permaculture

["Emily A. Noble" <guinep@theriver.com>]

Title: FW: EPA Increases Risk Estimate of Dursban

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From: Arizona Toxics Information <aztoxic@primenet.com>
To: guinep@theriver.com,CONS-EQST-PESTICIDE-FORUM@LISTS.SIERRACLUB.ORG
Subject: Fwd: EPA Increases Risk Estimate of Dursban
Date: Thu, Jun 1, 2000, 10:04 AM


Date: Thu, 01 Jun 2000 10:38:10 -0700
From: Waste Forum
Subject: EPA Increases Risk Estimate of Dursban
EPA Increases Risk Estimate of Pesticide Dursban
By David Brown and Joby Warrick
Washington Post Staff Writers
Thursday, June 1, 2000; Page A01
The Environmental Protection Agency has concluded that one of the most
commonly used pesticides, a compound sold as Dursban and found in
dozens of home-and-garden products, may be more dangerous to people
than previously thought, according to sources familiar with the
decision.
The EPA's conclusion, which is expected to be announced June 8, will
effectively remove the pesticide, also known as chlorpyrifos, from all
over-the-counter products. Although farmers will still be allowed to
spray it on crops, the chemical's agricultural use will be reduced to
a degree not yet decided. Whether professional exterminators will be
allowed to employ it to kill termites, ants and cockroaches is
uncertain.
The move culminates the most extensive scientific assessment of a
pesticide in EPA history, and one of the more contentious. Last
October, the agency proposed making the acceptable exposure level of
chlorpyrifos one-third of what it is currently. Now the level will be
even more stringent: one-tenth of what's currently allowed.
The decision is part of a systematic review of the safety of
pesticides EPA is required to make under the 1996 Food Quality
Protection Act. The law is designed to protect children in particular
from the toxic effects of pesticides. The newly estimated hazards of
chlorpyrifos are based on experiments showing the substance can cause
brain damage in fetal rats, not on human studies.
The pesticide is a member of the organophosphate family of compounds,
whose most potent cousins include nerve gases used as chemical
weapons. Its only American manufacturer is Dow Chemical Co. About 800
consumer products contain the compound. They include Ortho Lawn Insect
Spray, Real Kill Wasp & Hornet Killer II, and Spectracide Dursban
Indoor & Outdoor Insect Control. The EPA has determined that the
compound poses no imminent threat to public health, and consequently
won't order a recall of products containing it.
About 11 million pounds of chlorpyrifos are used each year by farmers
and fruit growers; about 5 million pounds by industrial, commercial
and government buyers; and about 3 million pounds by the
home-and-garden market. Sales in the mid-1990s were about $500 million
per year, according to the National Center for Food and Agricultural
Policy, a research firm in Washington.
Public concern about pesticide exposure - and the expectation of
further government regulation - has driven many users of the compound
in the last few years to find alternatives. For example, some dog and
cat flea collars now contain insecticides called pyrethroids instead
of chlorpyrifos. Many exterminators use chemical baits rather than
pesticides to rid houses of termites.
"Dursban is still an important product, but not the most important
product in every category," said Mancer Cyr, a consultant with Kline &
Co., a Little Falls, N.J., company that gathers market data for the
chemical industry. In the home-and-garden market, about half the
chlorpyrifos used is bought by consumers and half is applied by
exterminators and lawn care companies, he said.
Several environmental and public health interest groups have
campaigned hard against the compound, calling it one of the most
hazardous pesticides in general use. Last month, 12 scientists
(including a former EPA executive and a former consultant to the
agency) urged EPA Administrator Carol M. Browner, in a letter, to
"tightly restrict" agricultural use of the compound, and "ban
outright" its use in homes and schools.
"We anticipate that the outcome of the EPA's reevaluation of
chlorpyrifos will be manageable from a business standpoint for Dow
AgroSciences," said Garry Hamlin, spokesman for the Dow subsidiary
that makes the compound. "Having said that, during the public comment
period [last autumn], about 4,000 people wrote into the public docket
saying why chlorpyrifos was essential to their businesses."
Crucial in the EPA's decision was a study by Dow - one of more than
100 the company was required to perform - that showed brain damage in
fetal rats whose mothers were given the compound.
Normally, EPA sets a safe exposure level for a pesticide such as
chlorpyrifos at one one-hundredth of the maximal concentration at
which there are no detectable effects on an adult animal. Under the
1996 law, however, that hundred-fold safety margin is increased
ten-fold more if there is any evidence that infants or children are
especially vulnerable to a pesticide. The detection of
"neurodevelopmental effects" in the rats triggered that part of the
regulation.
The level of chlorpyrifos that will now be deemed safe for children
will be one one-thousandth of the "no-effect level." Such a stringent
level effectively rules out home use of chlorpyrifos because consumers
couldn't use the chemical without bumping up against that very low
ceiling.
For example, the Environmental Working Group, a Washington research
and lobbying organization, estimates that a person using a
chlorpyrifos "crack-and-crevice" spray would be exposed to about four
times the concentration of the compound as would be permissible under
the new guidelines.
"It would be imprudent to assume that these findings in animals do not
apply to people," said Philip J. Landrigan, a pediatrician and
director of the Center for Children's Health and the Environment at
New York's Mount Sinai School of Medicine, who was one of the authors
of the letter to Browner.
Also troubling to some scientists is chlorpyrifos's staying power and
its ability to move from one surface to another. One study showed that
when it is sprayed in the home, some becomes volatile and settles on
rugs, furniture and toys, from which it is later released, said David
Wallinga, a physician and scientist with the Natural Resources Defense
Council, a Washington environmental group.
"Even when used as directed it can end up in places in schools and
homes where children can be exposed," Wallinga said. "You just can't
anticipate what the effects will be."
Defenders of the chemical, however, point to unintended effects that
might arise from a ban. They include a possible rise in asthma, which
is especially prevalent in low-income city-dwellers and often
triggered by cockroach body fragments and feces. Another is the
decreased availability of inexpensive fresh vegetables, which could
have subtle ramifications for public health.
The chlorpyrifos decision was made less than a year after the EPA
moved to restrict uses of two other popular organophosphate
pesticides, methyl parathion and azinphos methyl. A fourth widely used
pesticide, diazinon, also appears to be in trouble, based on agency
scientific documents that suggest risks to homeowners and workers who
apply the chemical. Diazinon is also widely used as a home-and-garden
insecticide.
"What we're seeing is a growing official indictment of this whole
class of older, dangerous pesticides," said Richard Wiles of the
Environmental Working Group, which supports a ban on all
organophosphate pesticides. "They're very dangerous to children, and
no amount of lobbying by pesticide companies can change that fact."
EPA is negotiating with Dow Chemical over what uses of chlorpyrifos
will be permitted. If the manufacturer (and its customers) don't
voluntarily agree to restrict its use to reach the new exposure level,
the agency can force the restriction.
c 2000 The Washington Post Company