OCCUPATIONAL RESPIRATORY DISEASE SURVEILLANCE

Enhanced Coal Workers' Health Surveillance Program

Target: Surface Mines (2010-2011)

State Summary Report

STATISTICS FOR SURFACE MINERS WORKING IN MONTANA

Demographics Data

For this survey, there was an estimated employment of 639 in 2010. Of those 639 employed, there were 183 examined for a participation rate of 29%.

The mean age for 183 miners is 46 and ranged from 21 to 65.
The mean tenure for 13 miners is 4 and ranged from 1 to 19.

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Prevalence of Disease

Of the 183 miners examined:

3 miners ( 2%) showed signs of pneumoconiosis reported as >= 1/0 or PMF.
1 miner ( 1%) showed signs of pneumoconiosis reported as >=2/1 or PMF.
1 miner ( 1%) showed signs of PMF.
1 miner ( 1%) showed signs of advanced pneumoconiosis.

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Distribution of Radiographic Findings

For the 183 miners examined, the distribution of the miners in the profusion of small opacities categories is:

93% ( 171 miners ) showed the small opacity category of 0/0.
5% ( 9 miners ) showed the small opacity category of 0/1.
0% ( 0 miners ) showed the small opacity category of 1/0.
1% ( 1 miner ) showed the small opacity category of 1/1.
1% ( 1 miner ) showed the small opacity category of 1/2.
0% ( 0 miners ) showed the small opacity category of 2/1.
1% ( 1 miner ) showed the small opacity category of 2/2.
0% ( 0 miners ) showed the small opacity category of 2/3.
0% ( 0 miners ) showed the small opacity category of 3/2.
0% ( 0 miners ) showed the small opacity category of 3/3.
0% ( 0 miners ) showed the small opacity category of 3/+.

For the 183 miners examined, the distribution of the miners in the large opacities stages is:

99% ( 182 miners ) showed the large opacity stage of O.
0% ( 0 miners ) showed the large opacity stage of A.
1% ( 1 miner ) showed the large opacity stage of B.
0% ( 0 miners ) showed the large opacity stage of C.

For the 183 miners examined, the distribution for symbol ax is:

1% ( 1 miner ) showed coalescence of the small opacities.

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Methods used for the Demographics Data

SURVEY PARTICIPATION RATE: count of the number of miners with a valid x-ray during the survey period (NUMBER OF MINERS EXAMINED) divided by the count of the names on the most recent mine rosters submitted to NIOSH by the mine operators (ESTIMATED CURRENT EMPLOYMENT).

AGE - MEAN: summation of the calculated age at time of the x-ray divided by count of participating miners who provided their date of birth (N).

TENURE - MEAN: summation of the reported years in various underground mining occupations divided by count of participating miners with a completed work history (N).

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Methods used for the Prevalence of Disease Data

>= 1/0 or PMF: number of x-rays with a final determination (consensus based upon NIOSH procedures) of the International Labour Office (ILO) small opacity profusion category 1/0 or higher or with the presence of large opacities, divided by the number of participating miners with a valid x-ray.

>= 2/1 or PMF: number of x-rays with a final determination (consensus based upon NIOSH procedures) of the International Labour Office (ILO) small opacity profusion category 2/1 or higher or with the presence of large opacities, divided by the number of participating miners with a valid x-ray.

PMF: number of x-rays with a final determination of ILO large opacity category "A", "B", or "C" divided by the number of participating miners with a valid x-ray.

ADVANCED: number of x-rays with a final determination of ILO small opacity profusion category 2/1 or higher and presence of symbol "ax" (coalescence of small opacities) or ILO large opacity category of "A", "B", or "C" divided by the number of participating miners with a valid x-ray.

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Methods used for the Distribution of Radiographic Findings

PROFUSION OF SMALL OPACITIES, LARGE OPACITIES & SYMBOLS: count and percent of the x-rays using the final determination of the ILO small opacity, the final determination of the ILO large opacity, and symbol "ax" (coalescence of small opacities).

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