A 2012 study by a Cornell graduate student Elaine Hill that found a 25% increase in low-birth weight babies within 1.5 miles (7920 feet) of a gas fracking sites in Pennsylvania got a boost from a follow-up study previewed over this last weekend at a conference in Philadelphia.
Janet Currie of Princeton University, Katherine Meckel of Columbia University, and John Deutch and Michael Greenstone of the Massachusetts Institute of Technology also looked at Pennsylvania birth records and found the risk of low-weight births increased by 50% within 2. 5 kilometers (8125 feet) of a fracking site. That's over 7 times the distance of the recent 1500 foot buffer zone between homes and drilling pads passed by the City of Dallas last month.
This rate was constant for both households with their own water wells and municipal water system users, seemingly ruling out water contamination as a cause. Air, noise and light pollution are now the suspected culprits.
This second study was specifically designed to address critics of Hill's previous work:
"….they built on the work of Elaine Hill, a PhD student at Cornell University who sparked controversy in 2012 with a study showing that infants born near fracked gas wells had more health problems than infants born near sites that had merely been permitted for fracking. One criticism of Hill's study was that fracking activity might change the demography of an area, attracting more mothers who are likely to give birth to infants with health problem.
The new research addresses such concerns by following a constant group of mothers who had children both before and after the onset of fracking, and by controlling for geographical differences in mothers' initial health characteristics. It seeks to achieve the rigor of a controlled experiment by focusing on mothers who, due to their locations and the dates of their pregnancies, were effectively selected at random to be exposed to fracking.
The study is expected to be accepted for publication sometime this Spring after being peer-reviewed.