We have been talking about the potential for a new epidemic of silicosis brought about by exposure to silica dust at drilling sites using hydraulic fracturing, or “fracking”, as a technique to increase the production in the wells. This is particularly important in Pennsylvania where the Marcellus Shale deposits have created considerable drilling. It is important to note that the injury to lung tissue by the inhalation of silica dust, and the subsequent scarring which results, is not the only disease associated with silica exposure.
The following are the other conditions frequently associated with significant silica dust exposure. They include: lung cancer, COPD, tuberculosis, end stage kidney disease, and connective tissue diseases, most commonly rheumatoid arthritis and scleroderma.
The workers at greatest risk are the ones who demonstrate x-ray evidence of scarring in the lungs due to silica exposure. However, studies have shown that there is an increased risk to workers based on the amount of silica exposure even if x-rays show no significant scarring. The adverse effects of silica exposure typically occur 20 years or more after the initial exposure. Lung cancer, COPD and end stage kidney disease also take a long period to develop. Tuberculosis and connective tissue disease can occur much sooner after the initial exposures.
The Occupational Safety and Health Administration (OSHA) has proposed new guidelines for silica exposure levels at the drilling sites. These new guidelines are projected to reduce the incidence and complication rate of silicosis, but the potential for disease will not be zero.