"University of Michigan researchers conducted a large-scale, human study that's found exposure to chemicals found in household plastics -- Bisephenol-A (BPA) and phthalates -- reduces thyroid function, confirming the findings of many smaller studies. Lead researcher John Meeker found that the more BPA and phthalates that were in people's bodies, the more likely they were to show impaired thyroid function. People who who showed the highest 20% of exposure also showed up to 10% more thyroid function impairment than those with the 20% lowest exposure."
"Large Study Confirms BPA-Thyroid Function Link"
Source: Mother Jones, 07/12/2011