Suspicions of toxins arise partly because studies have found that disproportionate shares of children develop autism after they are exposed in the womb to medications such as thalidomide (a sedative), misoprostol (ulcer medicine) and valproic acid (anticonvulsant). Of children born to women who took valproic acid early in pregnancy, 11 percent were autistic. In each case, fetuses seem most vulnerable to these drugs in the first trimester of pregnancy, sometimes just a few weeks after conception.

So as we try to improve our health care, it’s also prudent to curb the risks from the chemicals that envelop us. Senator Frank Lautenberg of New Jersey is drafting much-needed legislation that would strengthen the Toxic Substances Control Act. It is moving ahead despite his own recent cancer diagnosis, and it can be considered as an element of health reform. Senator Lautenberg says that under existing law, of 80,000 chemicals registered in the U.S., the Environmental Protection Agency has required safety testing of only 200. “Our children have become test subjects,” he noted.

One peer-reviewed study published this year in Environmental Health Perspectives gave a hint of the risks. Researchers measured the levels of suspect chemicals called phthalates in the urine of pregnant women. Among women with higher levels of certain phthalates (those commonly found in fragrances, shampoos, cosmetics and nail polishes), their children years later were more likely to display disruptive behavior.

Frankly, these are difficult issues for journalists to write about. Evidence is technical, fragmentary and conflicting, and there’s a danger of sensationalizing risks. Publicity about fears that vaccinations cause autism — a theory that has now been discredited — perhaps had the catastrophic consequence of lowering vaccination rates in America.

On the other hand, in the case of great health dangers of modern times — mercury, lead, tobacco, asbestos — journalists were too slow to blow the whistle. In public health, we in the press have more often been lap dogs than watchdogs.

At a time when many Americans still use plastic containers to microwave food, in ways that make toxicologists blanch, we need accelerated research, regulation and consumer protection.

“There are diseases that are increasing in the population that we have no known cause for,” said Alan M. Goldberg, a professor of toxicology at the Bloomberg School of Public Health at Johns Hopkins University. “Breast cancer, prostate cancer, autism are three examples. The potential is for these diseases to be on the rise because of chemicals in the environment.”

The precautionary principle suggests that we should be wary of personal products like fragrances unless they are marked phthalate-free. And it makes sense — particularly for children and pregnant women — to avoid most plastics marked at the bottom as 3, 6 and 7 because they are the ones associated with potentially harmful toxins.