Labor Secretary Hilda Solis and MSHA asst. secretary Joe Main are proposing new rules to protect U.S. coal mine workers from developing illnesses related to exposure to respirable coal mine dust. The most commonly known adverse health effect is black lung disease, but exposure is also associated with excess risk of chronic obstructive pulmonary disease, progressive massive fibrosis, chronic bronchitis, and emphysema. The proposal, scheduled to be published in the Federal Register on Oct 19,* takes a comprehensive approach to the problem. I've not had a chance to read carefully the entire lengthy document, but I see provisions to reduce the permissible exposure limit for respirable coal dust from 2.0 mg/m3 to 1.0 mg/m3 (phased-in over 2 years), change the way miners' exposure to coal dust is measured from an average over five shifts to a single, full-shift sample (consistent with standard industrial hygiene practice) and monitor of coal dust levels based on typical production levels in the mine. During the Clinton and the GW Bush Administration, MSHA proposed rules addressing these same problems, but they were never issued as a final rules. I'm hopeful this third time will be the charm.
In August 2010, the National Institute for Occupational Safety and Health (NIOSH) requested public comment on a compilation of the best available scientific information on adverse health effects from exposure to respirable coal dust. The document is a follow-up to NIOSH's 300+ page Criteria Document published in September 1995 which recommended that MSHA adopt an exposure limit of 1 mg/m3 for a 10-hour shift. In the draft NIOSH update, the agency reaffirms its conclusions from 15 years earlier:
**Exposure to coal mine dust causes various pulmonary diseases, including coal workers' pneumoconiosis and chronic obstructive pulmonary disease (COPD).
**These lung diseases can bring about impairment, disability and premature death.
See the faces and hear the voices of U.S. miners who have severe respiratory diseases because of their work in these video clips produced by the Louisville Courier-Journal.
*Note: the document is available on-line today at the Federal Register "public inspection desk" site.
Hi Celeste --
You might also want to point out to your readers that
under current procedures, MSHA inspectors are required to average respirable dust samples taken on the same shift for workers with 5 different occupations who may be exposed to 5 widely different dust levels. Doing this dilutes the exposure measurements for the most highly exposed occupations. The proposed rule would eliminate this misleading way of sampling.
John is indeed correct. If this MSHA rule is adopted, it will end a practice in place since 1971 that requires the averaging a exposure samples over 5 shifts or 5 occupations. in 1994 MSHA and NIOSH attempted to change this practice (59 Fed Reg 8357, 2/18/1994) but the National Mining Association (represented by Patton Boggs) and the Alabama Coal Association challenged the policy change. In 1999, MSHA proposed changing it in comprehensive rule to address miners' exposure to coal dust, but that final rule was not published before the end of the Clinton Administration because of opposition to the rule from both the UMWA and the coal industry . In 2003, MSHA tried again to change the practice of averaging samples in another comprehensive rule, but that rule also faced strong opposition, especially because of a provision that would have allowed substantially HIGHER exposure to coal dust if miners were wearing powered air purifying respirators. Hopefully, after 40 years of this policy-practice of averaging coal dust exposure sampling results----which fails to protect the most heavily exposed coal miners---this MSHA rulemaking will succeed.
John--great to hear from you!