In April 2012, Eric Esswein, an industrial hygienist from the National Institute for Occupational Safety and Health, made a statement at a conference sponsored by the Institute of Medicine that was guaranteed to attract the attention of plaintiffs’ attorneys looking for a new source for silicosis lawsuits. Esswein linked the sand used in hydraulic fracturing to silicosis. His statement came after conducting air sampling in 2010 and 2011 around workers and well heads at 11 wells in five states: Colorado, Arkansas, Pennsylvania, Texas and North Dakota. He found that 4 of 5 samples exceeded the recommended exposure limits (REL) for airborne silica, with 1/3 of the samples showing levels greater than 10 times the RELs.
Esswein acknowledged that even though the companies had a good emphasis on safety regarding the handling of the toxic chemicals used in fracking operations, he felt that there was insufficient attention to health and exposure issues. Hydraulic fracturing is a process that creates fractures in low permeability reservoirs to increase the recovery of oil and gas. In a hydraulic fracturing operation, large volumes of water, sand (or other proppants) and chemicals are injected into the reservoir at high pressure to fracture the reservoir and increase production. Sand or proppants are blended in the fracking fluid and act to hold open the fractures created by the process, allowing oil and gas to flow out of the formation into the production casing. The chemicals and ingredients used in fracking fluid range from known carcinogens such as benzene to coffee grounds and walnut shells. In a 2011 report, the Democratic staff of the House of Representatives Committee on Energy and Commerce listed 750 chemicals and components used in hydraulic fracturing products between 2005 and 2009. Crystalline silica appeared in 207 products. In his recent statement, Esswein alleged there are even greater amounts of sand being used today in fracking operations than there was 10-15 years ago.
The data from Esswein’s survey is to be published in trade and scientific journals this year. The size of his sampling and the levels found raise questions, but do not indicate a source of acute silicosis. As a comparison, the silica levels involved in sandblasting can reach more than a thousand times the RELs if uncontrolled. The latency period for simple or chronic silicosis is around 10 years. Although the International Agency for Research on Cancer lists crystalline silica as a human carcinogen, this is a connection that has been debated by epidemiologists and other medical specialists in the industry and the courts. Mass tort litigation surrounding silicosis and related diseases is mature, and plaintiff attorneys are always looking out for new industries and defendants with deep pockets. The industrial hygiene control concepts and medical causation issues are well developed. Crystalline silica must be fractured down to a respirable size and become airborne before it can be linked to a risk for silicosis. On its face, the simple inclusion of crystalline silica in the slurry pumped into the ground does not immediately raise concerns of overexposure to airborne respirable-sized particles; however, if the process does in fact cause air monitoring levels to exceed RELs and expose workers above time weighted averages, the oil and gas service industry might find itself pulled into this mass tort world. It will be instructive to see exactly what and how Esswein measured in his study.
The questions of how the fracking process releases airborne respirable silica particles, the levels and sizes to which workers may be exposed, the protections and engineering controls available, and the time weighted averages of any exposures are still open, but this is an issue for oil and gas service and drilling companies to keep on their radar.