NOVEMBER 2010
                                        

Center to study effects of plastics chemicals on children’s health

A new research center based at the University of Illinois will investigate whether regular exposure to bisphenol A (BPA) and phthalates – chemicals widely used in plastics and other consumer products – can alter infant and adolescent development, cognition or behavior.

A $2 million grant from the National Institute of Environmental Health Sciences at the National Institutes of Health and the United States Environmental Protection Agency will establish the Children’s Environmental Health and Disease Prevention Research Center at Illinois. Four pilot projects will be conducted over the next three years at Illinois and Harvard University.

BPA and phthalates are endocrine disruptors. They mimic natural hormones and thus can interfere with hormone signaling in the body.

BPA is used to make shatterproof plastics and is a component of many containers and bottles, PVC pipes, dental fillings and electronics. Resins made with BPA line metal food and drink containers. Human studies have found BPA in many tissues and fluids, including urine, blood, breast milk and the amniotic fluid of pregnant women.

The National Toxicology Program conducted a review of laboratory studies on animals exposed to BPA in 2008 and reported that while there was little evidence that exposure to BPA was harmful to adults, there was “some concern for effects on the brain, behavior and prostate gland in fetuses, infants and children at current human exposures to bisphenol A.”

Phthalates increase the durability, transparency and flexibility of some plastics. They also are used as emulsifiers, lubricants, stabilizers, binders and coatings in cosmetics, building materials, food products, wrappers, textiles, toys and pills. Studies have found that high exposure to some phthalates can alter hormone levels and cause birth defects in rodents.

The four pilot projects will evaluate the effects of BPA and phthalate exposure on infants and adolescents. Two of the projects will focus on human subjects, and two will involve rodents.

The centerpiece of the studies is a project that looks at exposure to BPA and phthalates in relation to the physical and mental development of infants. Carle Physicians Group in Champaign-Urbana will collaborate on this project, called Illinois Kids (I-Kids). The researchers will follow pregnant women and their babies, measuring BPA and phthalate levels in the urine every month and collecting data on possible sources of exposure. The babies will also undergo physical, behavioral and cognitive tests.

“We’re going to see the babies within the first 24 hours of birth and collect a lot of data about their growth and development but also about their cognitive function,” said Susan Schantz, a professor of comparative biosciences at Illinois, an environmental toxicologist and the director of the new center.

“These chemicals are endocrine disrupters,” she said. “BPA is estrogenic and phthalates are anti-androgenic, so both are expected to disrupt sex hormones in the body.”

Testosterone and estrogen are important for the sex differences that develop in the fetal and neonatal brain. Male and female babies normally differ in their physical attributes and also in their cognitive abilities and behavior, Schantz said. “We want to see if those sex differences are changed by the exposure to these chemicals,” she said.

Two developmental psychologists at Illinois, comparative biosciences professor Andrea Aguiar and psychology professor Renee Baillargeon, will conduct the cognitive and behavioral tests. The researchers hope to follow the infants for many years.

In a separate project, a collaborator at Harvard Medical School, Susan Korrick, M.D., will assess the BPA and phthalate exposures of a group of adolescents she has been following since they were born.

Korrick will conduct neuropsychological assessments of her subjects and measure traits, such as verbal or spatial reasoning, known to differ between males and females at this age.

“Adolescence is another period where sex hormones have a big impact on brain development and behavior and even physical development,” Schantz said. This project will allow researchers to determine if exposure to BPA and phthalates hinders normal hormone signaling and alters the development of traits that differ between the sexes.

Illinois psychology professor Janice Juraska will conduct similar studies in rats exposed to the same chemicals “at time periods in the rats’ lives that parallel prenatal development and adolescence in humans,” Schantz said. Juraska will evaluate cell density in various brain regions to get a fuller picture of any changes that accompany exposure to the chemicals.

A fourth project will look at potential changes in the reproductive systems of male and female mice exposed to BPA and phthalates. Illinois comparative biosciences professor Jodi Flaws, a reproductive toxicologist and associate director of the new center, and National Institute of Environmental Health Sciences researcher Humphrey Yao, a reproductive biologist, will use genetically altered mice to reveal the mechanisms by which these hormone mimics act on reproductive cells.

“Investigators from all four projects will work together closely to obtain a cohesive picture of the effects of bisphenol A and phthalates on infant and adolescent development, cognition, and behavior,” Flaws said.

A key focus of the center will be education and outreach to the community.