Exposure to
chemical in Roundup increases risk for cancer
Jackson Holtz, UW News
Exposure to glyphosate — the world’s
most widely used, broad-spectrum herbicide and the primary ingredient in the
weedkiller Roundup — increases the risk of some cancers by more than 40
percent, according to new research from the University of Washington.
Various reviews and international
assessments have come to different conclusions about whether glyphosate leads
to cancer in humans.
The research team conducted an
updated meta-analysis — a comprehensive review of existing literature — and
focused on the most highly exposed groups in each study. They found that the
link between glyphosate and Non-Hodgkin Lymphoma is stronger than previously
reported.
Their findings were published this month in the online journal Mutation Research/Reviews in Mutation Research.
“Our analysis focused on providing
the best possible answer to the question of whether or not glyphosate is
carcinogenic,” said senior author Lianne
Sheppard, a professor in the UW departments
of Environmental & Occupational Health Sciences and Biostatistics.
“As a result of this research, I am even more convinced that it is.”
“As a result of this research, I am even more convinced that it is.”
By examining epidemiologic studies
published between 2001 and 2018, the team determined that exposure to
glyphosate may increase the risk of Non-Hodgkin Lymphoma by as much as 41
percent.
The authors focused their review on epidemiological research in humans but also considered the evidence from laboratory animals.
The authors focused their review on epidemiological research in humans but also considered the evidence from laboratory animals.
“This research provides the most
up-to-date analysis of glyphosate and its link with Non-Hodgkin Lymphoma,
incorporating a 2018 study of more than 54,000 people who work as licensed
pesticide applicators,” said co-author Rachel Shaffer, a UW doctoral student in
the Department of Environmental & Occupational Health Sciences.
“These findings are aligned with a
prior assessment from the International Agency for Research on Cancer, which
classified glyphosate as a ‘probable human carcinogen’ in 2015,” Shaffer said.
Glyphosate first was introduced as
an herbicide in 1974.
Usage in the agricultural industry has soared, particularly since the mid-2000s when the practice of “green burndown” was introduced, in which glyphosate-based herbicides are applied to crops shortly before harvest. As a consequence, crops now are likely to have higher residues of glyphosate.
Usage in the agricultural industry has soared, particularly since the mid-2000s when the practice of “green burndown” was introduced, in which glyphosate-based herbicides are applied to crops shortly before harvest. As a consequence, crops now are likely to have higher residues of glyphosate.
Researchers say more studies are
needed to account for the effects of increased exposures from green burndown,
which may not be fully captured in the existing studies reviewed in this new
publication.
Co-authors include Luoping Zhang and
Iemaan Rana in the Division of Environmental Health Sciences at the University
of California, Berkeley, and Emanuela Taioli in the Icahn School of Medicine at
Mount Sinai, New York.
Funding was provided by the National
Institutes of Environmental Health Sciences award T32ES015459 and the University of Washington Retirement
Association Aging Fellowship.