Cancer incidence of 2,4-D production workers.
Despite showing no evidence of carcinogenicity in laboratory animals, the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been associated with non-Hodgkin lymphoma (NHL) in some human epidemiology studies, albeit inconsistently. We matched an existing cohort of 2,4-D manufacturing employees with cancer registries in three US states resulting in 244 cancers compared to 276 expected cases. The Standardized Incidence Ratio (SIR) for the 14 NHL cases was 1.36 (95% Confidence Interval (CI) 0.74-2.29). Risk estimates were higher in the upper cumulative exposure and duration subgroups, yet not statistically significant. There were no clear patterns of NHL risk with period of hire and histology subtypes. Statistically significant results were observed for prostate cancer (SIR = 0.74, 95% CI 0.57-0.94), and "other respiratory" cancers (SIR = 3.79, 95% CI 1.22-8.84; 4 of 5 cases were mesotheliomas). Overall, we observed fewer cancer cases than expected, and a non statistically significant increase in the number of NHL cases.
The Dow Chemical Company, Epidemiology, 1803 Building, Midland, MI 48674, USA. cjburns@dow.com
Carol
C
Burns
Kenneth
K
Bodner
Gerard
G
Swaen
James
J
Collins
Kathy
K
Beard
Marcia
M
Lee
D015084:2,4-Dichlorophenoxyacetic Acid / Q000633:toxicity*; D000328:Adult; D000368:Aged; D000395:Air Pollutants, Occupational / Q000633:toxicity*; D002617:Chemical Industry; D015331:Cohort Studies; D006540:Herbicides / Q000633:toxicity*; D006801:Humans; D015994:Incidence; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology*; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D016273:Occupational Exposure; D055815:Young Adult
D000395:Air Pollutants, Occupational; D006540:Herbicides; D015084:2,4-Dichlorophenoxyacetic Acid