative risk estimates in the AHS towards the null and diminish study power. [Description provided by NIOSH]
• Subjects:
  Acids Agriculture Energy Metabolism Environmental Monitoring Family Herbicides Insecticides Occupational Health Risk Assessment Risk Factors Safety Urine

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• Keywords:
  Agricultural-chemicals Agricultural-workers Chlorophenoxy-herbicides Exposure-assessment Families Mathematical-models Metabolites Pesticides Pesticides-and-agricultural-chemicals Risk-analysis Risk-factors Urinalysis

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• ISSN:
  1351-0711
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Iowa ; Maryland ; North Carolina ; Ohio ; OSHA Region 3 ; OSHA Region 4 ; OSHA Region 5 ; OSHA Region 7
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DSHEFS - Division of Surveillance, Hazard Evaluations, and Field Studies
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  68
• Issue:
  7
• NIOSHTIC Number:
  nn:20038641
• Citation:
  Occup Environ Med 2011 Jul; 68(7):537-541
• Contact Point Address:
  Aaron Blair, National Cancer Institute, Executive Plaza South, Room 8008, Bethesda, MD 20892, USA
• Email:
  blaira@mail.nih.gov
• CAS Registry Number:
  (2,4-Dichlorophenoxy)acetic acid (CAS RN 94-75-7) ; Chlorpyrifos (CAS RN 2921-88-2)
• Federal Fiscal Year:
  2011
• NORA Priority Area:
  Agriculture, Forestry and Fishing
• Peer Reviewed:
  True
• Source Full Name:
  Occupational and Environmental Medicine
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:0a6c595a97f047e8504581bffd6c0f1560d6a7a52be99671aacf1cecacae0ee69172728bed182aeaf8bb753347b18b5eacaa0fa1b2186bd79114d54928dd4df1
• Download URL:
  https://stacks.cdc.gov/view/cdc/192285/cdc_192285_DS1.pdf
• File Type:
  [PDF - 258.31 KB ]