According to reporter Alex Wayne of Business Week, fracking sand dust from the hydraulic fracturing to extract natural gas is one of the most dangerous threats to workers on wellpads reports a government safety researcher. Eric Esswein, an industrial hygienist at the National Institute for Occupational Safety and Health (NIOSH) says that over 75% of air samples show high dust levels. The particles in sand dust created during the fracking process can lodge in the lungs and cause potentially fatal silicosis, he said at a conference sponsored by the Institute of Medicine on April 30^th.

Esswein, whose agency is part of the Centers for Disease Control and Prevention, said his team spent about 225 hours visiting 11 well sites in Colorado, Arkansas, Pennsylvania, Texas and North Dakota in 2010 and 2011, with the consent of drilling companies, to examine safety practices. He took air samples from workers and near wellheads, to test for contaminants, and found elevated levels of silica most places. In about one-third of the samples, he said, silica levels were more than 10 times recommendations.

Workers were careful while handling dangerous chemicals and generally knew what to do in the event of emergencies, he said. “There’s a big focus on safety” at well sites, Esswein said. “There isn’t as much emphasis on health. We call it big ‘S’ and little ‘H.’” Esswein said he didn’t know whether the sand dust may be harmful to local residents because his team didn’t take measurements at the edges of well sites. He plans to publish data from his survey in trade and scientific journals this year.

However, according to Steve Everley of Energy In Depth, “When it comes to claims that hydraulic fracturing is causing people to get sick more frequently or more severely, the data simply do not support that conclusion.” His group advocates for drilling-friendly policies on behalf of gas companies including Chesapeake Energy. Workers at gas wells are generally safer than in other businesses, Everley said, pointing to U.S. Bureau of Labor Statistics data that show the incidence of non-fatal injuries in the oil and gas extraction industry is less than half the national average.