To get high-risk pesticides out of our bodies, insulate the EPA from politics and follow the science
Dr. Philip J. Landrigan and Charles Benbrook for the Environmental Health News
But this is not a new phenomenon. In the 1970s and 1980s researchers clearly established that feeding pigs and chickens low-levels of antibiotics to promote faster growth was creating new antibiotic-resistant bacteria.
Despite
significant investment of public research dollars over decades to highlight
this problem, large-scale animal feeding operations did little to curtail
antibiotic use. Today feedlots remain a primary source of newly resistant
bacteria complicating treatment of human infections.
Science
heals only when heeded. Many of the problems plaguing our food and agricultural
system persist because politicians, regulators and business leaders routinely
ignore, twist, and undermine science. Willful disregard of science is often
good for business. Few examples show this as clearly as the Environmental
Protection Agency's checkered history in protecting the public from adverse
health and environmental impacts triggered by EPA-approved uses of pesticides.
Chlorpyrifos exposure warnings
Take
for example the efforts by the EPA to curtail risks arising from exposures to
chlorpyrifos.
But
first, some background is helpful explaining the unique role this insecticide
has played in stress-testing the EPA's pesticide regulatory process over the
last 30 years.
In
1987 we helped start a National Academy of Sciences project that led to the release
six years later, in 1993, of a seminal report, Pesticides in the Diets
of Infants and Children. Charles Benbrook was the staff director of the
unit of the NAS carrying out this EPA-funded study; Phil Landrigan was the
chair of the NAS study committee.
The
1993 report and its recommendations were widely embraced by the industry,
environmentalists and the scientific community. Three years later, in a rare,
unanimous vote in both the House and Senate, Congress passed the Food Quality
Protection Act (FQPA). This historic legislation moved most of the
recommendations in the 1993 NAS report into federal law. It gave EPA the
mandate and new tools needed—or so we hoped—to finally deal with pesticides
capable of damaging children's brains and disrupting a child's normal
development.
High-risk
pesticides, altered brain development
In the NAS report, chlorpyrifos was the "poster child" of high-risk pesticides known to increase the risk of neurodevelopment harm. As the debate over our recommendations matured in Congress, the impact of the FQPA on chlorpyrifos was front and center. From FQPA passage in 1996 through the four-year process of developing the detailed science policies and risk assessment procedures needed to implement the new law's mandates, potential impacts on chlorpyrifos was always a focus and flash point.
In
2000 EPA announced a deal with Dow AgroSciences, the major manufacturer—and
defender—of chlorpyrifos. Dow agreed to not contest EPA cancellation of nearly
all home and residential uses, and the EPA agreed to preserve most of the
agricultural uses of chlorpyrifos. As a result, the deal ended sometimes high
exposures impacting relatively few pregnant women and children living in
treated homes and apartments, but allowed widespread farm use to continue,
along with routine, daily exposures to essentially all consumers via food and
drinking water.
Controversy
in the wake of this outcome intensified scientific focus on chlorpyrifos. In
the next two decades hundreds more animal studies would confirm the link
between low-level, prenatal exposures to chlorpyrifos and altered brain
development in young animals. Dozens of papers traced the mechanisms of such
disruption to their biochemical, neurophysiological and genetic roots in many
different organisms, including people.
At
risk: Children's brains, behavior
Controversy
in the wake of this outcome intensified scientific focus on chlorpyrifos. In
the next two decades hundreds more animal studies would confirm the link
between low-level, prenatal exposures to chlorpyrifos and altered brain
development in young animals. Dozens of papers traced the mechanisms of such
disruption to their biochemical, neurophysiological and genetic roots in many
different organisms, including people.
But
the new science that most dramatically altered the EPA's assessment of
chlorpyrifos neurodevelopmental risk came from three epidemiologic studies
published by teams from the University of California-Berkeley, Columbia
University and the Mount Sinai School of Medicine. Especially taken together—as
EPA does in forming "weight of the evidence" science judgements—these
studies provided compelling, consistent evidence that chlorpyrifos exposures
during pregnancy disrupt brain and nervous system development.
The
impacts can include lasting impairment of children's cognitive abilities, IQ
and behavior. Such exposures can also lead to attention deficit/hyperactivity
disorder and autism, and other developmental and chronic health problems. And
paradoxically, scientists came to realize some adverse impacts can be brought
about at low doses, but not at higher ones, an unexpected but surprisingly
common feature of many chemicals known as endocrine disruptors.
New
science was also prominently featured in litigation pursued by a coalition of
environmental, farmworker and health organizations. It began in 2007, and its
14-year journey through the courts has culminated in a series of Ninth Circuit
U.S. Court of Appeals rulings in favor of the coalition.
'Your science doesn't matter'
The
most recent Ninth Circuit order gives the EPA two options. The agency must
determine, and explain, the science justifying its decision—that current and
retained chlorpyrifos tolerances are safe—as required by the FQPA. Or, the EPA
must move ahead with the process required to revoke all tolerances supporting
unsafe residues of chlorpyrifos in food and drinking water.
The
first option boils down to the Biden EPA endorsing the Trump EPA rejection of
the detailed chlorpyrifos human-health risk assessment completed by the agency
in 2015. That EPA chlorpyrifos assessment is the culmination of arguably the
most sophisticated risk assessment ever conducted on a pesticide anywhere in
the world. It concluded that prenatal chlorpyrifos exposures were likely
disrupting children's neurodevelopment at extraordinarily low levels of
exposure -- more than 1,000-fold lower than the levels of chlorpyrifos exposure
that the EPA previously thought were safe.
Upholding
the Trump Administration's rejection of that health assessment will be a slap
in the face of the dozens of EPA staff scientists who had contended with and
responded to a near-endless flurry of Dow challenges, regurgitation of flawed
industry studies and other well-financed diversionary tactics. This choice by
EPA would also send a regrettable message to the hundreds of independent
scientists and research institutions that stepped up and helped the EPA address
the chlorpyrifos-science challenges standing in the way of completing the 2015
chlorpyrifos risk assessment.
A
default to the Trump EPA position ignores nearly two decades of new science and
sends a chilling message to the research community: "Your science doesn't
matter."
Pesticide
regulation: Systemic reform
The capacity of chlorpyrifos to dodge the consequences of new science is not an isolated incident in the world of pesticide regulation. This is why we joined seven other scientists in publishing a commentary exposing systemic problems with pesticide use, risk assessment, and regulation in the journal Environmental Health.
Better
decisions depend on severing the roots of these problems.
The
same patterns evident in the history of chlorpyrifos regulation are evident in
the case of other pesticides. Routine registrant tactics include manipulation
of study designs, questionable statistical analyses, and bogus explanations of
why adverse impacts observed in animal studies are "not treatment
related."
Four
solutions for EPA reform
This
is why our first recommendation in the commentary may be the most important—we
call for a shift away from registrant-commissioned and -controlled studies to
mostly independent science in fulfilling core EPA study requirements. Such
EPA-funded studies can and should be paid for by the registration fees imposed
by EPA when asked to register a new pesticide use, or reregister existing uses.
Second,
we must redirect existing resources to more accurate and timely measurements of
pesticide levels in people. Today, the EPA depends almost solely on expensive,
indirect methods like testing for pesticides in food, water and air. Such
levels are just one of several parameters driving pesticide exposures. Our
recommended shift to heavier reliance on direct measures of pesticides in
people is especially crucial when, like today, overall pesticide reliance is
rising and big changes are occurring quickly in the mix of pesticides people
are exposed to.
Third,
pesticide regulators should place greater weight on new scientific tools that
are rapidly uncovering the mechanisms through which pesticides can cause
adverse human health and environmental outcomes. The deep-set EPA bias against
reliance on new science must end.
Fourth, we see a pressing need for pesticide risk-assessment science to integrate scientific information and tools from multiple disciplines. Science is moving fast, but regulatory test requirements and EPA risk assessment methods are stuck with test protocols and data requirements that were not even cutting-edge in the 1980s.
Pesticides
and inert ingredients
Our
commentary focuses on one other consequential problem with pesticide
regulation: In a rewrite of federal pesticide law in 1972, Congress classified
the chemical details of pesticide formulas as "Confidential Business
Information" not subject to public disclosure. In the 50 years since,
farmers, doctors treating people exposed to pesticides and scientists not
working for the EPA or a pesticide registrant have tried to understand and
prevent harm, and treat poisoning victims, without knowing the chemicals to
which people are exposed. This is like searching for a needle in a haystack
with leather gloves on.
The
"other ingredients" listed on pesticide labels are mixed into the
products sold to farmers and other pest managers to enhance pesticide
performance. These co-formulants promote ease of use and stability in various
mixtures with other pesticides and fertilizers. But some "other
ingredients" are toxic, and some are even more toxic than the active
ingredients in formulated products. Yet the EPA conducts very little testing on
these other ingredients, and almost none on the environmental fate, metabolism
and toxicity of the formulated products as sold and applied.
This
is why our commentary calls for a simple fix -- Congress needs to amend federal
law to direct the EPA to accurately and fully disclose on pesticide labels and
in chemical safety data sheets all the chemicals and their concentrations in
the pesticides people apply and to which the public is exposed.
Pesticide
use and exposures are already high, and are rising worldwide. Regulators need
better data, new tools and more accurate risk assessments based on real-world
conditions to reliably identify and avoid high-risk pesticide uses.
The
pragmatic steps and policy changes in our commentary are necessary in building
the capacity of the scientific community and regulators to mitigate high-risk
pesticide uses harming people. The need is most pressing, as stated nearly
30-years ago in the 1993 NAS report, in preventing harm to pregnant women,
infants and children, as well as those most heavily exposed because they apply
pesticides or live near farm fields or other places that are heavily sprayed.
Dr.
Phil Landrigan is the founding director of Boston College's Program in Global
Public Health and the Common Good, and serves as the chair of the Heartland
Health Research Alliance's Science Advisory Board.
Dr.
Charles Benbrook is the executive director of the Heartland Health Research
Alliance. He has served as an expert witness in pesticide litigation, including
an ongoing case involving chlorpyrifos.
