veryone knows that World War II left us, as a legacy, the atomic bomb. Far fewer people are aware that the war also left us a chemical bomb, silently, inexorably ticking away, that may threaten our health, our intelligence, and even our ability to reproduce. It may be exploding as you read.
Before the war, only a few synthetic chemicals -- laboratory-made compounds that do not exist in nature -- had been invented. With the onset of the war, chemists eager to help their countries achieve victory began inventing plastics, pesticides, solvents, degreasers, insulators, and other materials that could be used to make more effective weapons, increase crop yields, and feed more soldiers. They were, understandably, more focused on success than on safety.
In peacetime, these same labs helped fuel the economic boom of the second half of the twentieth century, formulating new chemicals manufacturers needed to create cheaper, smarter products.
Federal regulation was fragmentary at best, and manufacturers were allowed to provide their own proofs of safety, a situation that remains true today. There are now more than 100,000 synthetic chemicals on the market, and these chemicals are everywhere. They enter our bodies and those of other animals through every possible route of transmission. They are in our food supply, so we eat them. They drift in the air, so we breathe them. (Carried on thermal currents, they have long since reached the Arctic, so polar bears breathe them too.) Present in landfills, they leach into the water supply, so we drink them. Released as effluent into lakes and rivers by factories, they affect the habitat of fish, frogs, and all aquatic life, right down to plankton. Ubiquitous in cosmetics, they are absorbed through our skin. Pregnant women pass them to their fetuses; mothers feed them to their newborns when they breastfeed. A large, uncontrolled scientific experiment has been in progress for the last 60 years, and the question now is: Can we figure out what the results are? And if those results show we are in danger, what we can do about it at this late date?
For almost two decades after the war, our great faith in the new chemistry went untested. It seemed as if one miracle after another emerged from the labs, providing abundant, cheap food, drugs to cure disease, and technology that made life easier and more pleasurable: televisions, dependable cars, inexpensive, reliable refrigerators to replace the icebox.
Rachel Carson pushed Americans to question these miracles when she published Silent Spring in 1962, and legislation was passed to address concerns she and others raised about environmental toxins. By the early 1970s, more warning signs had showed up on the radar. DDT, the pesticide that had saved American soldiers who fought in the South Pacific from malaria and been sprayed on millions of acres of cropland, was fingered as a killer of birds, especially the beloved bald eagle. Eggshells thinned by exposure to the compound meant fewer hatchlings survived. DES, a drug believed to prevent miscarriage, was found to cause cancer in the young women whose mothers took it during pregnancy; emergency hysterectomies saved many of the daughters' lives, but at a terrible cost. PCBs, highly effective lubricants and insulators used in electrical capacitors, transistors, hydraulic fluids, plasticizers, inks, waxes and adhesives, were deforming and killing birds and fish; by 1971, Monsanto had voluntarily stopped making them. Each of these problems was seen as an isolated case: A few rogue chemicals had wreaked havoc, but havoc could be contained. Ban DDT, ban DES, ban PCBs -- perhaps we couldn't undo the damage already done, but we thought we could stop it in its tracks and breathe a sigh of relief.
The average person still thinks about chemicals as single entities, and our system of federal regulation still decides on a case-by-case basis whether chemicals are safe enough to circulate in our world. But a paradigm shift is underway among some scientists, who have over the last 30 years quietly begun to wonder: By introducing so many substances that did not evolve along with living organisms over hundreds of millions of years, have we unwittingly initiated changes in our biology that may be damaging it profoundly?
