"Safer" chemicals in plastics may be hazardous to kids

Two chemicals used to strengthen common household items like plastic wrap and processed food containers have been linked to high blood pressure and diabetes in children, according to a new series of studies.

Ironically, the two compounds, di-isononyl phthalate (DINP) and di-isodecyl phthalate (DIDP) -- both in a class of chemicals known as phthalates -- were introduced about a decade ago as "safer" replacements for another chemical, di-2-ethylhexylphlatate, or DEHP, which previous research proved had similar adverse effects.

Researchers from NYU Langone Medical Center analyzed blood and urine samples of children and adolescents who participated in the National Health and Nutrition Examination Survey. The results showed what they call a "significant association" between DINP and DIDP concentrations and high blood pressure. They also found an association between the presence of the chemicals and increased insulin resistance, a precursor to diabetes.

While the American Chemistry Council defended use of the phthalates, Dr. David Agus told "CBS This Morning" that there's an oversight issue among the federal agencies that regulate the manufacturing of these products, including the Food and Drug Administration.

"There's this notion that they only react when there's a problem," he said. "It's innocent until proven guilty and that's an issue."

Lead study author Dr. Leonardo Trasande also called for more testing to be done before chemicals are put into products.

"Our study adds further concern for the need to test chemicals for toxicity prior to their broad and widespread use, which is not required under current federal law (the 1976 Toxic Substances Control Act)," he said in a statement.

The study only shows an association and does not prove the chemicals actually caused the health conditions observed.

But experts still recommend consumers take precautions to limit exposure to phthalates and ensure the health of their families.

If food comes in a plastic takeout container, "take it and put it into a glass container at home," Agus said. "Don't put it in the microwave or into the dishwasher, which can make these chemicals leach out."

Trasande also recommends using other alternatives like wax paper and aluminum wrap and checking the bottom of plastic containers for the numbers 3, 6 or 7 inside the recycle symbol. This indicates chemicals such as phthalates were used in manufacturing the product.

Joseph Perrone, Chief Scientific Officer for the Center for Accountability in Science, pointed out that other factors could have been to blame for the link between chemicals in plastics and diabetes and high blood pressure. Here is a summary of his view:

"Before companies can use any chemicals that may come into contact with food, the U.S. Food and Drug Administration reviews them for safety. Just last year, the European Commission, which sets strict standards for chemical safety, re-evaluated the phthalates DINP and DIDP and concluded that they are safe in 'all current consumer applications.'

The two new studies cited by CBS News that explore the link between phthalates and increased blood pressure and insulin-resistance have significant limitations. The authors admit that their finding that children with higher levels of phthalates in their urine is associated with a higher blood pressure and insulin resistance could be explained by other factors -- notably that children who eat more processed packaged food (and thus are exposed to higher levels of phthalates) could have higher blood pressure and insulin resistance because of poorer diet, not because of phthalates. The studies neither explore how these children were exposed to phthalates nor show that phthalates actually cause health problems.

Additionally, the phthalates explored by these studies, DINP and DIDP, are also not typically used in microwavable plastic, though viewers were advised to avoid microwaving plastic. Even the most health-conscious viewer should fear neither increased exposure to these phthalates simply by microwaving their food in microwave-safe plastic containers nor exposure to these phthalates from other sources."