Glyphosate is the most widely used pesticide in the world.1 It is also, arguably, the most controversial. Since being classified as “probably carcinogenic to humans” by the International Agency for Research on Cancer (IARC) in 2015,2 glyphosate has received close scrutiny from scientists and regulatory bodies. A new study in this issue of Environmental Health Perspectives by Chang et al.3 provides important new evidence to support glyphosate hazard assessment.
The IARC conclusion was driven by the results of animal cancer bioassays and mechanistic studies—mostly produced in vitro or, in nonhumans, in vivo—indicating DNA and chromosomal damage and oxidative stress induced by glyphosate and glyphosate formulations.4 The evidence from human studies of cancer was considered “limited” by IARC given that it included positive associations between glyphosate and incidence of non-Hodgkin’s lymphoma from several retrospective case–control studies but no such association from the Agricultural Health Study, the only prospective cohort study published at the time of the agency’s review.4 Limitations of the body of evidence and differences in interpretation have influenced subsequent hazard assessments, such as those from the U.S. Environmental Protection Agency5 and the European Chemicals Agency.6
Read JPB Fellow Leah Schinasi full article here.