Document RpJqbnw5q5ORja9DZmDGQD6p8

Anthraco-Silicosis or Minors Asthma is an occupa tional disease resulting from breathing air containing silica dust particles in the mining and preparation of anthracite coal. In final stages of the disease, tuberculosis or other lung diseases attack the weakened lungs. There are ap proximately 150,000 anthracite miners in Pennsylvania. A thorough medical examination of 2,711 anthracite work ers by the U. S. Public Health Service in 1933 furnished the best information yet available on this disease. Three mines were selected, one each from the northern, western and southern anthracite fields. The mines chosen included all methods of mining--old, modern and semi-modern. Mine operators and United Mine Workers of America cooper ated In an effort to find tho facts. Of all the workers examined, 23 per cent were found to have anthraco-silicosis to some extent. The natural health of these men is shown by the fact that new employes shewed a lower tuberculosis rate than the average for the same group of men in the United States. But closer examination of the cases disclosed that the amount of silica dust in the air breathed determined tho degree of danger. Anthracite mining did not mean that anthraco-silicosis was inevitable. The kind of work per formed and the mining methods used also controlled the /degiot* of dongor. As disclosed by the study, air with less than 5 million par ticles of dust per cubic foot and a silica content of less than 5 per cent was not dangerous. However, as the dust con tent increased to over 300 million particles per cubic foot, as many as 89 per cent contracted anthraco-silicosis. Comparison of tho different methods of mining disclosed dearly that the dust danger was very greatly reduced by wet mining methods in drilling, loading and cleaning. Those making the survey came to the conclusion that although' better ventilation and mechanical loading would aid, the greatest possible use of wet mining would be the most important single preventative of anthraco-silicosis. J