It may have something to do with the increased man-hours at domestic coal mines that occur when energy prices rise.

Or am I mistaken?

I know that, for a while, the industry was in a slump. It had a major resurgence in the seventies, another minor slump in the eighties (I think), and a major upswing just recently.

If researchers are looking at twenty or thirty year averages from, say, 1940-1970, and comparing them to numbers from 1970-2000, there's going to be a huge discrepancy. Of course more people are going to be admitted into the hospital with the disease if more people are underground mining coal during that period of time. I don't know if the CDC numbers take into account the cyclical decrease/increase in the number of underground workers or not, I have to take a look at the report.

If the researchers are just looking at hospital admissions, they're going to have a false picture of the frequency of the disease.

Just a thought...

I'm gonna check out the report and see if I can find the answer to my question. If they did indeed factor production/employment levels into their figures, there's got to be something else going on.

(Edit: Two more theories have cropped up, after reading the article and doing a bit of digging, no pun intended. First theory - scummy companies putting workers at risk for the profit motive. Second theory - fewer smokers. Smoking coats the lungs in a gooey barrier of tar and mucuous, and it forces more expectoration, which can protect somewhat against a build-up of coal dust in the lungs. That's the best I can do at the moment. The fact that the hotspots are breaking the national trend would seem to invalidate the second theory, but they may be pockets of non-smokers, I dunno. The notion of more toxic coal is definitely plausible, I suppose they'll have to do some testing to determine whether or not that's the case. )

[edit on 5-10-2006 by WyrdeOne]