A third study randomized 23 pregnant rats to low levels of a mix of polychlorinated biphenyls (PCBs) and 22 to an inactive substance. Researchers found that these EDCs disrupted five genes that are critical to the normal hypothalamic control of reproduction. Compared with the control group, the EDC group showed delayed puberty in male offspring and disrupted reproductive cycles in adult female offspring.
The data collectively suggest that determinations of the potential risks or safety of any EDCs should be particular to specific age groups, Dr. Park said.
The EDCs identified so far are just the tip of the iceberg, she added. "Many more chemicals will be found" to be EDCs, she predicted.
Many products contain EDCs. Phthalates are part of some vinyl floor tiles, toys, blood transfusion bags, medical tubing, perfumes, lotions, cosmetics, air fresheners, laundry products, and more. BPA is found in many hard plastic bottles, cash register receipts, and the epoxy resin that lines canned goods. PCBs had been used in plastics, floor finishes, and electrical equipment before being banned in 1979 but are still present in air, water, and soil.
Tools for Clinicians
Dr. Gore and Dr. Taylor recommended these resources for clinicians who are wondering what and how to advise patients about EDCs in their environment:
• The Collaborative on Health and the Environment.
• Environment and Human Health.
Some other resources are available from the University of California's program on reproductive health and the environment.
The speakers reported having no relevant financial disclosures.