Exposure to Perchlorate in Womb Linked to Lower IQ

High levels of an environmental contaminant in pregnant women may lower the intelligence quotient, or IQ, of their children, a new study has found.

The study was conducted by researchers at the Boston University School of Medicine (BUSM) and the Cardiff University.

The contaminant, called perchlorate, is present in low amounts in all of us. The chemical is also found in bleach and in some fertilizers and is even used to produce rocket fuel, fireworks and explosives.

Perchlorate can disrupt functions thyroid's ability to produce hormones, which lead to poor physical and mental development, according to the US Environmental Protection Agency

"The reason people really care about perchlorate is because it is ubiquitous. It's everywhere," Dr. Elizabeth Pearce, MSc, associate professor of medicine at BUSM, said, according to a news release. "Prior studies have already shown perchlorate, at low levels, can be found in each and every one of us."

For the study, the researchers used data from the Controlled Antenatal Thyroid Study (CATS) cohort. The team chose 487 mother-child pairs from women with underactive thyroid gland. The researchers found that 50 women with the highest level of perchlorate had children with below-average IQ, showing that the chemical affects brain development.

The study is published in the Journal of Clinical Endocrinology & Metabolism. The Wellcome Trust and Compagnia de San Paulo, Turin, funded the research. And while researchers suspect a link between the chemical perchlorate and IQ, they have not established a cause-and-effect relationship, and further study is needed before they can do so.

Previous studies have found a link between disruption in thyroid function in pregnant mothers and hypothyroidism in newborns. An underactive thyroid in young babies can lead to several health problems and even low intelligence levels.

EPA had announced in 2011 that it has set a federal drinking water standard for the chemical.