by Elizabeth Grossman
In response to results of the recently released National Institute for Occupational Safety and Health (NIOSH) field studies that found workers at hydraulic fracturing operations exposed to high levels of respirable crystalline silica, the Occupational Safety and Health Administration (OSHA) and NIOSH have issued a Hazard Alert. The alert outlines the health hazards associated with hydraulic fracturing and focuses specifically on exposures to airborne silica, saying that “employers must ensure that workers are properly protected from overexposure to silica.” It also describes a combination of measures that can be used to protect workers, including engineering controls, protective equipment, and product substitution. While it says that engineering controls and work practices will provide the best protection, its recommendations for preventing silica exposure also include using substances other than silica sands.
“Hazardous exposures to silica can and must be prevented. It is important for employers and workers to understand the hazards associated with silica exposure in hydraulic fracturing operations and how to protect workers,” said David Michaels, assistant secretary of labor for occupational safety and health in a press statement. “OSHA and NIOSH are committed to continuing to work with the industry and workers to find effective solutions to address these hazards.”
As reported previously by The Pump Handle, NIOSH’s recent investigation of silica exposure at fracking operations recorded many air samples with silica levels “above defined occupational exposure limits” for workers both directly and indirectly exposed to operations producing this dust. Given the serious health hazards posed by breathing silica dust, preventing these exposures is a matter of urgency.
Stirring up sand
As OSHA explains, hydraulic fracturing typically involves large quantities of silica sand. Depending on its size and complexity, a single fracking operation may use anywhere between a few tons to more than two million pounds of sand that’s usually nearly 100% silica. The sand, which is specially processed to meet American Petroleum Institute specifications and used to prop open fissures through which gas can be extracted, is injected into drilling holes along with hydraulic fracturing fluids. Sand arrives from mining and processing facilities at well sites by truck, and is then loaded onto sand movers, then transferred by conveyer belt and blended with the fracking fluids. “Transporting, moving, and refilling silica sand into and through sand movers, along transfer belts, and into blender hoppers can release dusts containing silica into the air. Workers can be exposed if they breathe the dust into their lungs,” explains OSHA.
Breathing silica can cause silicosis, in which, as OSHA describes, “lung tissue around trapped silica particles reacts, causing inflammation and scarring and reducing the lungs’ ability to take in oxygen.” Workers who breathe silica daily are at risk of developing silicosis. Silica can also cause lung cancer and, says OSHA, has been linked to other diseases, including tuberculosis, chronic obstructive pulmonary disease, and to kidney disease and autoimmune disorders.
Following up on NIOSH’s observation at the 11 fracking operations it examined, the alert describes how silica dust can be released from hatches on sand movers while the machines are running (what’s called “hot loading”), through open filling-ports on the sides of sand movers, by sand transfer belts and related machinery, and by on-site vehicle traffic. NIOSH found that in addition to workers more directly exposed, workers “upwind and not in the immediate area of sand movers” also had silica exposures that exceeded recommended levels, as did those in “enclosed but non-filtered” vehicle cabs.
“We are proud of the development of an industry focus group in cooperation with those agencies which will further explore this issue, share best practices and continue to build upon the many engineering controls currently in place and those under development over the last several years,” said Kenny Jordan, executive director of the Association of Energy Service Companies, in a press statement. “The safety and health of our workforce is a top priority, and the industry strives to follow and improve best practices for safe operations and works closely with OSHA and NIOSH to help ensure a strong culture of safety. We look forward to sharing improvements not only within our industry, but with others as well.”
Getting the word out
The hazard alert itself does not detail an outreach plan, but OSHA responded to my inquiry, explaining that its distribution of the alert, began this week and will be ongoing. The alert, said OSHA public affairs officer Egan Reich, will go out through networks of industry groups representing hundreds of companies in the oil and gas industry and through labor organizations representing workers in these industries. The alert will also be distributed through OSHA’s “QuickTakes” newsletter that has 80,000 subscribers and through OSHA and NIOSH field personnel, including OSHA’s compliance assistance specialists in “targeted regions.” In addition, the alert will go to OSHA “consultation” and State Plan offices in targeted states, and to worker and community organizations. Reich described this as a broad outline of the distribution strategy, suggesting that more specific numbers and details would be forthcoming.
