Background: Diesel exhaust is a known lung carcinogen. Farmers use a variety of dieselized equipment and thus may be at increased risk of lung cancer, but farm exposures such as endotoxins may also be protective for lung cancer.
Objectives: We evaluated the relative risk of incident lung cancer, including histological subtype, from enrollment (1993–1997) to 2010–2011 in relation to farm equipment use in the Agricultural Health Study (AHS), a prospective cohort study of pesticide applicators and spouses in Iowa and North Carolina, USA.
Methods: Farm equipment use was reported by 21,273 farmers and 29,840 spouses. Rate ratios (RRs) were estimated separately for farmers and spouses with Poisson regression models adjusted for smoking and other confounders. We conducted stratified analyses by exposure to animals or stored grain, a surrogate for endotoxin exposure.
Results: Daily diesel tractor use (vs. no use) was positively associated with lung cancer in farmers (RR = 1.48; 95% CI: 0.87, 2.50; 35 exposed, 32 unexposed cases), particularly adenocarcinoma (RR = 3.39; 95% CI: 1.23, 9.33; 12 exposed, 7 unexposed cases). The association of adenocarcinoma with daily (vs. low/no) use of diesel tractors was stronger for farmers with no animal or stored grain exposures (RR = 6.23; 95% CI: 2.25, 17.25; 5 exposed, 18 unexposed cases) than among farmers with these exposures (RR = 1.19; 95% CI: 0.51, 2.79; 7 exposed, 27 unexposed cases) (p-interaction = 0.05).
Conclusions: This study provides preliminary evidence of an increased risk of lung adenocarcinoma among daily drivers of diesel tractors and suggests that exposure to endotoxins may modify the impact of diesel exposure on lung cancer risk. Confirmation of these findings with more exposed cases and more detailed exposure information is warranted.
1INSERM, UMR 1086 Cancers et Préventions, Caen, France; 2Université de Caen, Normandie, Caen, France; 3Centre de Lutte Contre le Cancer François Baclesse, Caen, France; 4Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Rockville, Maryland, USA; 5Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle, North Carolina, USA; 6Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
Recommended Citation:
Séverine Tual,1,2,et al. Use of Dieselized Farm Equipment and Incident Lung Cancer: Findings from the Agricultural Health Study Cohort[J]. Environmental Health Perspectives,2016-01-01,Volume 124(Issue 5):611