Last week, researchers found a host of toxic chemicals in the bodies of pregnant women throughout the U.S. Industry reps quickly trotted out their favorite messages in response: "Chemicals are a fact of modern life," "just because toxins are in your body doesn't mean they'll hurt you," and "the levels are too low to matter - researchers have new tools that can measure extremely low levels."

The fact is, low levels of chemicals in the womb can matter a whole lot. And studies like last week's make the chemical industry very, very nervous.

Researchers from UC San Francisco dug into samples collected by the Centers for Disease Control that measured environmental contaminants in thousands of people across the country. They found that the 250 pregnant women sampled carried many of the 163 pesticides and other chemicals measured, often at levels linked to "adverse reproductive and developmental outcomes" in other studies. Their sobering findings were published in Environmental Health Perspectives. As Greenwire reports:

. . . the study found that between 99 and 100 percent of sampled pregnant women carried chemicals in the organochlorine family of pesticides, the rocket fuel additive perchlorate, the plastic softeners phthalates, polycyclic aromatic hydrocarbons (PAHs), and perfluorinated compounds -- often used in nonstick cookware.

Pesticides and rocket fuel in the womb? The chemical industry should be nervous. Common sense tells us that being exposed to toxic chemicals during pregnancy can't be good for either mother or child. And science tells us the exact same thing. A pregnant woman's biological systems are working overtime, with her finely tuned hormone system managing the complex process of fetal development. Miniscule amounts of chemicals that look like hormones to the body can throw a serious wrench in the works.

An infant is even more vulnerable, as exposure to the wrong chemical while physiological systems are being created can have impacts that last a lifetime. The scientific literature is chock full of studies showing the impacts of contaminants on fetal development. One recent study confirmed that many chemicals pass "efficiently" from mother to child during pregnancy. I've found that the best way to truly understand both the process and the stakes is to dive into author Sandra Steingraber's book Having Faith, where she chronicles her own journey through pregnancy and breastfeeding with an eye toward how chemicals might impact her child at every stage.

The chemical industry keeps trying to convince us not to worry about all those chemicals in our bodies, but the science emphatically tells us otherwise. Sandra's book was published back in 2001, and the science on harms of low-level exposure to chemicals during fetal development is even stronger today. The good news: there's momentum building across the country to do what it takes to fix the system we've set up to manage these toxic chemicals. The sooner the better.

This post appeared previously at GroundTruth.org.