Cancer Incidence and Metolachlor Use in the Agricultural Health Study: An Update

Details

• Personal Author:
  Alavanja MDR ; Beane Freeman LE ; Bertke SJ ; Hines CJ ; Hoppin JA ; Lubin JH ; Rusiecki JA ; Sandler DP ; Silver, Sharon R.
• Description:
  Background: Metolachlor, a widely used herbicide, has been classified as a possible human carcinogen (Group C) by the U.S. Environmental Protection Agency based on an increase in liver neoplasms in female rats. Epidemiologic studies of the health effects of metolachlor have been limited. Methods: The Agricultural Health Study (AHS) is a prospective cohort study including licensed private and commercial pesticide applicators in Iowa and North Carolina enrolled 1993-7. In this update, we extended follow-up for cancer incidence through 2010 (NC) and 2011 (IA). We used Poisson regression to evaluate relations between two metrics of metolachlor use (lifetime days, intensity-weighted lifetime days) and cancer incidence. Results: Of the 49,616 applicators, 53% reported ever using metolachlor. We saw no association between metolachlor use and incidence of all cancers combined (n=5701 with a 5-year lag) or most site-specific cancers. However, for liver cancer, trends for both lifetime and intensityweighted lifetime days of metolachor use were positive and statistically significant with an unexposed reference group; in analyses restricted to exposed workers, elevations observed at higher categories of use were not statistically significant. A similar pattern was observed for follicular-cell lymphoma, but no other lymphoma subtypes. Discussion: This update of pesticide applicators in the Agricultural Health Study is the first occupational epidemiology assessment to report positive associations between metolachlor use and liver cancer in humans and echoes observation of increased liver neoplasms in some animal studies. However, our findings for both liver cancer and follicular-cell lymphoma warrant further follow-up to better differentiate effects of metolachlor use from other factors. [Description provided by NIOSH]
• Subjects:
  Agriculture Cohort Studies Epidemiology Herbicides Neoplasms Occupational Health Safety
• Keywords:
  Agricultural Workers Cancer Rates Cohort Studies Metolachlor
• Publisher:
  Society for Epidemiologic Research
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Colorado ; Ohio ; OSHA Region 5 ; OSHA Region 8 ; Utah
• 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
• NIOSHTIC Number:
  nn:20066356
• Citation:
  48th Annual Society for Epidemiologic Research (SER) Meeting, June 16-19, 2015, Denver, Colorado. Clearfield, UT: Society for Epidemiologic Research, 2015 Jun; :112
• Contact Point Address:
  Sharon R. Silver, National Institute for Occupational Safety and Health, Cincinnati, OH
• CAS Registry Number:
  Metolachlor (CAS RN 51218-45-2)
• Federal Fiscal Year:
  2015
• Peer Reviewed:
  False
• Source Full Name:
  48th Annual Society for Epidemiologic Research (SER) Meeting, June 16-19, 2015, Denver, Colorado
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:0f531833d75f8d9afd0d804601a8365035a06b9670e06d584f02175ec7d4f21c5753a4d7f856188eb9705e2deeb8420a128dd8c7da69cb9295b3fbf53d34ee46
• Download URL:
  https://stacks.cdc.gov/view/cdc/212822/cdc_212822_DS1.pdf
• File Type:
  [PDF - 808.83 KB ]