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EPA Proposes Hormone Tests for Chemicals

May 02, 1996|MARLA CONE | TIMES ENVIRONMENTAL WRITER

As concern mounts that chemical pollutants are feminizing animals and perhaps depleting human sperm, the U.S. Environmental Protection Agency has proposed new guidelines requiring pesticide manufacturers to screen their products for the ability to alter hormones.

The EPA's move is the government's first step toward trying to protect the public from some of the risk posed by an array of chemicals, known as endocrine disrupters, that mimic estrogen or block testosterone.

Under the new guidelines, chemical manufacturers would look for abnormal estrogen cycles and sperm counts and malformed genitals of adult laboratory rats and their offspring after exposure to pesticides. Discovery of significant effects could lead to restrictions on new pest-killing products and perhaps some already used by farmers, home gardeners and others.

The guidelines--part of a broader package of changes to update the EPA's methods of screening pesticides for health effects--are expected to be approved by the agency's Science Advisory Board in September and could be implemented by the end of this year.

The proposal comes at the crest of a wave of worldwide concern among many scientists about the effects that gender-warping pollution may be having on fertility and reproductive organs.

Scientific studies have shown that many wild animals have half-male, half-female sex organs and abnormal estrogen and testosterone levels because of pesticides and industrial chemicals that act like hormones. Included are birds on California's Channel Islands and in the Great Lakes, alligators in Florida, otters in the Pacific Northwest's Columbia River and trout in British rivers.

In humans, some researchers suspect that the hormone-mimicking chemicals could be causing a sharp decline in male fertility and an increase in rates of testicular and breast cancer, endometriosis and other reproductive disorders.

Several studies of European men show that average sperm counts have dropped by nearly half in the past 50 years--the same era in which modern chemicals emerged. Two new studies in the United States, however, found no such decline over 20 years, puzzling experts and stirring up a controversy about whether male fertility is declining.

Despite such uncertainties, Assistant EPA Administrator Lynn Goldman called the risks posed by hormone-altering pollution "a very important environmental problem to the Clinton administration." The EPA is especially worried about the threat to infants, since the chemicals appear to have the ability to pass through the mother's womb to damage the reproductive organs and fertility of unborn children, she said.

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"We at the EPA cannot sit here and say, 'These tests have worked for us for 20 years and we're going to keep on using them.' We have to update them as knowledge improves," said Goldman, who oversees pesticide and toxics control.

The tests would be used to screen all new pesticide products before they are sold, but they would be required only on a limited basis for the hundreds of compounds already in use.

"These tests are two-generation toxicity tests. They take a long time, they are very expensive, and not every chemical is going to need to run through it," Goldman said.

Every year, commercial farmers and residential gardeners in the United States apply hundreds of millions of pounds of pesticides that have imitated estrogen or impaired testosterone in some laboratory tests. Included are atrazine, a herbicide used on corn; endosulfan, used to kill insects on many fruits and vegetables, and the farm and yard weedkiller 2,4-D.

Chemical manufacturers acknowledge that wild animals in some highly contaminated areas are in danger of altered hormones, but they say the threat to people, who are exposed to far less pesticide residue, is hypothetical. More research is needed, they say, before it is known whether there is any threat of problems with human sperm or reproduction.

Pesticide industry officials said they support the EPA proposal to update the guidelines, although they say their current tests have been effective in screening chemicals for serious reproductive problems.

"It's a natural evolution of upgrading our ability to refine these tests--do a little bit better, if you will," said John McCarthy, a vice president of the American Crop Protection Assn., which represents major pesticide companies, including Monsanto, DuPont and Rhone-Poulenc. "But I don't think it's going to find adverse effects we couldn't find before with the standard tests we've used all along."

Current pesticide screening tests had been designed to examine whether a chemical causes the more obvious forms of health damage--cancerous tumors, low birth rates and birth defects. But new research has shown that pollution is capable of causing biological damage in animals--such as defective sperm--that is more subtle and could be missed under the EPA's basic tests.

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