Howard Berkes:

The government is looking at only working miners, and is actually offering free lung X-rays to working miners, and then they count the occurrence of disease as they do those X-rays.

The law limits them to only testing working miners. And the testing is voluntary. So — and the participation rate is really low. It's only 35 percent nationwide and only 17 percent in the coal fields of Eastern Kentucky.

So that's one subset of a larger group of people. What the clinics are seeing are miners who have been laid off or are retired. And there are tens of thousands more of those in the last eight years because of the downturn in mining. And those miners are going in to get tested because they're not working anymore. They're not getting paid.

And if they have disease, they can apply for black lung benefits. And so that's the difference, is, the government is not looking at the great number of retired and laid-off miners, and that's what we're seeing in the occurrence of disease now.