A new study published in theJournal of Public Analysis and Managementhas found evidence that prenatal exposure to emissions from a Pennsylvania Power Plant in a large region of New Jersey downwind from the plant had an impact on the birth weight of infants. Researchers studied singleton births between 1990 and 2006, born to mothers living as far as 20-30 miles downwind from the plant. They found that mothers living in that area were at a greater risk of giving birth to infants with low birth weight or very low birth weight, with increased likelihoods of up to 6.50 and 17.12%, respectively. Low birth weight is defined by weight less than 5 lbs, 8 oz and very low birth weight is defined as less than 3 lbs, 5 oz.

In order to determine causality, theresearchers saythey used “a unique identification strategy that is bolstered by scientific evidence on a specific upwind polluting source, provided by the downwind state and also verified by the U.S. Environmental Protection Agency (EPA).” These methods, they continue, are “potentially applicable to a wide range of studies examining the impact of upwind states’ power plant emissions, which have been the target of a series of environmental regulations, such as the EPA’s Cross-State Air Pollution Rule.”

This study illuminates the ways in which environmental regulations have little impact when implemented on a state-by-state basis. “While regulation of plant emissions predominantly occurs on a state-by-state basis, this regulatory structure can be ineffective in the case of cross-border emissions,” explain the authors to the Association for Public Policy Analysis and Management. “Indeed, the empirical setting of our study gives a realized, not hypothetical, example of transboundary power plant emissions that can remain uncontrolled for years when both the upwind and downwind states are required to be ‘good neighbors’ under the Clean Air Act.”