|
|
The advantages are time and cost, Shelby says. Conventional toxicological tests can take a year or two and cost a mil or two. When he and his colleagues used the screen on 10 known or suspected estrogen disrupters, the results were "consistent with what is known about the estrogenic properties" of the chemicals (see "Endocrine Disrupter Screens..." in the bibliography).
A full-employment act for toxicologists?
But estrogen is just part of the issue, since the EPA wants to evaluate chemicals that mimic or block estrogens, androgens and thyroid hormones. And it's not yet  clear if only new chemicals, or, conceivably, all chemicals on the market would be subject to screening. In any case, the NIEHS work does suggest a direction to pursue in the awesome screening process.
Yet cell-culture tests can be misleading, says Judith Weis, a Rutgers University biology professor. "You have to look at whole animals. The quick and dirty in-vitro ('in glass') tests may give you supplemental information," but they are not conclusive.
In designing the screening process, Weis, a member of EDSTAC, the EPA's advisory committee, suggests including fish, amphibians and birds, where endocrine disruption has been demonstrated. "There's no guarantee [this will be enough, but] you can't include everything," she says.
It's important to remember that while wildlife effects of endocrine disrupters are pretty well demonstrated, the effects of environmental endocrine disrupters on people are more speculative. "Nobody has shown clearly and convincingly a cause and effect of a specific agent on human health," says Thomas Crisp, an EPA scientist who helped write an assessment of endocrine disrupter science for the agency.
You haven't answered the question.
Can this process really work?
|
