Within two month period starting March through May Coal Workers' Health Surveillance Program identified 30 miners with pneumoconiosis out of a total of 328 miners who were screened.
Dr. V. C. Antao and associates in the CDC's Morbidity and Mortality Weekly Report for August 25 report that there were eleven cases of advanced disease, of which nine have worked in mines for 31 years after the law came into effect.
The Federal Coal Mine Health and Safety Act mandated limits of 2 milligrams of dust per cubic meter in areas where miners work.
Though the rate of occurrence of pneumoconiosis declined after 1969, however, the cases of rapidly progressive disease began reappearing in 1996, primarily in Virginia and Kentucky.
Antao's team from the National Institute for Occupational Safety and Health reports that 31 percent of the estimated 1055 underground coal miners employed in southwestern Virginia were screened at mobile examination units. The subjects were asked to complete questionnaires regarding their health and work history, and underwent spirometry to determine lung capacity, and chest X-rays.
Nine percent of those screened had evidence of rapidly progressive pneumoconiosis. As mentioned there were 11 most advanced cases, and only two subjects had started mining before the 1969 limits took affect.
According to authors of a related editorial there should be some 5.5 cases of advanced coal workers' pneumoconiosis if dust levels had not exceeded the current limits and 11.9 cases if miners' exposure averaged double the limit.
They therefore suggest that mandated levels of dust are too high, and should be lowered to 1 milligram per cubic meter as suggested by the National Institute for Occupational Safety and Health.
The report also notes 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."
