Center researchers address environmental contaminants

Environmental contamination continues to gain attention in the scientific community. Here at the UW-Madison campus, WRPRC staff are involved in plans to develop a new Center for Developmental and Molecular Toxicology. The existing Environmental Toxicology Center submitted a grant toward this goal in February.

Scientists affiliated with the new center would, in part, study the effects of environmental contaminants on prenatal development, says Ted Golos, chair of the WRPRC's Reproduction and Development Research Group. There is pressing need to learn more about how contaminants affect organisms at all levels, from causing molecular and chemical impairments in developing fetuses to resulting in visible deformities.

Golos explains that our Center will be able to provide knowledge from people who aren't toxicologists but who may be able to shed new light on the biology of environmental contamination. "In my lab, we study gene activity in placental cells, so we have started collaborating with a few investigators to look at environmental contamination as it relates to placental biology."

Dioxin, for example, has been linked to reproductive impairments in adulthood. Dioxin, once used in coolants for electrical transformers, continues to persist in the environment and bioaccumulate up the food chain (as do PCBs, heavy metals and other industrial contaminants). Dioxin metabolites can bind to receptors that control gene ranscription in placental cells. Studies in the toxicology literature suggest that large doses of dioxin metabolites can change placental structure or even cause fetal death in animals. WRPRC scientists could help reveal the mechanisms by which dioxin operates. Environmentalists believe more knowledge such as this could spur legislators to enact tougher environmental cleanup and contamination prevention laws in the United States.

Lead is another pollutant of concern to staff at our Center. Nellie Laughlin at the Department of Psychology's Harlow Primate Lab is studying the effects of lead exposure during early development on neurobehavioral function over life span. "Nellie is exploring how lead exposure affects cognitive ability, attention, auditory function and other behaviors," Golos explains. "Through nonhuman primate studies, she has found that lead has deleterious effects on the auditory system, similar to what has been found in children." Thus, monkeys could become valuable models for developing new therapies to treat lead poisoning.

But again, as with many environmental contaminants, we still don't have a good grasp on what lead actually does at the cellular level. "Anyone can read in the paper that lower IQs are linked to lead exposure in children," Golos says. "But what we aim to find out is whether these children have lower intelligence because lead affects their overall brain development, or whether it primarily affects their auditory processing, hindering their ability to understand verbal instruction and thus perform well in school."