Dr. Jerome Groopman, a professor of medicine at Harvard and writer for The New Yorker, is careful in his piece, "The Plastic Panic," about the toxicity of common chemicals in our environment, to examine evidence on both sides of the debate.
Still, while there remains no conclusive proof that chemicals such as bisphenyl A (BPA) and other compounds cause cancer or interfere with normal development, Groopman's conclusion is clear: "...their increasing prevalence and a number of human studies that associate them with developmental issues have become too worrisome to ignore," he writes. "The challenge now is to decide a course of action before there is any certaintly about what is truly dangerous and what is not."
Indeed, much of Groopman's article is truly scary, particularly for parents of young children. For instance, in 2001, the E.PA banned the sale of the pesticide chlorpyrifos, known as Dursban, for residential and indoor use but it is still used in agriculture and farming. Groopman writes:
In 2004, the Columbia group published results in the journal Environmental Health Perspectives showing that significant exposure during the prenatal period to chlorpyrifos was associated with an average hundred-and-fifty-gram reduction in birth weight—about the same effect as if the mother had smoked all through pregnancy. Those most highly exposed to the insecticide were twice as likely to be born below the tenth percentile in size for gestational age. The researchers found that children born after 2001 had much lower exposure levels—indicating that the ban was largely effective.
For those children who were exposed to the pesticide in the womb, the effects have seemed to persist. The children with the greatest exposure were starting to fall off the developmental curve and displayed signs of attention-deficit problems by the time they were three. By seven, they showed significant deficits in working memory, which is strongly tied to problem-solving, I.Q., and reading comprehension. Another study, published this month in Pediatrics, using a random cross-section of American children, showed that an elevated level of a particular pesticide residue nearly doubled the likelihood that a child would have A.D.H.D.
Virginia Rauh, the leader of Columbia’s research, said: “Such a decline can push whole groups of children into the developmentally delayed category.”
And here's more:
Beginning in 2003, Antonia Calafat, a chemist at the Centers for Disease Control and Prevention, and Russ Hauser, of the Harvard School of Public Health, set out to evaluate the exposure of premature infants to certain environmental contaminants. The researchers hypothesized that infants treated in the most intensive ways—intravenous feedings and delivery of oxygen by respirators—would receive the most exposure, since chemicals like phthalates and BPA can leach from plastic tubing. They studied forty-one infants from two Boston-area intensive-care units for BPA. Calafat told me, “We saw ten times the amounts of BPA in the neonates that we are seeing in the general population.” In several children, the levels of BPA were more than a hundred times as high as in healthy Americans.
Calafat, who came to the United States from Spain on a Fulbright scholarship, developed highly accurate tests to detect BPA, phthalates, and other compounds in body fluids like blood and urine. This advance, she explained, “means that you are not simply doing an exposure assessment based on the concentration of the chemicals in the food or in the air or in the soil. You are actually measuring the concentrations in the body.” With this technology, she can study each individual as if he or she were a single ecosystem. Her studies at the Centers for Disease Control show that 92.6 per cent of Americans aged six and older have detectable levels of BPA in their bodies; the levels in children between six and eleven years of age are twice as high as those in older Americans.
This program aired on May 26, 2010. The audio for this program is not available.