"Black lung" still occurring in US miners

NEW YORK, Aug 25 (Reuters) Despite laws aimed at limiting the amount of coal dust in mines, coal miners are still coming down with 'black lung' or pneumoconiosis, according to a report from the Centers for Disease Control and Prevention.

From March to May of this year, the Coal Workers' Health Surveillance Program identified 30 miners with pneumoconiosis out of a total of 328 miners who were screened. Of these, 11 had advanced disease, Dr V C Antao and associates report in the CDC's Morbidity and Mortality Weekly Report for August 25.

The Federal Coal Mine Health and Safety Act of 1969 mandated limits of 2 milligrams of dust per cubic meter in areas where miners work. Subsequently, the rate of occurrence of pneumoconiosis declined. However, clusters of rapidly progressive coal workers' pneumoconiosis began reappearing in 1996, primarily in Virginia and Kentucky.

Thirty-one per cent of the estimated 1055 underground coal miners employed in southwestern Virginia underwent screening at mobile examination units, reports Antao's team from the National Institute for Occupational Safety and Health. The subjects completed questionnaires regarding their health and work history, and underwent spirometry to determine lung capacity, and chest X-rays.

As mentioned, 30 (9 per cent) of those screened had evidence of rapidly progressive pneumoconiosis.

The 11 most advanced cases had worked in the mines for an average of 31 years, and only two subjects had started mining before the 1969 limits took affect.

The authors of a related editorial estimate that 5.5 cases of advanced coal workers' pneumoconiosis would be expected if dust levels had not exceeded the current limits. In contrast, 11.9 cases would be expected if miners' exposure averaged double the limit.

They therefore suggest that mandated levels of dust are too high, and should be lowered to the ''recommended exposure limit'' of 1 milligram per cubic meter suggested by the National Institute for Occupational Safety and Health.

The editorialists also note that the 11 cases of advanced coal workers' pneumoconiosis should be considered ''a sentinel health event and justifies a comprehensive assessment of current dust-control levels.'' REUTERS SKU PM1023