LITTLE ROCK — Sand used during hydraulic fracturing poses a health risk for workers in the oil and gas industry because the dust can affect the lung’s ability to absorb oxygen, according to an alert issued by federal officials.
Companies need to be aware of the dangers of overexposure to respirable crystalline silica, which is found in the sand used at oil and gas well sites, according to the alert issued last week by the U.S. Department of Labor’s Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health, which is part of the Centers for Disease Controland Prevention.
A study by the National Institute for Occupational Safety and Health triggered the alert after it found silica overexposure to be a health hazard to those working in hydraulic fracturing operations.
Respirable silica is a common hazard in many industries, but because largeamounts of silica sand is used during hydraulic fracturing, or fracking, the institute began researching its presence at oil and gas wells in 2010.
“Exposure to silica [is] one of the oldest known hazards,” said Eric Esswein, an industrial hygienist who worked on the research. “It’s not anything new to industry, but the results of this finding is newto this industry.”
Southwestern Energy, the largest natural gas producer in Arkansas’ Fayetteville Shale natural gas fields, tries to identify hazards for its workers and offers respirator protection and routine screening for diseases, said Christina Fowler, a spokesman for the Houston-basedproducer, in an e-mail.
Southwestern also hired a consultant to test the sand used in fracking in 2010 and 2011 and, as a result, the company implemented controls to reduce silica dust on location, including a vacuum system to catch airborne silica, she said.
Esswein said another way to reduce the silica risk is to substitute in a less hazardous material, but that is not always possible because of other chemicals used at the well site.
Crystalline silica, a common mineral from the earth’s crust, is primarily quartz and a big component of sand, clay and stone materials that are used to make products such as glass and brick, according to the alert. Respirable silicais a particle of the mineral that is small enough to enter the lungs if inhaled.
Silica sand is a health concern because people who constantly breathe the mineral have a bigger risk of developing silicosis, a disease where silica particles cause inflammation and scarring in lung tissues and ultimately reduce the organ’s ability to take in oxygen. Symptoms include shortness of breath, fatigue and labored breathing.
Silica can also cause lung cancer and has been connected to other diseases, such as tuberculosis and kidney and autoimmune disease, according to the alert.
Esswein said it takes many months or years before a person starts showing signs of silicosis, but once they do, it’s hard to get rid of.
“We are in the business of prevention. The nature of silicosis is very important,” Esswein said. “If workers come down with silicosis, or anyone does, once you have the disease and inhale enough silica, the disease progresses.”
In fracking, silica sand is used to help release natural gas and oil. To do this, sand is mixed with thousands of gallons of water and chemicals and then injected into wells to break apart rock and release natural gas and oil. Water and sand make up about 99 percent of the mixture used.
The amount of sand used during fracking varies and depends on a specific well, said Lawrence Bengal, director of the Arkansas Oil and Gas Commission. On average, about one- to two- thousand tons of sand is used per well, he said.
The institute found that workers were most exposed to silica dust when sand was moved and blended. Dust, containing up to 99 percent silica, can be released into the air by transporting, moving and refilling silica sand into and through sand movers, along transfer belts and blender hoppers, according to the alert.
During the institute’s study, air was sampled at 11 sites in five states. One of these sites was in Arkansas. Esswein would not disclose the location of the site because he did not want to single out one company.
As of February, there were about 4,000 natural gas wells in the Fayetteville Shale area, where the fracking process is used.
Bengal said the commission doesn’t have any regulations concerning sand used at well sites because it doesn’t regulate chemicals or worker safety.
Silica sand is used in fracking because it is able to reside inside a black shale formation and endure high pressure, heat and an acidic environment, said Thomas Dolley with the U.S. Geological Survey.
Arkansas is also a major producer of silica sand, Dolley said.
Of the 152 sand mining permits in Arkansas, 18 are for fracking sand, said Katherine Benenati, spokesman for Arkansas Department of Environmental Quality.
Southwestern Energy owns a facility in North Little Rock that manufactures its own silica sand for the company to use in its Arkansas operations, spokesman Fowler said.
“Our process is to dredge the sand from an existing mining pond, classify and clean the sand in a wet process, and then dry and screen the sand into the final product,” she said. “From there, we truck the sand to the well site.”
Business, Pages 21 on 06/28/2012