Occupational Respiratory Disease Surveillance

County Summary Report

STATISTICS FOR MINERS WORKING IN BELL COUNTY, KENTUCKY

Survey Sites

X-rays were taken from 11/06/2006 through 11/19/2006 in HARLAN AND LESLIE COUNTIES, KENTUCKY.

X-rays were taken from 08/28/2007 through 08/31/2007 in MINE RESCUE CONTEST, NASHVILLE, TENNESSEE.

X-rays were taken from 04/06/2009 through 04/07/2009 in BELL COUNTY, KENTUCKY.

Demographics Data for the Survey Site

For the survey, there was an estimated employment of 191 in 2009. Of those 191 employed, there were 54 examined for a participation rate of 28%.

• The mean tenure for 29 miners is 11 and ranged from 0 to 36.
• The mean age for 54 miners is 47 and ranged from 21 to 63.
• The mean tenure at the face for 15 miners is 20 and ranged from 2 to 36.

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Demographics Data for the Five Years Prior to the Survey

For the period of 2005 through 2009, there was an estimated employment of 239. Of those 239 employed, there were 99 examined for a participation rate of 41%.

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Prevalence of Disease

Of the 54 miners examined:

• 6% ( 3 miners ) showed signs of pneumoconiosis.
• 0% ( 0 miners ) showed signs of PMF.
• 2% ( 1 miner ) showed signs of advanced pneumoconiosis.

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Observed and Expected Prevalence of Disease for Workers with 15 or more Tenure Years

For the counties included in this report, the average dust level is 0.901 mg/m3. Of the 54 miners examined, 10 had 15 or more tenure years:

• 10% ( 1 miner ) showed signs of pneumoconiosis while 10% ( 1 miner ) would be expected.
• 0% ( 0 miners ) showed signs of PMF while 10% ( 1 miner ) would be expected.
• 0% ( 0 miners ) showed signs of advanced pneumoconiosis while 10% ( 1 miner ) would be expected.

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Distribution of Radiographic Findings

For the 54 miners examined, the distribution of the miners in the profusion of small opacities categories is:

• 91% ( 49 miners ) are in the 0/0 category.
• 4% ( 2 miners ) are in the 0/1 category.
• 4% ( 2 miners ) are in the 1/0 category.
• 0% ( 0 miners ) are in the 1/1 category.
• 0% ( 0 miners ) are in the 1/2 category.
• 0% ( 0 miners ) are in the 2/1 category.
• 2% ( 1 miner ) are in the 2/2 category.
• 0% ( 0 miners ) are in the 2/3 category.
• 0% ( 0 miners ) are in the 3/2 category.
• 0% ( 0 miners ) are in the 3/3 category.
• 0% ( 0 miners ) are in the 3/+ category.

For the 54 miners examined, the distribution of the miners in the large opacities stages is:

• 100% ( 54 miners ) are in stage O.
• 0% ( 0 miners ) are in stage A.
• 0% ( 0 miners ) are in stage B.
• 0% ( 0 miners ) are in stage C.

For the 54 miners examined, the distribution for symbol ax is:

• 2% ( 1 miner ).

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Prevalence of Clinical Findings

For the 54 miners examined, 54 responded to the clinical findings questionnaire.

• 30% ( 16 miners ) have a chronic cough.
• 30% ( 16 miners ) bring up phlegm from their chest.
• 35% ( 19 miners ) have chest sounds of wheezing.
• 30% ( 16 miners ) have had an attack of wheezing.
• 17% ( 9 miners ) have experienced dyspnea on the level.
• 39% ( 21 miners ) have experienced dyspnea on a hill.
• 43% ( 23 miners ) have chest tightness.
• 4% ( 2 miners ) have chronic bronchitis.
• 6% ( 3 miners ) have emphysema.
• 15% ( 8 miners ) have had pneumonia.
• 11% ( 6 miners ) have asthma.
• 0% ( 0 miners ) have tuberculosis.

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Smoking Status

For the 54 miners examined, 54 responded to the cigarette smoking history question on the clinical findings questionnaire.

• 48% ( 26 miners ) never smoked.
• 31% ( 17 miners ) are former smokers.
• 20% ( 11 miners ) are current smokers.

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Spirometry Results

For the 54 miners examined, 52 also had a spirometry test.

• 6% ( 3 miners ) showed obstructive respiratory impairment.
• 8% ( 4 miners ) showed restrictive respiratory impairment.
• 4% ( 2 miners ) showed mixed respiratory impairment.

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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).

5-YEAR PARTICIPATION RATE: count of the number miners with a valid x-ray during the 5-year period preceding the date of the end of the survey (5-YEAR MINERS EXAMINED) divided by the count of the names on the mine rosters that accompanied the mine plans that were submitted to NIOSH by the miner operators during the 5-year period preceding the date of the end of the survey (ESTIMATED 5-YEAR EMPLOYMENT).

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

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 AT THE FACE - MEAN: summation of the reported years of working at the face divided by count of participating miners who reported working at the face (N).

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Methods used for the Prevalence of Disease Data

PNEUMOCONIOSIS: 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.

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.

EXPECTED PNEUMOCONIOSIS, PMF & ADVANCED: count and percent of expected cases of pneumoconiosis, PMF, and advanced disease for a given mean respirable dust level (concentration) and for the specific type of coal in the region, calculated according to Attfield MD, Morring K. Am Ind Hyg Assoc J 1992; 53:486-492.

AVERAGE DUST LEVEL: mean of the respirable dust concentrations for occupational samples collected by MSHA coal mine inspectors from 1975-2008.

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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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Methods used for the Prevalence of the Clinical Findings

SELF-REPORTED: count and percent of self-reported symptoms and/or medical conditions based on the participating miners who completed the health questionnaire survey.

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Methods used for the Smoking Status Data

NEVER SMOKER, FORMER SMOKER, & CURRENT SMOKER: count and percent of participating miners who completed the health questionnaire survey miners reporting each smoking history.

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Methods used for the Spirometry Results

OBSTRUCTIVE, RESTRICTIVE, & MIXED: number and percent of miners who participated in the spirometry testing and whose results showed one of the following categories of respiratory impairment using forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) ratio:

• OBSTRUCTIVE - FEV1/FVC < lower limit of normal (LLN) and FVC >= LLN
• RESTRICTIVE - FEV1/FVC > LLN and FVC < LLN
• MIXED - FEV1/FVC < LLN and FVC < LLN

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