UNIONDALE, N.Y. -- In a Long Island laboratory where steel-clawed robots in glass cages shuffle tiny trays of cells all day and all night, the Environmental Protection Agency is gearing up for one of the most ambitious projects ever proposed to test chemicals found in everyday products for harmful side effects.
Under contract to the agency, OSI Pharmaceuticals Inc. has been asked to show how the drug industry's advanced automated techniques for hunting down useful compounds could also be used to quickly screen thousands of everyday chemicals, from plastics to pesticides, looking for those that might interfere with the hormonal systems of people and wildlife.
OSI's scientists have genetically engineered human cells with DNA from fireflies so that the cells glow when a chemical sample triggers the same molecular switches that in normal cells would respond to hormones. That glow is like a yellow warning light, a signal that the chemical ought to be rigorously tested using laboratory animals.
These experiments are crucial to a new plan, drafted over the past two years by an expert committee of several dozen scientists, industry representatives and environmentalists, to survey the entire chemical landscape looking for what molecular biologists call endocrine disrupters: substances that can mimic or interfere with the body's hormones and cause problems with reproduction, development and behavior.
The action is in response to a growing body of research indicating that man-made industrial chemicals and pesticides may commit a kind of molecular sabotage within the body's regulatory apparatus, possibly causing birth defects, low sperm counts, breast cancer, mental impairment and a range of other ailments.
How serious this problem is and what should be done about it are among the most hotly disputed of environmental issues, and the plan does not address what steps might eventually have to be taken to restrict the use of chemicals that are found to be harmful. This is a question with great economic and environmental implications.
Even though the scientific knowledge is still evolving, the advisory committee found, there is "appropriate widespread agreement" that a screening and testing program is needed.
"Increased screening is a first line of defense and a significant first step in limiting exposure to potentially dangerous substances," said Carol Browner, the EPA administrator, endorsing the committee's recommendations. Groups representing chemical and pesticide companies have also backed the plan.
Many kinds of commercial chemicals commonly found in industrial wastes, solvents, cleansers, pesticides, food additives, plastics, cosmetics, nutritional supplements, petroleum byproducts and throughout the environment would be scrutinized, at costs that some experts suggested could exceed $100 million.
"The committee has given us a very aggressive approach, which is to start with a focus on the 15,000 chemicals that are produced in amounts of 10,000 pounds or more per year," said Lynn Goldman, EPA's assistant administrator for pesticides and toxic substances, who headed the committee.
"I was very happy about where it went," said Goldman, who is a toxicologist and pediatrician. "They created a way for us to take a huge step forward. The amount of knowledge that is going to be generated to better protect the public and the environment is considerable."
Two years ago, Congress ordered the EPA to develop ways of screening pesticide residues in food and contaminants in drinking water to see whether any of them are dangerous endocrine disrupters. The agency put together the advisory committee, which has just completed a report that goes well beyond food and water quality to recommend what officials are calling the most sweeping program of toxicological screening and testing ever undertaken.
The project, if implemented as planned, would examine whether individual chemicals or their mixtures, including some naturally occurring compounds, affect either people or wildlife by acting on three primary endocrine systems, those governing estrogen, androgen and thyroid hormones. In the endocrine systems of nearly all animals, glands located throughout the body synthesize hormones and secrete them into the bloodstream. Receptors in the cells of various organs and tissues respond to these chemical messages to regulate sexual development, reproduction, metabolism, the brain and central nervous system, and other bodily functions.
The proposal is so ambitious that it would be impractical to subject every chemical to its full battery of tests. So the committee is recommending a system of triage to sort the estimated 87,000 chemicals that are in use.
Some of them, like polymers with molecules too large to cross cell membranes, are unlikely to pose endocrine problems and have been excluded. Of more than 62,000 chemicals that remain, the 15,000 produced in large quantities, plus all pesticides, would be the first to be screened.
Even the initial screening of 15,000 high-volume chemicals would be a daunting task if not for the new technologies that are being tried out in the Long Island laboratory.
OSI Pharmaceuticals, using much the same techniques, already screens 7 million chemicals a year looking for potential new medicines, and midway through the EPA committee's review, its experts realized that the same approach might well be used to set priorities for screening potential endocrine disrupters.
Under the agency's plan, a chemical would be subjected to comprehensive batteries of biological assays, including tests on laboratory mammals, birds, amphibians, fish and shrimp, after the initial screening suggests that it needed further testing.
Those animals would be dosed with chemicals and closely examined for effects that are thought to be caused by endocrine disruption, like changes in the size of uterine or brain tissues.
Though some of these tests have been used before, not all have been used to assess endocrine disruption, and there are also difficult questions about whether it is appropriate to use these tests to examine the effects of very small doses of chemicals.
The expert committee warned that only fully validated tests should be adopted, and there is some question how long that might delay the project. But most participants believe that in two to five years, the screening ought to be in full swing.
"These kinds of things don't come along very often, where you have both science evolving and a regulation evolving together," said Theodore Schettler, a doctor who practices at the East Boston Neighborhood Health Center in Massachusetts and represented Physicians for Social Responsibility, an advocacy group, on the EPA's advisory council. "That is probably the way it ought to be, rather than waiting till you have a smoking gun and a body count before doing anything."
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