The AP headline read: “Regulators: Coal dust samples compliant with new rule.”  The accompanying story was based on a news release issued by the Mine Safety and Health Administration on January 15. News outlets throughout US coal mining regions picked up the AP story. It said this:

Federal regulators say samples collected from U.S. mines last year found the lowest levels of breathable coal dust since stepped-up efforts aimed at reducing miners’ exposure. The U.S. Mine Safety and Health Administration says nearly 99 percent of samples taken from August through December at underground and surface mines were compliant with a new federal rule.

The “new federal rule” was issued by MSHA in April 2014 to address miners’ exposure to respirable coal dust and lung disease associated with it. It becomes fully effective in August 2016. The new rule includes reducing the permissible exposure limit (PEL) for respirable coal dust from 2.0 mg/m3  to 1.5 mg/m3, requiring continuous monitoring of coal dust levels, and eliminating the practice of using an average of five dust samples to determine whether a citation will be issued for violating the PEL.

The AP story headline “Coal dust samples compliant with new rule” caught my attention. I had to read MSHA’s announcement for myself. MSHA chief Joe Main wrote:

“The [annual] average dust level in samples collected by MSHA inspectors in 2014 dropped to an average of 0.70 mg/m3.That compares to 0.83 m/m3 in 2009.”

I thought it was a little funny seeing MSHA announce these findings by reporting “average dust level” to characterize workers’ exposure to coal dust. It’s been a contentious, two decades-long fight by MSHA to get away from a requirement to rely on the average of sample results to take enforcement action.

A key provision in its new regulations is being able to determine a mine operator’s compliance with dust limits based on the results of a single full-shift sample. The trouble with the old MSHA system was that workers doing certain jobs were overexposed to coal mine dust, but the average of samples from workers doing different tasks was not over the PEL. If the average result wasn’t over the PEL, the mine operator did not receive a citation to force correction of the dusty conditions.

This reporting by MSHA of  the annual average coal dust level just seems strange. It’s like reporting the average speed limit on an interstate highway. The annual average speed may be 50 miles per hour. But what I’d like to know is how many times and the circumstances when vehicles are caught going 10, 20 or more MPH over the speed limit. MSHA telling us that in 2014 the annual average dust levels in coal mines was 0.7 mg/m3 seems meaningless.

The other thing that struck me in MSHA’s announcement was this:

For the period August 1 through December 31, 2014, “the  dust samples collected by MSHA and mine operators… show extremely high compliance with the new standards, with 99% of the 23,600 valid samples meeting compliance levels.”

The trouble is, there is no new compliance level. The current exposure limit—2.0 mg/m3—remains in place. A more protective exposure limit of 1.5 mg/m3 will not take effect until August 2016. All the “99%” tells me is that US mine operators have no trouble whatsoever complying with a PEL that’s been in place for more than 30 years.

What would have been informative is the percentage of samples with dust concentrations at or below the pending 1.5 mg/m3 exposure limit. The mining industry has been moaning and groaning that adopting this more protective level is infeasible. But as MSHA noted in its final rule, for some key mining tasks more than 50 percent of samples collected by MSHA were not only below the 1.5 mg/m3 level, but already at levels at or below 1.0 mg/m3.

For 20 years, coal mine operators been allowed to run their operations with dust levels that NIOSH concluded would cause thousands of case of lung disease.I still can’t help but think that Labor Secretary Tom Perez and MSHA chief Joe Main missed an opportunity to require an even more protective 1.0 mg/m3 PEL.