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CEEH Junior Investigator Sheela Sathyanarayana presented "Endocrine Disrupting Chemicals: Translation from Research to Prevention" at the monthly Partnerships for Environmental Public Health (PEPH) webinar on October 24th. Dr. Sathyanarayana, a pediatrician, environmental health specialist, and Co-Director of the UW Northwest Pediatric Environmental Health Specialty Unit (PEHSU), studies the effect of prenatal phthalate exposure on birth outcomes.
Children are the most vulnerable to adverse health effects from exposure to endocrine disrupting chemicals such as phthalates and bisphenol A (BPA). Phthalates are anti-androgens; prenatal exposure is associated with abnormalities of the male reproductive tract. BPA is an estrogen; prenatal exposure in animals is associated with breast and prostate tumors, and with metabolic changes that lead to obesity.
We have known for several years that phthalates and BPA, both used in the manufacture of plastics, can leach from flexible tubing, vinyl flooring, squeezable plastic toys, vinyl gloves, and carbonless register receipts. But recent studies suggest the largest source of phthalate and BPA exposure in humans is through the food supply. Canned food, processed food, meat, and dairy products are exposed to BPA and phthalates during processing. Cans may be lined with plastic that contains BPA; dairy products have higher concentrations of phthalates than other foods. Dr. Sathyanarayana suggests that milk is exposed to phthalates as it passes through flexible tubing and plastic storage containers during processing. She believes most phthalate and BPA exposure in food occurs in processing and packaging, before consumers bring it home.
A CEEH pilot grant awarded to Dr. Sathyanarayana supported a study that compared two interventions aimed at reducing exposure to phthalates and BPA. Ten families with young children participated. The first intervention was to provide each family with a week’s diet of catered fresh local foods; the second intervention was to provide a fact sheet describing ways to avoid exposure to phthalates and BPA in the diet, and encouraging participants to follow these suggestions. Urine phthalate and BPA concentrations were measured before, during, and after the intervention. The results? There was no change in urinary phthalate or BPA in the group given the fact sheet. Unexpectedly, urinary concentration of phthalates and BPA increased (P<.001) in the group who ate a catered fresh diet. Further investigation of the ingredients in the catered food identified contamination of a spice used in the preparation of some of the meals. Webinar participants were curious about what the spice was. Dr. Sathyanarayana reported that spices in general contain the same concentrations of phthalates as other foods and opined that the contamination was a fluke. Then she revealed that the contaminated spice was brown coriander. She asserted that evidenced-based and practical interventions are needed to reduce exposure, and suggested that federal regulation may be the only way to control contamination of the food supply by phthalates and BPA.
Sathyanarayana's CEEH pilot project led to the NIEHS-supported TIDES (The Infant Development and the Environment) Study, a 3-site, 5-year longitudinal study assessing phthalate exposure in pregnant women and the effect on their offspring.
PEHSU Factsheets provide information to health care providers and the public about ways to reduce exposure to phthalates and BPA.