Unfortunately, consumers have no way of knowing which products or brands contain phthalates because manufacturers themselves don't know whether their processing materials contain phthalates, Sathyanarayana added.
Brent Collett and his wife and kids were one of the families that received the catered diet for Sathyanarayana's study. At the end of the study, Collett and the other families received a letter telling them their phthalate and BPA levels and the foods that contained phthalates.
"To have ingredients [such as coriander] that is not a major part of diet lead to this increase was a bit of an eye-opener," said Collett, a psychologist at Seattle Children's Hospital. "There would be no way we as consumers could do any better" than the catered diet in this study at avoiding plastics, he added.
The American Chemistry Council, which represents the chemicals industry, had this to say about the findings:
"The study confirms that exposure to BPA is very low, regardless of the dietary choices made by the participants," said Steven Hentges, executive director of the Polycarbonate/BPA Global Group at the council. "The exposure values reported are below the typical values for the U.S. population . . . The study results are very reassuring, and don't raise any alarms for BPA."
But another expert had a different opinion.
Dr. Maida Galvez, an associate professor of pediatrics and preventive medicine at the Icahn School of Medicine at Mount Sinai University in New York City, said: "This study points to the need for comprehensive legislation, such as the Safe Chemicals Act, and for third-party certification that products are free [of phthalates and BPA]."
The Safe Chemicals Act is proposed legislation that would require manufacturers to provide safety data for chemicals in products that are already on the market, and help ensure that products are tested for safety before they enter the market.
Phthalates and BPA are found in a variety of other materials, including construction and automobiles, medical devices, perfumes and clothing.
The U.S. Food and Drug Administration approved phthalates for use in food packaging back in the 1960s, and has not reevaluated their safety since then, said Dr. Sarah Janssen, a senior scientist in the Health and Environment program of the Natural Resources Defense Council, an environmental action group.