What may be a challenge is reaching all employers and workers at fracking sites. In an interview earlier this month, National Institute of Environmental Health Sciences senior medical advisor Dr. Aubrey Miller explained that one of the traditional avenues for such outreach is through labor unions. But, he noted, many fracking operations “may not have a lot of organized labor.” Another challenge in reaching all employers and workers at these sites is the fact that many involve multiple contractors and subcontractors, which run the gamut in size from large multinationals to small local businesses.
“The AFL-CIO strongly supports this hazard alert that provides important information to employers and workers involved in hydraulic fracturing operations regarding the serious health threat from silica exposures. It is critical that OSHA and NIOSH disseminate this information, so that immediate action can be taken to protect workers from silicosis and other silica-related diseases,” said AFL-CIO Health and Safety Director Margaret Seminario, responding to OSHA’s announcement.
In May, prompted by NIOSH’s silica exposure findings, the AFL-CIO, United Mine Workers of America, and United Steelworkers wrote to OSHA, NIOSH and to the Mine Safety and Health Administration (MSHA) asking that OSHA and NIOSH issue a joint hazard alert. The unions also requested that NIOSH expand its field work in fracking to include medical surveillance; that OSHA develop a National Emphasis Program specifically for fracking work; and that MSHA evaluate mines producing fracking sands and assess worker exposure at these mines. In the just-issued alert, OSHA recommends, as part of its National Emphasis Program on Silica, that employers “medically monitor all workers who may be exposed to silica dust levels at or above one-half the PEL [permissible exposure limit],” and makes recommendation for specific medical tests.
MSHA has not yet issued a comparable alert, although its January 2012 North Central District newsletter that goes out in the upper Midwest, including Wisconsin, where much of the current frack sand mining activity occurs, did include a special section on the hazards of “respirable quartz dust at frac sand mines.”
Also requested in the union’s letter was that OSHA “immediately initiate rulemaking on a new silica standard and issue a proposed rule that includes and training” along with “a protective permissible exposure limit.” A revised OSHA silica exposure standard sent to the Office of Management and Budget last year remains under review.
Elizabeth Grossman is the author of Chasing Molecules: Poisonous Products, Human Health, and the Promise of Green Chemistry, High Tech Trash: Digital Devices, Hidden Toxics, and Human Health, and other books. Her work has appeared in a variety of publications including Scientific American, Salon, The Washington Post, The Nation, Mother Jones, Grist, and the Huffington Post. Chasing Molecules was chosen by Booklist as one of the Top 10 Science & Technology Books of 2009 and won a 2010 Gold Nautilus Award for investigative journalism.
As my June 4 post on The Pump Handle reported, NIOSH's field investigation of silica exposures at 11 hydraulic fracturing sites found exposure levels 10, 25 and 100 times recommended exposure limits. Here are the details:
– 47% showed silica exposures greater than the calculated OSHA PEL
-- 79% showed silica exposures greater than the NIOSH REL of 0.05 milligrams per cubic meter (mg/m3)
-- 9% of all samples showed silica exposures 10 or more times the PEL, with one sample more than 25 times the PEL.
– 31% of all samples showed silica exposures 10 or more times the REL, with one sample more than 100 times the REL.
My interest in this topic is dual: I am writing a book about TB sanatoria in Minnesota, and I live in Scott County, which will soon have a sand mining operation. I have read recent articles about the hazards of silica exposures. Most trace the relationship from silicosis to tuberculosis, but a book that was written in 1947 notes the reverse, too. People who test positive via a Mantoux test have a greater chance of developing active tuberculosis through exposure to silica. They may think their coughing is due to the dust, when in reality they could be infecting fellow workers with tuberculosis. Silica mining is an occupation that could benefit from TB screening of employees. I haven't found anything to indicate that it is an accepted practice.