red farm tractor spraying pesticide on crop field

US Agricultural Health Study Links Glyphosate to Leukemia

A recent update of a very large study of diseases of pesticide applicators identified a possible association between glyphosate use and acute myeloid leukemia (AML). The study, called the Agricultural Health Study (AHS), “found some evidence of a possible association between glyphosate use and AML,” warning that “Given the prevalence of use of this herbicide worldwide, expeditious efforts to replicate these findings are warranted”. The increase risk of AML was over 2-fold higher in highest exposed applicators compared with the never exposed applicators.

November 17, 2017 | Source: Sustainable Pulse | by

A recent update of a very large study of diseases of pesticide applicators identified a possible association between glyphosate use and acute myeloid leukemia (AML). The study, called the Agricultural Health Study (AHS), “found some evidence of a possible association between glyphosate use and AML,” warning that “Given the prevalence of use of this herbicide worldwide, expeditious efforts to replicate these findings are warranted”. The increase risk of AML was over 2-fold higher in highest exposed applicators compared with the never exposed applicators.

The possible link with leukemia should be very concerning to the public and particularly to pesticide applicators, because AML is a very serious fast-growing cancer, with a five-year survival rate of only 27% (see NIH stats for details).

Moreover, although the results did not reach statistical significance at the 95% confidence interval (CI), it is likely that had a 90% confidence level been used, the elevated cancer risk for AML would have been significant. A 90% CI is more appropriate for pesticides like glyphosate—it is more like conducting a one-tailed statistical test at a significance level of 0.1, instead of a two-tailed test at 0.05. A one-tailed test (or using a 90% CI) is more appropriate for a toxic chemical like glyphosate that can be expected to have only a harmful effect, and not also a healthful one. Two-tailed tests are used for substances like pharmaceutical agents, where both beneficial and potential harmful effects could be expected. While the study may not be 95% sure that AML is linked to glyphosate, it may be 90% sure. And, with a deadly form of cancer like AML, pesticide applicators, farmers, and other highly exposed people may want to take protective measures, even if studies are only 90% confident in the link to AML cancer. I recommend that researchers present a range of relevant confidence levels, so that the public, regulators, and others can be fully informed.