Though largely descriptive, mounting evidence suggests that exposure to air pollution may harm infant health, even in developed countries like the United States. Very recent evidence implies that a specific form of air pollution—fine particulate air pollution—may also have deleterious impacts on newborn babies. “Fine particles” are formed by sulphur dioxide (SO
2) and oxides of nitrogen (NO
x) emitted primarily from coal fired power plants and, until recently, this form of pollution was largely unregulated. In addition to these power plants producing harmful emissions locally, such emissions may cross state boundaries due to prevailing downwind air patterns. As a result, pregnant women in neighboring states may be harmed by the negative spillover effects of coal fired power plants. In 2005, the Environmental Protection Agency (EPA) implemented the Clean Air Interstate Rule (CAIR), a manifestation of the “good neighbor” provisions of the Clean Air Act, in order to limit emissions from power plants in the eastern United States that were found to interfere with the National Ambient Air Quality Standards (NAAQS) of other states. In essence, the CAIR sought to, and ultimately achieved, reductions in exposure to fine particulate matter in states neighboring their counterparts with coal fired power plants. We investigate the impacts the CAIR has had on infant health outcomes, including prematurity, birth weight and infant mortality.
We find evidence that reduced exposure to fine particulate matter improves the health outcomes of newborn children, many of which are recognized as markers for future life success such as educational attainment. Overall, we find the implementation of the CAIR reduced the proportion of premature births in affected areas, as well as the proportion of newborns with low birth weight in these areas. These findings may have longer-run impacts. For example, several studies find that premature birth is connected with lower cognitive ability and later behavioral issues. Moreover, premature births are very costly in the near term, with the average medical cost for a premature baby’s first year of life being ten times that of a healthy, full-term newborn. Moreover, we find that newborns categorized as being in “high-risk” pregnancies (i.e., those with conditions such as diabetes, hypertension, or eclampsia) experience a reduction in infant mortality.
