Occupational Respiratory Disease Surveillance

State Summary Report

STATISTICS FOR MINERS WORKING IN NEW MEXICO

Survey Sites

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

X-rays were taken from 11/03/2007 through 11/03/2007 in SAN JUAN COUNTY, NEW MEXICO.

Demographics Data for the Survey Site

For the survey, there was an estimated employment of 331 in 2007. Of those 331 employed, there were 23 examined for a participation rate of 7%.

• The mean tenure for 21 miners is 11 and ranged from 1 to 29.
• The mean age for 23 miners is 41 and ranged from 23 to 55.
• The mean tenure at the face for 20 miners is 8 and ranged from 1 to 25.

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Demographics Data for the Five Years Prior to the Survey

For the period of 2003 through 2007, there was an estimated employment of 331. Of those 331 employed, there were 148 examined for a participation rate of 45%.

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Prevalence of Disease

Of the 23 miners examined:

• 0% ( 0 miners ) showed signs of pneumoconiosis.
• 0% ( 0 miners ) showed signs of PMF.
• 0% ( 0 miners ) 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 0.612 mg/m3. Of the 23 miners examined, 7 had 15 or more tenure years:

• 0% ( 0 miners ) showed signs of pneumoconiosis while 14% ( 1 miner ) would be expected.
• 0% ( 0 miners ) showed signs of PMF while 14% ( 1 miner ) would be expected.
• 0% ( 0 miners ) showed signs of advanced pneumoconiosis while 14% ( 1 miner ) would be expected.

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Distribution of Radiographic Findings

For the 23 miners examined, the distribution of the miners in the profusion of small opacities categories is:

• 96% ( 22 miners ) are in the 0/0 category.
• 4% ( 1 miners ) are in the 0/1 category.
• 0% ( 0 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.
• 0% ( 0 miners ) 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 23 miners examined, the distribution of the miners in the large opacities stages is:

• 100% ( 23 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 23 miners examined, the distribution for symbol ax is:

• 0% ( 0 miners ).

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Prevalence of Clinical Findings

For the 23 miners examined, 23 responded to the clinical findings questionnaire.

• 17% ( 4 miners ) have a chronic cough.
• 13% ( 3 miners ) bring up phlegm from their chest.
• 4% ( 1 miner ) have chest sounds of wheezing.
• 13% ( 3 miners ) have had an attack of wheezing.
• 9% ( 2 miners ) have experienced dyspnea on the level.
• 13% ( 3 miners ) have experienced dyspnea on a hill.
• 13% ( 3 miners ) have chest tightness.
• 0% ( 0 miners ) have chronic bronchitis.
• 0% ( 0 miners ) have emphysema.
• 22% ( 5 miners ) have had pneumonia.
• 17% ( 4 miners ) have asthma.
• 0% ( 0 miners ) have tuberculosis.

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Smoking Status

For the 23 miners examined, 23 responded to the cigarette smoking history question on the clinical findings questionnaire.

• 57% ( 13 miners ) never smoked.
• 35% ( 8 miners ) are former smokers.
• 9% ( 2 miners ) are current smokers.

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Spirometry Results

For the 23 miners examined, 23 also had a spirometry test.

• 4% ( 1 miner ) showed obstructive respiratory impairment.
• 4% ( 1 miner ) showed restrictive respiratory impairment.
• 4% ( 1 miner ) 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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