Study shows diet can be major source of chemical exposures


Your water bottle may have a BPA-free label, and you try to avoid cooking food in plastic containers. But you may still be exposed to chemicals in the food you eat, even if you’re eating an organic diet and your meals are cooked and stored in non-plastic containers, according to a study published February 27 in the Nature Journal of Exposure Science and Environmental Epidemiology.

Children may be most vulnerable because they tend to eat higher fat foods, such as dairy, which can have high concentrations of phthalates. Spices can also have high concentrations of phthalates.

Randomized dietary study design

Researchers compared the chemical exposures of 10 families during a five-day period. Half of the families were given written instructions on how to reduce phthalate and BPA exposures. The other families received local, fresh, organic food—including snacks, milk and fruit—that was not prepared, cooked or stored in plastic containers.

Researchers tested the urinary concentrations of metabolites for phthalates and BPA, and they got surprising results. They expected the levels of the metabolities to decrease in those adults and children eating the catered diet.

Instead, the opposite happened. The urinary concentration for phthalates were 100-fold higher than the levels found in the majority of the general population—a comparison that comes from a study conducted by the Centers for Disease Control and Prevention.

“It’s difficult to control your exposure to chemicals, even when you try,” said Sheela Sathyanarayana, MD, MPH, lead author on the study and an environmental health pediatrician at Seattle Children’s Research Institute and in the University of Washington School of Public Health. “Exposures to chemicals often occur during the food production process,” she added.

What are phthalates, bisphenol A?

Phthalates and BPA (bisphenol A) are synthetic endocrine-disrupting chemicals used in industrial and consumer products, including water and baby bottles, sunglasses, DVDs and sports equipment. Previous studies have linked prenatal exposure to phthalates with abnormalities in the male reproductive system. Associations have also been shown between fetal exposure to BPA and hyperactivity, anxiety, and depression in girls.

EPA limits for contaminants

Using the study results, the researchers estimated that the average child aged three to six years old was exposed to 183 milligrams per kilogram of their body weight per day. The U.S. EPA’s recommended limit is 20 mg/kg/day.

“We have very little control over what’s in our food, including contaminants,” said Sathyanarayana. “Families can focus on buying fresh fruits and vegetables, foods that are not canned and are low in fat, but it may take new federal regulations to reduce exposures to these chemicals.”

Concentrations for families returned back to baseline after the intervention ended. Sathyanarayana and team aim to conduct additional studies with more participants. In the meantime, families can make a difference by following the tips below.

Protecting yourself, your family from contaminations in food: Dr. Sathyanarayana’s tips for parents

• Buy fresh fruits and vegetables, and foods that are low in fat
• Avoid canned foods
• Do not microwave food or beverages in plastic containers
• Do not place plastics in the dishwasher
• Follow the saying “everything in moderation,” and don’t over-do it on dairy products including butter, cream, milk and cheese

Co-authors on the dietary study

Co-authors on the study include Garry Alcedo (Seattle Children’s Research Institute), Brian E. Saelens and Chuan Zhou (Seattle Children’s Research Institute, UW Department of Pediatrics), Russell L. Dills and Jianbo Yu (UW Department of Environmental and Occupational Health Sciences) and Bruce Lanphear (BC Children’s Hospital and Simon Fraser University).

The study was funded by the Center for Ecogenetics and Environmental Health and the Pediatric Environmental Health Specialty Unit in the Department of Environmental and Occupational Health Sciences in the School of Public Health at the University of Washington (grant number ES007033, NIEHS).


Phthalates—U.S. Environmental Protection Agency

Reproductive health providers should discuss environmental exposure risks with patients, March 5, 2012

Protecting children from chemicals

Northwest Pediatric Environmental Health Specialty Unit, University of Washington (Click on fact sheets in left column for additional tips)


If you’d like to arrange an interview with Dr. Sathyanarayana, please contact Children’s PR team at 206-987-4500 or at [email protected]