Researchers from the NIOSH Western States Office and the Division of Applied Research and Technology (DART) conducted a sample of personal breathing zones to evaluate exposures to respirable crystalline silica, a human lung carcinogen, during hydraulic fracturing. A report, "Occupational Exposures to Respirable Crystalline Silica During Hydraulic Fracturing," on the study was recently published in the Journal of Occupational and Environmental Hygiene and says that respirable crystalline silica is an occupational exposure hazard for oil and gas extraction workers.
The study, which claims to be the first systematic investigation of worker exposure to crystalline silica during directional drilling and hydraulic fracturing, was conducted at 11 sites in five states over a 15-month period to evaluate exposures. Michael Breintenstein, of NIOSH DART, says that work in this industry does require employees to be in areas where respirable silica levels may exceed defined exposure limits and that in the study, it was found that some personal breathing zone exposures exceeded 10 times the recommended exposure limits.