The bad news about the chemical bisphenol A (BPA) is getting worse. BPA, which is used to make certain plastics, was banned from use in the manufacture of baby bottles and sippy cups by the U.S. Food and Drug Administration.

Now a study of over 3,000 children and adolescents, ages 6 through 19 years, has found a close link between obesity in children and adolescents and the levels of BPA in their urine.

Among those with the highest BPA levels, 22.3 percent were obese, versus 10.3 percent of those with the lowest levels.

"This is the first association of an environmental chemical in childhood obesity in a large, nationally representative sample," lead investigator Leonardo Trasande, associate professor of pediatrics and environmental medicine at New York University Medical Center, told TheDoctor. He went on to explain that previous studies looked at the connection between BPA concentrations in the urine of adults and obesity. Trasande also pointed out that children are uniquely vulnerable to the effects of environmental chemicals.

The researchers randomly selected subjects from the 2003-2008 National Health and Nutrition Examination Study, noting their urinary BPA concentrations. They found that children with the highest levels of urinary BPA were over twice as likely to be obese as those with the lowest concentrations of urinary BPA. Among those with the highest BPA levels, 22.3 percent were obese, versus 10.3 percent of those with the lowest levels.

Trasande went on to say that longer-term, population-based studies are needed using data from younger children who are more likely to be affected by BPA. As a low grade estrogen, BPA disrupts the body’s metabolic processes. However, last year the FDA declined to forbid the use of BPA to line aluminum cans and in other food packaging, where manufacturers maintain that it serves an antiseptic function.

“Our study suggests that we need to consider environmental and chemical exposures as possible contributors to the obesity epidemic,” said Trasande. He also said that the findings would imply that the FDA needs to rethink its decision about not banning BPA in food packaging.

The study was published in the September 19 issue of the Journal of the American Medical Association, which was dedicated to t he topic of obesity.