Exposure to endocrine (hormone) disrupting chemicals (EDC) results in approximately €150 billion ($162 billion) in health care costs in the European Union each year, according to panels of scientists tasked by the EU Commission to study their impact. “The shocking thing is that the major component of that cost is related to the loss of brain function in the next generation,” Philippe Grandjean, M.D. of Harvard University, one of the report’s authors, told the Guardian.

EDCs, contained in common household products such as detergents, disinfectants, furniture, plastics, and pesticides, interfere with the body’s hormone system either by mimicking naturally produced hormones, blocking hormone receptors in cells, or effecting the transport, synthesis, metabolism or excretion of hormones. These impacts can result in devastating effects on one’s health, including behavioral and learning disorders, such as Attention Deficit Hyperactivity Disorder (ADHD), birth defects, obesity, early puberty, infertility, cardiovascular disease, and childhood and adult cancers. Nearly 100 percent of people have detectable amounts of EDCs in their bodies, according to the introductory guide to EDCs published by the Endocrine Society and IPEN.

“Our brains need particular hormones to develop normally –the thyroid hormone and sex hormones like testosterone and oestrogen. They’re very important in pregnancy and a child can very well be mentally retarded because of a lack of iodine and the thyroid hormone caused by chemical exposure,” Dr. Grandjean explained to the Guardian.

Scientists analyzed the economic impact of a number of EDCs, including phthalates, bisphenol A (BPA), polychlorinated biphenyls (PCBs), dioxins, perfluoroalkyl compounds, as well as DDE and organophosphate and organochlorine pesticides. The work, Estimating Burden and Disease Costs of Exposure to Endocrine-Disrupting Chemicals in the European Union, was published in the Journal of Clinical Endocrinology and Metabolism.

In the analysis, the economic burden of EDCs was calculated based on a 1981 Institute of Medicine approach to assessing the contribution of environment factors in causing illness. Uncertainty in the analysis was addressed by using a weight-of-evidence characterization for probability of causation developed by the Intergovernmental Panel on Climate Change (IPCC), and an epidemiology model used by the World Health Organization.

In addressing whether complete certainty of causation is a necessary basis for analysis, the study makes note of a quote from Sir Austin Bradford Hill, a 20th century epidemiologist renowned for his work demonstrating the connection between lung cancer and cigarette smoking as well as developing criteria for determining causal associations. The author’s write, “In his widely cited work about the criteria for causation, Sir Austin Bradford Hill acknowledged the reality that ‘all scientific work is incomplete —were it be observational or experimental,’ noting that uncertainty ‘does not confer upon us a freedom to ignore the knowledge we already have, or to post-pone the action that it appears to demand at a given time.’”