Each year, one of every eight infants born in the United States is premature, according to the Centers for Disease Control and Prevention,. It’s a problem that has increased by 36 percent over the last 25 years, according to the March of Dimes, and it's the leading cause of death among newborns.
What if you could dramatically reduce the incidence of pre-term births with policy decisions?
A study conducted by Janet Currie and Reed Walker [PDF] (at Columbia University when they did this work) suggests you can. The study, part of the MacArthur Foundation's "How Housing Matters" initiative, looked at the effects of an E-ZPass tolling program installed on roads in New Jersey and Pennsylvania. Such technology results in less pollution because cars drive right through toll plazas rather than stopping and starting. In one location within the study area, nitrogen oxide fell by 11 percent after the implementation of E-ZPass.
Another thing that went down markedly? Premature births. After analyzing birth records, researchers estimated that among the 30,000 births to mothers living within two kilometers of a toll plaza, 255 premature births and 275 low-birth-weight births were avoided. In dollar terms, the researchers – writing in the American Economic Journal: Applied Economics – estimate the savings was between $9.8 and $13 million.
In human terms, the savings are incalculable. The health implications for a premature baby’s life going forward can be debilitating and permanent in the most severe cases: cerebral palsy, intellectual disabilities, vision problems, and hearing loss are just a few of the possible effects.
A brief from the MacArthur Foundation summarizing the research on the E-ZPass [PDF] notes that 26 percent of housing in the U.S. is plagued by street noise or other problems resulting from motor traffic. As many as 1 million infants could be affected, and reducing the mothers' exposure to air pollution from congested roads "could reduce preterm births by as many as 8,600 annually, for a cost savings of at least $444 million per year."
While some risk factors for premature birth are well-known – chronic health problems in the mother, the presence of twins or triplets, the use of alcohol, cigarettes, or other drugs – the causes of this devastating problem are not fully understood.
On the CDC information page about premature birth, air pollution is not listed as a known risk factor. Their numbers do show, however, that black women are 50 percent more likely than white women to give birth prematurely. "The reasons for the difference between black and white women remain unknown and are an area of intense research," according to the CDC.
An unrelated study, just out from the University of Minnesota, shows that minorities are disproportionately affected by air pollution. One of the researchers on that project notes that more non-whites tend to live in heavily polluted areas downtown and near freeways. The March of Dimes is funding research into the effect of air pollution on preterm birth.
While implementing E-ZPass-type tolling is one way to reduce pollution, the MacArthur Foundation brief looks at broader solutions, suggesting that policy makers should take the link between roadway pollution and infant health into account when making public transportation investments and when zoning for residential areas. "The costs of implementing 'traffic taming' measures in residential areas may be at least partially justified by their health findings," according to the brief, which also notes, "Unfortunately, housing that is affordable to low-income families is more often in the path of pollutants. Those who can afford to move away from potentially harmful or noxious environments do."
This analysis raises the question of why we continue to encourage driving, with free on-street parking, toll-free bridges, disinvestment in public transportation, and sprawl development. It's just one more example of how we are all paying the cost of auto-centric development, whether we choose to drive ourselves or not.