******************** POSTING RULES & NOTES ********************
#1 YOU MUST clip all extraneous text when replying to a message.
#2 This mail-list, like most, is publicly & permanently archived.
#3 Subscribe and post under an alias if #2 is a concern.
(With a president functioning as if he were in the movie "Idiocracy", it
comes as no surprise that his EPA director overrides his own scientists
to allow a pesticide to be used that causes children to have lower IQ
NY Times, May 16 2017
A Strong Case Against a Pesticide Does Not Faze E.P.A. Under Trump
By RONI CARYN RABIN
Some of the most compelling evidence linking a widely used pesticide to
developmental problems in children stems from what scientists call a
Though in this case, there was nothing natural about it.
Chlorpyrifos (pronounced klor-PYE-ruh-fahs) had been used to control
bugs in homes and fields for decades when researchers at Columbia
University began studying the effects of pollutants on pregnant mothers
from low-income neighborhoods. Two years into their study, the pesticide
was removed from store shelves and banned from home use, because animal
research had found it caused brain damage in baby rats.
Pesticide levels dropped in the cord blood of many newborns joining the
study. Scientists soon discovered that those with comparatively higher
levels weighed less at birth and at ages 2 and 3, and were more likely
to experience persistent developmental delays, including hyperactivity
and cognitive, motor and attention problems. By age 7, they had lower IQ
The Columbia study did not prove definitively that the pesticide had
caused the children’s developmental problems, but it did find a
dose-response effect: The higher a child’s exposure to the chemical, the
stronger the negative effects.
That study was one of many. Decades of research into the effects of
chlorpyrifos strongly suggests that exposure at even low levels may
threaten children. A few years ago, scientists at the Environmental
Protection Agency concluded that it should be banned altogether.
Yet chlorpyrifos is still widely used in agriculture and routinely
sprayed on crops like apples, oranges, strawberries and broccoli.
Whether it remains available may become an early test of the Trump
administration’s determination to pare back environmental regulations
frowned on by the industry and to retreat from food-safety laws,
possibly provoking another clash with the courts.
In March, the new chief of the E.P.A., Scott Pruitt, denied a
10-year-old petition brought by environmental groups seeking a complete
ban on chlorpyrifos. In a statement accompanying his decision, Mr.
Pruitt said there “continue to be considerable areas of uncertainty”
about the neurodevelopmental effects of early life exposure to the
Even though a court last year denied the agency’s request for more time
to review the scientific evidence, Mr. Pruitt said the agency would
postpone a final determination on the pesticide until 2022. The agency
was “returning to using sound science in decision-making — rather than
predetermined results,” he added.
Agency officials have declined repeated requests for information
detailing the scientific rationale for Mr. Pruitt’s decision.
Lawyers representing Dow and other pesticide manufacturers have also
been pressing federal agencies to ignore E.P.A. studies that have found
chlorpyrifos and other pesticides are harmful to endangered plants and
A statement issued by Dow Chemical, which manufactures the pesticide,
said: “No pest control product has been more thoroughly evaluated, with
more than 4,000 studies and reports examining chlorpyrifos in terms of
health, safety and environment.”
A Baffling Order
Mr. Pruitt’s decision has confounded environmentalists and research
scientists convinced that the pesticide is harmful.
Farm workers and their families are routinely exposed to chlorpyrifos,
which leaches into ground water and persists in residues on fruits and
vegetables, even after washing and peeling, they say.
Mr. Pruitt’s order contradicted the E.P.A.’s own exhaustive scientific
analyses, which had been reviewed by industry experts and modified in
response to their concerns.
In 2015, an agency report concluded that infants and children in some
parts of the country were being exposed to unsafe amounts of the
chemical in drinking water, and to a dangerous byproduct. Agency
researchers could not determine any level of exposure that was safe.
An updated human health risk assessment compiled by the E.P.A. in
November found that health problems were occurring at lower levels of
exposure than had previously been believed harmful.
Infants, children, young girls and women are exposed to dangerous levels
of chlorpyrifos through diet alone, the agency said. Children are
exposed to levels up to 140 times the safety limit.
“The science was very complicated, and it took the E.P.A. a long time to
figure out how to deal with what the Columbia study was saying,” said
Jim Jones, who ran the chemical safety unit at the agency for five
years, leaving after President Trump took office.
The evidence that the pesticide causes neurodevelopmental damage to
children “is not a slam dunk, the way it is for some of the most
well-understood chemicals,” Mr. Jones conceded. Still, he added, “very
few chemicals fall into that category.”
But the law governing the regulation of pesticides used on foods doesn’t
require conclusive evidence for regulators to prohibit potentially
dangerous chemicals. It errs on the side of caution.
