EPA Ready to Sharply Curb Use of Common Pesticide
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.
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.
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) urged EPA Administrator Carol 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.
The level of chlorpyrifos that now will be deemed safe for children will effectively rule out home use of chlorpyrifos. 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.
Troubling to some scientists is chlorpyrifos’ staying power and its ability to move from one surface to another. One study showed that when it is sprayed in the home, some 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.
Defenders of the chemical, however, point to unintended effects that might arise from a ban. They include a possible rise in asthma, which is 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.
“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.
