Drilling in the Marcellus Shale to release natural oil and gas, also known as hydraulic fracturing or "fracking" for short, has been controversial for its potential environmental impact. Those concerns are counterbalanced by the need for natural gas and the financial benefits to those who are selling rights to drill under their land, many of whom are farmers facing difficult financial times. Opponents of fracking have presented some concerns about potential health effects from fracking and its byproducts. Whether those health concerns are legitimate and who would be responsible for adverse health effects is of interest to the plaintiffs bar.

Whether or not fracking raises potential health hazards is the subject of much controversy. In an op-ed article in The Daily Caller titled "Fracking Doesn't Pose Health Risks," Dr. Elizabeth Whelan, president of the American Council on Science and Health, stated that "fracking doesn't pollute water or air. No documented instances of adverse health effects have been linked to fracking." However, opponents of fracking disagree.

Fracking has the potential to provide many important benefits. No one can doubt the significance of boosting the U.S. economy, giving landowners — particularly farmers — an increased value for their property and providing the country with a domestic source of natural gas and oil. Marcellus Shale natural gas is located in 104,067 square miles of Ohio, West Virginia, Pennsylvania, Maryland and New York. In an article in The Oxford Energy Forum titled "Benefits of Hydraulic Fracking," Kevin Hassett and Aparna Mathur wrote that "in 2011, the U.S. produced 8,500,983 million cubic feet of natural gas from shale gas wells. Taking an average price of $4.24 per thousand cubic feet, that's a value of about $36 billion, due to shale gas alone." Clearly, in a country dependent on foreign gas and oil, a rich source of domestic energy should not be ignored, unless the risks to health clearly outweigh the benefits.

Workers in the fracking industry have direct potential exposure to chemicals and potential hazards, including exposure to silica during the initial drilling of wells. Most workers already wear respirators to protect from such risks, and companies employ dust-suppression methods. The Occupational Safety and Health Administration has well-established exposure limits for silica, which minimizes any potential risks to workers in the fracking industry.

Fracking opponents do not limit their concerns to the risks of workers who perform the drilling. Opponents have raised concerns about the chemicals used by workers during the fracking process and risks of contamination to land and groundwater. Potential groups of plaintiffs go beyond the workers who conduct the drilling and include landowners who lease their land for drilling and who have potential exposure to the same chemicals as the workers, albeit at far lower doses. Another potential group of plaintiffs are those who live downstream from the fracking process whose water may contain some of the byproducts. The potential risks to each of these groups differ significantly in terms of dose, proximity and frequency of exposure.

If asbestos litigation taught us anything, it is that those with very low, intermittent or indirect exposure may nevertheless pursue claims against viable companies, regardless of the level of exposure to those companies' products. For example, Gregg v. V.J. Auto Parts, 943 A.2nd 216 (Pa. 2007), was a lawsuit against the defendant for two or three exposures to brakes.

In 2010, at the urging of Congress, the Environmental Protection Agency commenced a study of the potential health hazards associated with fracking. The final report of the EPA's study is slated for release in 2014. The stated purpose of the study is "to assess the potential impacts of hydraulic fracturing on drinking water resources, if any, and to identify the driving factors that may affect the severity and frequency of such impacts." The EPA has made no determinations of the extent of exposure to any of the approximately 1,000 chemicals that can be used in fracking fluid. Many of these chemicals have been previously assessed for their health risk potential, and levels of exposure that are considered to pose little risk to human health have been established by the EPA. Whether or not levels will be found in drinking water in excess of the EPA-established exposure limits is an open question.

Finding high levels of a particular chemical in water does not necessarily translate into a potential risk. The risk will depend upon the chemical, the amount actually ingested and other potential exposures to similar toxins. In addition, trace amounts of numerous chemicals can be found in water without fracking. Whether or not fracking will be a source of those chemicals at elevated levels remains to be seen. At least in one instance, the Pennsylvania Department of Environmental Protection concluded that fracking was not responsible for methane found in private wells in the northeast corner of Pennsylvania. Rather, the methane was traced back to naturally occurring deposits of the gas in the area.

Such studies suggest that there will not be a robust source of future litigation from the fracking industry. Nevertheless, wise companies involved in fracking can defend against potential claims by knowing where they are releasing byproducts and the potential levels of the chemicals they are releasing.

Sharon L. Caffrey is chair of the products liability and toxic torts division of Duane Morris' trial practice group. She concentrates her practice in the areas of mass torts, products liability, and toxic tort litigation. She has significant trial experience, including extensive experience as MDL counsel in both asbestos and PPA litigation.