The Food Quality Protection Act set a new safety standard for pesticides
and fungicides when it was passed in 1996, requiring the E.P.A. to
determine that a chemical can be used with “a reasonable certainty of no
The act also required the agency to take the unique vulnerabilities of
young children into account and to use a wide margin of safety when
setting tolerance levels.
Children may be exposed to multiple pesticides that have the same toxic
mechanism of action at the same time, the law noted. They’re also
exposed through routes other than food, like drinking water.
Environmental groups returned last month to the United States Court of
Appeals for the Ninth District, asking that the E.P.A. be ordered to ban
the pesticide. The court has already admonished the agency for what it
called “egregious” delays in responding to a petition filed by the
groups in 2007.
The E.P.A. responded on April 28, saying it had met its deadline when
Mr. Pruitt denied the petition.
Erik D. Olson, director of the health program at Natural Resources
Defense Council, one of the groups petitioning the E.P.A. to ban
“The E.P.A. has twice made a formal determination that this chemical is
not safe,” Mr. Olson said. “The agency cannot just decide not to act on
that. They have not put out a new finding of safety, which is what they
would have to do to allow it to continue to be used.”
Chlorpyrifos belongs to a class of pesticides called organophosphates, a
diverse group of compounds that includes nerve agents like sarin gas.
It acts by blocking an enzyme called cholinesterase, which causes a
toxic buildup of acetylcholine, an important neurotransmitter that
carries signals from nerve cells to their targets.
Acute poisoning with the pesticide can cause nausea, dizziness,
convulsions and even death in humans, as well as animals.
But the scientific question has been whether humans, and especially
small children, are affected by chronic low-level exposures that don’t
cause any obvious immediate effects — and if so, at what threshold these
exposures cause harm.
Scientists have been studying the impact of chlorpyrifos on brain
development in young rats under controlled laboratory conditions for
decades. These studies have shown that the chemical has devastating
effects on the brain.
“Even at exquisitely low doses, this compound would stop cells from
dividing and push them instead into programmed cell death,” said
Theodore Slotkin, a scientist at Duke University Medical Center, who has
published dozens of studies on rats exposed to chlorpyrifos shortly
In the animal studies, Dr. Slotkin was able to demonstrate a clear
cause-and effect relationship. It didn’t matter when the young rats were
exposed; their developing brains were vulnerable to its effects
throughout gestation and early childhood, and exposure led to structural
abnormalities, behavioral problems, impaired cognitive performance and
And there was no safe window for exposure. “There doesn’t appear to be
any period of brain development that is safe from its effects,” Dr.
Manufacturers say there is no proof low-level exposures to chlorpyrifos
causes similar effects in humans. Carol Burns, a consultant to Dow
Chemical, said the Columbia study pointed to an association between
exposure just before birth and poor outcomes, but did not prove a
Studies of children exposed to other organophosphate pesticides,
however, have also found lower IQ scores and attention problems after
prenatal exposure, as well as abnormal reflexes in infants and poor lung
function in early childhood.
“When you weigh the evidence across the different studies that have
looked at this, it really does pretty strongly point the finger that
organophosphate pesticides as a class are of significant concern to
child neurodevelopment,” said Stephanie M. Engel, an associate professor
of epidemiology at University of North Carolina at Chapel Hill.
Dr. Engel has published research showing that exposure to
organophosphates during pregnancy may impair cognitive development in
But Dr. Burns argues that other factors may be responsible for cognitive
impairment, and that it is impossible to control for the myriad factors
in children’s lives that affect health outcomes. “It’s not a criticism
of a study — that’s the reality of observational studies in human
beings,” she said. “Poverty, inadequate housing, poor social support,
maternal depression, not reading to your children — all these kinds of
things also ultimately impact the development of the child, and are
While animal studies can determine causality, it’s difficult to do so in
human studies, said Brenda Eskenazi, director of the Center for
Environmental Research and Children’s Health at the University of
“The human literature will never be as strong as the animal literature,
because of the problems inherent in doing research on humans,” she said.
With regard to organophosphates, she added, “the animal literature is
very strong, and the human literature is consistent, but not as strong.”
If the E.P.A. will not end use of the pesticide, consumer preferences may.
In California, the nation’s breadbasket, use of chlorpyrifos has been
declining, Dr. Eskenazi said. Farmers have responded to rising demand
for organic produce and to concerns about organophosphate pesticides.
She is already concerned about what chemicals will replace it. While
organophosphates and chlorpyrifos in particular have been scrutinized,
newer pesticides have not been studied so closely, she said.
“We know more about chlorpyrifos than any other organophosphate; that
doesn’t mean it’s the most toxic;” she said, adding, “There may be
others that are worse offenders.”
Full posting guidelines at: http://www.marxmail.org/sub.htm
Set your options at: