If chemical exposures are a significant cause of cancer, as some environmentalists say, you’d expect that individuals who apply pesticides for a living would have higher cancer rates. But a recent study conducted by the U.K.-based Health and Safety Laboratory indicates, that’s not the case—at least not for pesticide workers. The study looked at mortality among 59,085 male and 3,875 female commercial pesticide applicators, and found 1,628 deaths within this group between the years of 1987-2005.
They found no evidence that these workers suffered from any more cancer than the general population. Instead, they found less cancer. Here’s the summary:
All cause[s of] mortality was substantially lower among the pesticide users than in the general population (standardised mortality ratio (SMR) 0.58, 95% CI 0.55-0.61), as was mortality for a number of the major disease groups:
All cancers combined (SMR 0.72, 95% CI 0.66-0.78),
- Cancers of the lip, oral cavity and pharynx (SMR 0.18, 95% CI 0.07-0.48),
- Cancers of the digestive organs (SMR 0.78, 95% CI 0.68-0.90),
- Cancers of the respiratory system (SMR 0.55, 95% CI 0.46-0.65),
- Non-malignant diseases of the nervous system and sense organs (SMR 0.39, 95% CI 0.27-0.57),
- Non-malignant diseases of the circulatory system (SMR 0.58, 95% CI 0.520.63)
- Non-malignant diseases of the respiratory system (SMR 0.39, 95% CI 0.310.49)
- Non-malignant diseases of the digestive system (SMR 0.24, 95% CI 0.18-0.32)
Does this mean that working in the pesticide industry reduces your cancer risks? Not really, but it does raise questions about activist claims about cancer risks posed by pesticides, particularly when they suggest that consumers, who have much lower exposures than workers, face substantial risks.
The authors also do note that there “some evidence of excess deaths from multiple myeloma in men and women, and possibly also from testicular cancer.” This is the type of stuff greens might jump on while ignoring the key findings of this study. However, the authors explain that these involved “relatively small numbers of deaths” with “mostly wide confidence intervals and statistical non-significance,” which means “these need to be interpreted with caution.” “With the limited data available, it was not possible to investigate whether these were linked with particular jobs, working practices or pesticides,” the authors also noted.
In other words, there’s little evidence that pesticides are a significant cause of cancer even among some of the most exposed populations. There is plenty evidence, on the other hand, that these products serve important public health and agricultural values.