PRESTONSBURG, Ky. -- Donald Marcum knew he was at least a passive participant in something that was against the rules, maybe even criminal. Every couple of months, his bosses had to submit to the Mine Safety and Health Administration five samples showing they were keeping dust levels under control. When he ran a continuous mining machine, which chews through coal and rock and generates clouds of dust, he was supposed to wear a pump to collect dust for eight hours.
That almost never happened. Most of the time, said Marcum, 51, who spent nearly 25 years in the mines of eastern Kentucky and suffers from the most severe form of black lung, the foreman or someone else would take the pump and hang it in cleaner air near the mine's entrance.
"We just done what we was told because we needed to feed our families and really didn't look at what it might be doing to our health," he said.
In recent interviews, retired miners in West Virginia, Kentucky and Virginia -- some of whom had worked as recently as 2008 -- described similar tricks. Dust pumps ended up in lunchboxes or mine offices. Mine officials stalled regulators who had shown up for a surprise inspection and radioed to the men underground, who fixed the ventilation and cleaned up the work site.
"I don't know if any [manipulation of dust samples] is going on today," said Bruce Watzman, the National Mining Association's senior vice president for regulatory affairs. "I hope not. We encourage our members to fulfill their obligations under the law."
More than 40 years ago, Congress promised that the government would force mining companies to control levels of the dust that causes black lung. Instead, rampant cheating and exploitation of legal loopholes have become part of mining culture, an investigation by the Center for Public Integrity and NPR has found.
After decades of decline, black lung is back, with more cases of the fastest-progressing form of the disease robbing younger miners of their breath. As researchers struggle to explain this resurgence, there is widespread agreement that the samples used by regulators to assess dust levels in a mine bear little resemblance to the conditions miners typically face.
Cheating aside, the system for monitoring dust is almost designed not to detect problems. Nor has MSHA always been swift to act when violations do surface.
From 2000 to 2011, MSHA received more than 53,000 valid samples -- both from companies and its own inspectors -- that showed a miner had been exposed to more dust than was allowed at an underground mine, yet the agency issued slightly fewer than 2,400 violations, a Center analysis of MSHA data showed.
This may be attributable, in part, to the way the rules are written. When companies submit five dust samples to MSHA, some samples are allowed to be above the limit. Only the average of these five has to be below; this allows companies to negate high samples taken from miners enshrouded in dust. What's more, the sampling pump runs for only eight hours, even if the miner works 10 or 12.
While an inspector is sampling, a company is allowed to mine as little as half the amount of coal it normally does. Companies make sure dust controls are working, and dust levels typically bear little resemblance to the usual conditions, several miners said.
Even when a company gets caught with samples that are too high, all it has to do to make a citation go away is take five of its own samples that indicate compliance. "The analogy I use is, if I pull you over for speeding, going 80 in a 50," Charleston lawyer Tim Bailey said, "and I tell you ... here's a journal, and I want you to record your speed on this same piece of road for the next five days. And, if at the end of those five days, your speed is below the speed limit, then I am going to tear your ticket up."
Sometimes MSHA has allowed dust citations to go uncorrected for weeks or even months, potentially leaving miners overexposed, a Center analysis of agency data shows. MSHA sets a date by which a violation must be fixed, but, from 2000 to 2011, the agency granted extensions for 57 percent of the violations.
Long extensions have been particularly common in southern West Virginia, one of the key "hot spots" of disease resurgence identified by the National Institute for Occupational Safety and Health, or NIOSH. In this area, which accounted for about 30 percent of the nation's dust sampling violations, MSHA gave companies an extension about two-thirds of the time and allowed, on average, about 58 extra days to prove compliance.
Asked about these numbers, the agency said in a statement, "The majority of these extensions ... are for good reasons such as getting approved dust controls implemented or allowing the operator time to collect additional samples to submit to MSHA."