The Cruelest Testing Program Yet
Following on the heels of the ill-conceived and cruel High Production Volume Challenge program and the Voluntary Children's Chemical Evaluation Program, the Environmental Protection Agency (EPA) is now pushing the largest animal testing program in history, calling for tests on up to 87,000 chemicals, using as many as 1.2 million animals for every 1,000 chemicals tested. Like its predecessors, this program will do nothing to protect human health.
The 1996 Food Quality Protection Act gave the EPA the power to initiate the Endocrine Disrupter Screening Program. Concern over endocrine disrupters—chemicals that affect the normal action of hormones in the body—was largely prompted by a 1996 book, Our Stolen Future by Theo Colborn. The book noted reproductive and developmental abnormalities in wildlife and suggested that chemicals which interfered with normal hormonal systems caused these effects, and that these same chemicals might be affecting hormonal regulation in humans as well.
The endocrine system produces hormones that convey signals from one part of the body to another, activating certain functions when needed or turning these functions off when appropriate. Hormones work by fitting into receptors. When the proper hormone fits itself into the proper receptor—like a key fitting into a lock—the body knows that it is supposed to undertake whatever action is dictated by that particular hormone-receptor system.
Chemicals can interfere with this process. A hormone-like chemical might just about fit into the receptor. If it is close enough, the body may react as if the real hormone had triggered it, as if someone had used a skeleton key to open a lock that shouldn't be opened. Or a chemical might fit into a receptor, but not trigger anything—it blocks hormone action, like glue in a lock. Either way, chemicals can disrupt the normal endocrine function in the body.
The EPA persists in acting as if mice and rats are tiny little people, assuming that what is safe for rodents will be safe for humans. As noted in the Autumn 1999 Good Medicine, different species process chemicals along different metabolic routes and at different rates. One species might turn a chemical into a deadly poison, while another easily breaks it down and excretes it with no problem. For example, saccharin produces carcinogens in a rat's body, but not in a human's.
What the Future Holds
The best way to identify potential endocrine disrupting chemicals is to use in vitro technology that directly determines whether or not a chemical is able to bind with human hormone receptors at all. If it does, it's a good bet that the chemical might be an endocrine disrupter. If not, it is unlikely to affect human hormonal function. One such screening method is high-throughput screening (HTPS) representing the cutting edge of modern molecular biology and science. Unfortunately, the EPA has ignored the tests in favor of archaic rat and mouse tests.