Rice psychology class probes pollution, early development links

Rice psychology class probes pollution, early development links

BY FRANZ BROTZEN
Rice News Staff

As the fifth most-polluted city in the U.S., Houston is a great place to study the effects of pollutants on early childhood development. So when Jim Dannemiller decided to teach Pollution and Psychological Development (PSYC 480) for the first time, he knew he would have a veritable laboratory in which his students could carry out their experiments.

Dannemiller, the Lynette S. Autrey Professor of Psychology and director of Rice’s Neurosciences Program, said Houston has the heavy industry, vehicle density and proximity to the ocean that account for much of the toxins that affect children, and it also has a research infrastructure that has broad experience investigating those effects. As an example, Dannemiller cited the Pediatric Lead Clinic at Ben Taub General Hospital, and in particular, Winifred Hamilton, director of environmental health at Baylor College of Medicine, who has studied the high levels of lead in the blood of children growing up in Galveston.

JIM DANNEMILLER

Students in the course being taught this spring are reading “Silent Scourge: Children, Pollution, and Why Scientists Disagree” by C.F. Moore. As the title implies, there are different interpretations of how different types and quantities of pollution affect humans as well as the environment. The goals of the course include learning how attitudes, beliefs and values affect policies related to pollution, in addition to learning about some of the ways in which environmental hazards influence psychological functioning and development. The course will be offered again this summer.

Many effects of pollutants are well-known. Mercury poisoning, for instance, causes a reduction in children’s learning abilities, delays in walking and talking and a decrease in attention or memory. One method Dannemiller plans to use in the future to study children who have been exposed to pollution prenatally is by measuring visual attention of 2- and 6-month-old babies by eye-movement tests and comparing them to a control group.

The juniors and seniors in the course are looking at five specific sources of pollution: lead, mercury, polychlorinated biphenyls (PCBs), pesticides and noise.

The main source of lead ingested by Americans used to be gasoline. It was added to boost octane levels, but was gradually eliminated in the 1970s. Lead was also commonly used in house paints and continues to affect children in older dwellings. This pollutant is particularly dangerous because once it is ingested, it remains in a person’s system forever. 

PCBs were used to insulate electrical transformers until they were banned 30 years ago because of their high toxicity. Dumping of PCBs in the Hudson River and the Great Lakes led to contamination of fish stocks and still affects the water to this day.

“What it generally takes to get people’s attention is an acute poisoning episode,” Dannemiller said, pointing to the famous mercury poisoning case in Minamata, Japan, which came to light in 1956. Like PCBs, the mercury was dumped into the water and accumulated in fish and shellfish, which were eaten by people. Thousands were poisoned; hundreds died. The incident caused an uproar and raised awareness of mercury poisoning.

The impact of such serious cases is well-documented, Dannemiller said, but what happens at low levels of contamination? “Is there any safe level?” he asked. Students in PSYC 480 rely on their backgrounds in developmental psychology and statistics to weigh the effects of pollutants when those effects are more subtle.

Dannemiller also encourages students to consider “the social inequities in exposure to these elements,” since the poor tend to be more exposed to things like lead paint and PCB-tainted landfills than the rich. “These are questions of social justice,” he said.

While some steps have been taken to limit exposure to pollutants like lead and mercury (try finding a mercury-filled thermometer at the drugstore these days), Dannemiller cautioned that new hazards may pose future risks. New technology — like the government-mandated compact fluorescent light bulbs that contain small amounts of mercury, rather than tungsten found in incandescent bulbs — could cause problems when people throw away broken bulbs in their trash. And problematic organic compounds like bisphenols, which are used in some plastics, may have physiological consequences.

Teaching PSYC 480 has changed some of Dannemiller’s habits. He said he has been made aware of issues like how to get rid of mercury in a responsible way and being conscious of potential pollutants in the food supply. Noting that large predators accumulate more mercury than their smaller prey, he said, “I have changed the types of seafood that I eat.”