Many common chemicals put the brain development of fetuses and children of all ages in danger, says a report backed by dozens of scientists, health practitioners, and children's health advocates.
The chemicals causing the most concern include lead and mercury, organophosphate pesticides (used in agriculture and home gardens), phthalates (found in pharmaceuticals, plastics, and personal care products), flame retardants, and air pollutants created by wood and fossil fuels. Also of concern are polychlorinated biphenyls or PCBs. Although they were banned in 1977, they can persist in the environment for decades, says Susan Schantz of the University of Illinois.
"These chemicals are pervasive, not only in air and water, but in everyday consumer products that we use on our bodies and in our homes," she said. "Reducing exposures to toxic chemicals can be done, and is urgently needed to protect today's and tomorrow's children."
"The human brain develops over a very long period of time, starting in gestation and continuing during childhood and even into early adulthood," Schantz continued. "But the biggest amount of growth occurs during prenatal development. The neurons are forming and migrating and maturing and differentiating. And if you disrupt this process, you're likely to have permanent effects."
Many studies have shown that some of the chemicals in question, such as phthalates, interfere with normal hormone activity. Most pregnant American women will test positive for exposure to phthalates which disrupt thyroid hormone function.
"Thyroid hormone is involved in almost every aspect of brain development," said Schantz. "It regulates many of the genes involved in nervous system development."
Studies have linked exposure to certain phthalates with attention deficits, lower IQ, and conduct disorders in children. "Phthalates are everywhere; they're in all kinds of different products. We're exposed to them every day," Schantz said.
The report criticizes current regulatory policies that allow chemicals to be introduced into people's lives with little or no review of their effects on fetal and child health.
"For most chemicals, we have no idea what they're doing to children's neurodevelopment," Schantz said. "They just haven't been studied.
"If it looks like something is a risk, we feel policymakers should be willing to make a decision that this or that chemical could be a bad actor and we need to stop its production or limit its use," she said. "We shouldn't have to wait 10 or 15 years — allowing countless children to be exposed to it in the meantime — until we're positive it's a bad actor."
The new report is published in the journal
Environmental Health Perspectives.