Oct. 24, 2011 -- Preschoolers exposed to higher levels of bisphenol A (BPA) in the womb may have more anxiety and depression and have worse self-control than those exposed to lower levels of the chemical before birth, a new study shows.

The chemical is found in a wide array of consumer products, including plastic bottles, food packaging, dental sealants, and the heat-activated paper that's used to print cash register receipts.

A spokesman for an industry group says the new study had flaws in its design, and that other studies have found BPA to be safe.

The chemical structure of BPA is similar to the hormone estrogen. That raises concerns that constant exposure could have biological effects, particularly for developing babies and young children.

Studies of animals exposed to BPA have found changes in the brain, behavior, and abnormal development of reproductive organs. So far, there has been less evidence of health effects in humans.

The new study is published in Pediatrics. It is one of the first to show that BPA exposure in the womb may be linked to behavioral effects in young children.

Researchers caution though that their study was only able to show associations between BPA and behavior. It did not prove cause and effect.