Controversy and questions surround California’s listing of
weed killer as cancer cause
By
Carey Gillam for Environmental
Health News
California’s official listing of the world’s most widely used weed killer as a known carcinogen marks a milestone in what has been years of debate over the safety of the pesticide called glyphosate.
But
it by no means marks the end of controversy over the chemical, or arguments
over what warnings – if any – should be placed on an herbicide that is a mainstay
for U.S. farming and for maintaining household lawns and gardens, city parks
and school grounds.
Officials
with California’s Office of Environmental Health Hazard Assessment (OEHHA) have
until early April to work out guidelines for glyphosate product warnings before
requirements for such warnings take effect in July 2018.
At
the same time, OEHHA continues to face a court challenge from Monsanto Co.,
which introduced glyphosate more than 40 years ago, and makes billions of
dollars off glyphosate-based Roundup herbicides.
The
chemical, now off patent, is also active in hundreds of other herbicide
products.
“This is not the final step in the process... We will continue to aggressively challenge this improper decision,” Monsanto said in a statement.
California’s move to list glyphosate as a known
carcinogen was triggered by the March 2015 decision by the International Agency
for Research on Cancer (IARC) to classify glyphosate as a probable human carcinogen.
Under
a state law known as Proposition 65, California is required to add a chemical
to a list of known cancer-causing substances if it garners such a classification
by IARC.
The
law then requires businesses to notify Californians about significant amounts
of listed chemicals in products or released into the environment.
A
particularly contentious part of the ongoing battle now surrounds what level of
exposure California might allow without any warnings.
The
state has proposed what some
see as an overly generous “safe harbor” or “No Significant Risk Level” (NSRL)
for glyphosate at 1100 micrograms a day, meaning exposure levels and discharges
into drinking water sources below that benchmark would be exempt from warning
requirements.
That
level is significantly higher than amounts that have been shown to have
cancer-causing effects in several animal studies, however.
Critics
point to studies that have shown tumor developments in animals at doses of
glyphosate lower than 850 mg/kg/day and even lower than 250 mg/kg/day.
“That
NSRL would not be sufficiently health protective… We strongly urge OEHHA to
uphold its statutory purpose to protect humans from the harmful impacts of
glyphosate and lower the NSRL…” a group of scientists and environmental and
food safety advocates told OEHHA in a letter.
Nathan
Donley, Senior Scientist with the Center for Biological Diversity, said the
research OEHHA relied on showed an “uncharacteristic” dose response to
glyphosate, and if OEHHA would take other studies into account it would result
in a dramatic lowering of the NSRL.
“The
implications are enormous and it’s incredibly important that they get this
right,” he said.
Adding
intrigue to the debate, lawyers for scores of cancer victims currently suing Monsanto
over Roundup have turned up documents showing that before California regulators
set the NSRL they met privately with Monsanto.
Documents
obtained from OEHHA include notes from one
October 7, 2015 meeting between OEHHA staff and Monsanto officials and indicate
the parties discussed the company’s ideas about an
calculating an NSRL and what studies should be looked at for development of
that NSRL.
Among
the attendees listed on an OEHHA memo were the
agency’s Chief Deputy Director Allan Hirsch, Deputy Director for Scientific
Affairs Melanie Marty, and Chief Counsel Carol Monahan-Cummings.
The
handwritten notes indicate that there was some discussion of what has long been
a Monsanto talking point on glyphosate – that if glyphosate isn’t used, other,
more-toxic herbicides might be used instead.
California
attorney Pedram Esfandiary, whose firm is representing multiple cancer victims
suing Monsanto, also believes California regulators have not incorporated
adequate study data into their calculation of the NSRL.
He
said evidence developed through the litigation pending in federal court against
Monsanto shows the company has withheld important information regarding
glyphosate carcinogenicity.
Some documents obtained through the
litigation have
already prompted an investigation by the
inspector general for the U.S. Environmental Protection Agency into whether or
not an EPA official engaged in collusion with Monsanto regarding the safety
assessment of glyphosate.
And
there are many more relevant documents the lawyers are working to unseal now.
“Additional
documents pertinent to the Safe Harbor NSRL and Roundup/glyphosate
carcinogenicity are presently still under seal and it is strongly recommended
that OEHHA obtain access to such documents before OEHHA takes the potentially
precarious step of issuing an NSRL of 1100 micrograms,” Esfandiary and three
other attorneys involved in the case said in a letter to OEHHA. “The known
dangers of glyphosate warrant extensive investigation before Californians are
exposed to any amount…”
OEHHA
spokesman Sam Delson defended the agency’s proposed NSRL but said it is
possible that OEHHA could change the NSRL for glyphosate as the agency reviews
the input it has received from outside parties. NSRLs are developed to
determine the level of exposure from an individual source that would cause a
1-in-100,000 lifetime cancer risk.
“We
developed the proposed NSRL based on the best scientific information available
to us. Neither Monsanto nor any other group or individual influenced the
proposed NSRL beyond submitting comments or information for our consideration.”
He
noted that Monsanto opposes the proposed NSRL. Indeed, at a recent public
hearing Monsanto representatives said the only acceptable NSRL for glyphosate
would be “infinity.”
Several
of the state’s Prop. 65 listings have drawn controversy and litigation but none
have created the uproar that glyphosate has, according to Delson.
“The
decision to list glyphosate as a cancer cause has drawn by far the largest
number of written comments ever received,” he said. More than 10,600 comments
were submitted to OEHHA regarding the glyphosate listing and the NSRL issue.
The
deadline for adoption of the NSRL is early April, Delson said. The goal is to
have the NSRL finalized before the warning requirement takes effect in July
2018 so that companies will be able to determine whether they need to provide
warnings and/or reformulate products in ways that allow them to avoid the need
for warnings.
Food
products containing glyphosate residues that cause an exposure exceeding the
final NSRL would be included in the warning requirement, Delson said.
As
recently as June 20, Monsanto was continuing to press OEHHA to drop or
delay the glyphosate listing, arguing that the IARC classification was
invalid. OEHHA denied the request, clearing the
way for the July 7 listing.
The
company also continues to press the issue in the courts; it’s lawsuit against
OEHHA was dismissed by a Fresno County Superior Court judge in March but
Monsanto appealed the dismissal and that appeal is still pending. The company’s
effort to block the listing while the appeal is pending failed.
Carey
Gillam is the Research Director at U.S. Right to Know and a veteran journalist
who specializes in coverage of food, agriculture and environmental issues.
For
questions or feedback about this piece, contact Brian Bienkowski at bbienkowski@ehn.org.