The Pursuit of Safety
Following the terrorist attacks of Sept. 11, we Americans abruptly turned our attention to the pursuit of safety. Yet threats, recognized or not, have always been with us. In this issue "Mixed Messages" reports on a subtle but real and present danger in our environment--endocrine disruptors. These chemicals--present in products from dish detergent to plastic water bottles--threaten the well-being and perhaps the survival of humans and wildlife. Minute amounts can interfere with hormonal messengers, potentially disrupting the body's internal communications. Some of these everyday chemicals can lower disease resistance. Some sabotage the development of intelligence and alter behavior. Some shuffle sexual development. Some impair fertility.
Evidence of abnormal reproductive organs has turned up around the world, from alligators in Florida to seals in Europe. Scientists such as Rachel Carson, author of Silent Spring, have warned of hazardous chemicals in our environment for decades. Why, then, have we been slow to recognize the risks?
For the most part, our society has deemed chemicals safe until proven harmful. Some 82,000 industrial chemicals are currently in use, according to Theo Colborn, World Wildlife Fund senior scientist and co-author of Our Stolen Future. Colborn herself made the mistake of assuming the harmlessness of useful compounds. When she was working as a pharmacist and raising a family, she and her husband cheerfully hung DDT-laden pest strips all over their house. Today she regrets exposing her children to the now-banned pesticide.
Proof of harm has been hard to establish, in part because endocrine disruptors don't follow a basic assumption of risk assessment?namely, that the effects of toxic substances typically increase as the dose increases. To assess toxicity, current tests examine relatively high levels of contamination. However, some endocrine-disrupting chemicals show harmful effects at low levels. "Mixed Messages" explains other complications of health testing.
These practically imperceptible toxins pose the greatest threat to the unborn, Colborn says. Humans develop in the womb under the influence of infinitesimal levels of natural hormones. It stands to reason that inconspicuous concentrations of hormone-mimicking chemicals could disrupt this delicate development. What's more, she says, even the most remote places cannot escape contamination carried by wind and water currents. In the high Arctic, researchers discovered unusually high levels of PCBs and other contaminants in human breast milk and babies.
How might we reduce the risks of such insidious chemicals? The web site ourstolenfuture.org makes some personal safety suggestions. For instance, people are warned not to microwave foods in plastic that might leach endocrine-disrupting compounds into the food. Likewise, consumers might choose to avoid using nail polish, eye glitter, hair spray, and other cosmetics that contain phthalates, which have caused reproductive birth defects in laboratory animals.
The web site also offers recommendations for policy makers: Commit federal funds to research, improve protective regulations, provide access to crucial information, build the capacity of the Centers for Disease Control and Prevention to monitor contamination levels and health impacts, and apply the precautionary principle. This last recommendation calls for shifting the burden of proof from demonstrating harmful impacts to proving safety. "If plausible doubt can be justified about the safety of chemical compounds," the web site says, "their use should be allowed only if the manufacturer can prove they represent no inappropriate threat to human or ecosystem health."
We ignore the risks of endocrine disruptors at our peril. Acquiring knowledge and acting on it, we have reason for hope. After all, our future may depend on how diligently we pursue safety today.
Kathleen Weflen, editor