title: Poultry and livestock exposure and cancer risk among farmers in the agricultural health study.
abstract: OBJECTIVE
  The purpose of this study is to evaluate cancer risk associated with raising animals as commodities, which is associated with a variety of exposures, such as infectious agents and endotoxins.
  
  
  METHODS
  Information was available for 49,884 male farmers in the Agricultural Health Study, who reported livestock and poultry production at enrollment (1993-1997). Cancer incidence data were obtained through annual linkage to state registries. Using Poisson regression analyses, we evaluated whether the number and type of animals raised on the farm impacted cancer risk.
  
  
  RESULTS
  Overall, 31,848 (63.8%) male farmers reported raising any animals. Lung cancer risk decreased with increasing number of livestock on the farm (p trend = 0.04) and with raising poultry (Relative Risk (RR) = 0.6; 95% confidence interval (CI): 0.4-0.97). Raising poultry was associated with an increased risk of colon cancer (RR = 1.4; 95% CI: 0.99-2.0) with further increased with larger flocks (p trend = 0.02). Risk of non-Hodgkin lymphoma was also elevated in those who raised poultry (RR = 1.6; 95% CI: 1.0-2.4), but there was no evidence of increased risk with larger flocks (p trend = 0.5). Raising sheep was associated with a significantly increased risk of multiple myeloma (RR = 4.9; 95% CI: 2.4-12.0). Performing veterinary services increased the risk of Hodgkin lymphoma (RR = 12.2; 95% CI: 1.6-96.3).
  
  
  CONCLUSIONS
  We observed an inverse association between raising poultry and livestock and lung cancer risk and some evidence of increased risk of specific lymphohematopoietic malignancies with specific types of animals and performing veterinary services. Further research into associations between raising animals and cancer risk should focus on identification of etiologic agents.
authors.affiliation: Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. freemala@mail.nih.gov
authors.forename: Laura E
authors.initials: LE
authors.lastname: Beane Freeman
authors.forename: Anneclaire J
authors.initials: AJ
authors.lastname: Deroos
authors.forename: Stella
authors.initials: S
authors.lastname: Koutros
authors.forename: Aaron
authors.initials: A
authors.lastname: Blair
authors.forename: Mary H
authors.initials: MH
authors.lastname: Ward
authors.forename: Michael
authors.initials: M
authors.lastname: Alavanja
authors.forename: Jane A
authors.initials: JA
authors.lastname: Hoppin
mesh_terms: D000328:Adult; D000368:Aged; D000382:Agricultural Workers' Diseases / Q000139:chemically induced / Q000453:epidemiology*; D016573:Agrochemicals / Q000506:poisoning; D000395:Air Pollutants, Occupational / Q000506:poisoning; D000822:Animal Husbandry; D000818:Animals; D015331:Cohort Studies; D006801:Humans; D015994:Incidence; D058751:Livestock; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D016273:Occupational Exposure / Q000009:adverse effects / Q000706:statistics & numerical data; D011200:Poultry; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
chemical_list: D016573:Agrochemicals; D000395:Air Pollutants, Occupational