Today, the health commissioner of the state of New York, Howard Zucker, announced that he has completed a study into the health impacts of hydraulic fracturing for the recovery of natural gas. Although there are few demonstrated health risks, Zucker noted that there are a great many uncertainties about the process, and these make it impossible to design intelligent regulations that minimize potential risks. As a result, the state will ban the practice indefinitely.

Zucker's review describes a large number of possible problems that could affect the health of residents of the state. These include air pollution, both from the equipment and the chemicals used in the fracking, as well as leakage from the wells themselves. Concerns regarding water focus on the chemicals in the fracking fluid, which can both spread underground or contaminate surface waters through spills or incomplete processing. Finally, fracking has clearly resulted in elevated earthquake risks in some areas, although the quakes remained small.

Right now, most of these risks are hypothetical; Zucker's report cites a large number of long-term, fracking-focused health studies that are in progress but aren't expected to yield results for several years. The studies that have been completed "raise substantial questions about whether the risks of HVHF [High Volume Hydraulic Fracturing] activities are sufficiently understood so that they can be adequately managed." In other words, although it might be possible to regulate fracking in a way that limits health risks, we don't know enough about the health risks themselves to design regulations.

Given the uncertainties, Zucker suggests putting the practice on hold: "While a guarantee of absolute safety is not possible, an assessment of the risk to public health must be supported by adequate scientific information to determine with confidence that the overall risk is sufficiently low to justify proceeding with HVHF in New York. "

This is a significant step for the state. The Marcellus Shale, which has fed the fracking boom in neighboring Pennsylvania, extends deep into New York as well. Many of the areas it underlies are rural and poor, meaning any additional economic activity could have an outsized impact. But some of those same areas house the water supplies that serve the state's major cities, which has caused fracking to become a contentious issue for the state's governor.

The decision technically leaves the door open to fracking at some point in the future, once the health issues are better quantified and we've gained more experience with avoiding contamination. But, given that Governor Cuomo has faced widespread opposition to the practice, this will likely be it for his time in office. And he won't lose many votes in New York by allowing Pennsylvania residents to be the test subjects.