A new study by a Columbia economist definitively links a decline in fetal harm in the 1990s to stricter environmental controls. It proves, according to its authors, that living near a toxic manufacturing plant poses a significant risk to fetal health.

The study, by Professor Janet Currie and graduate student Johannes Schmieder, will be published in the May edition of the American Economic Association's Papers and Proceedings. Currie's research specializes in the relationship between economic policy and children's health.

Professor Janet Currie Image credit: Eileen Barroso

The data on toxic releases are collected as a result of a 1986 federal law requiring many U.S. plants to file annual emissions reports with the Environmental Protection Agency—a law created in response to the 1984 disaster in Bhopal, India, where more than 10,000 people were killed after a Union Carbide pesticide plant released 42 tons of toxic gas.

Currie has since capitalized on those emissions reports to produce research that is "revolutionary," says Michael Greenstone, an environmental economist at Massachusetts Institute of Technology. "This paper has taken a giant step forward in improving our understanding of the relationship between toxic emissions and infant health," he says.

Currie's work is an outgrowth of her research interest in children's welfare, where she has used economic approaches and data to study such topics as pollution, school absenteeism and the effects of school breakfast programs on child nutrition. Her 2006 book, The Invisible Safety Net: Protecting Poor Children and Families, looks at social welfare programs and determines that—contrary to much political rhetoric—many social welfare programs are effective.

A few years ago, Currie noticed that the emissions data collected by the EPA hadn't been fully explored since 1986. While there had been plenty of research on the effects of chemical emissions following the Bhopal disaster, none of it focused on the health of infants born near manufacturing plants, she recalled. Fetal health, she reasoned, would be an ideal way to measure the effects of toxic emissions because of the known timeframe of pregnancy, a restriction that would allow for tighter control of variables such as place of residence.

Currie relied on vital statistics data, including birth certificates, as well as the mandatory emissions reports from plants in the top 75 percent of U.S. counties by population from 1988 to 1999. She considered only the births from January to March of each year and matched that data with emissions reports from the previous year. (Babies born in the first three months of the year are more than 50 percent likely to have been exposed to the previous year's emissions while in the womb, she explains.)

Currie's previous work has helped shape policy for federal children's programs, like State Children's Health Insurance Program and Head Start. She hopes her newest research will encourage environmental change in the coming years as well.

"The ultimate goal of this work on toxic exposure is to understand the vulnerabilities of children and how we can protect them," she says. "Children with low birth weight are less likely to graduate from high school and more likely to have attention deficit disorder. It's not true that everyone starts on a level playing field."