Respiratory status of surface coal miners.
Proceedings of the Coal Mine Dust Conference, Morgantown, West Virginia, October 8-10, 1984. Peng, SS, ed., Morgantown, WV: West Virginia University, 1984 Oct; :168-174
Although both epidemiological and environmental data have inherent problems which make it difficult to assess the risk or prevalence of pneumoconiosis, same conclusions can be made: 1. Bituminous strip miners with previous underground experience have an elevated prevalence of pneumoconiosis similar to workers with comparable underground coal mine tenure. 2. In some mines, highwall drillers have elevated silica exposures and an elevated prevalence of category 1 or higher pneumoconiosis (likely silicosis). 3. Anthracite strip miners had an increased prevalence of category 2 in the 1972-73 study, but this may be explained by experience in highwall drilling or elevated dust exposures The numbers of workers studied were too small to allow firm conclusions Further study is needed. 4. Cleaning plant operators had an average coal mine dust exposure which exceeded 2 mg/m3 in approximately 3% of the preparation plants, and exceeded 4 mg/m3 in 0.3% of the plants. However, an increased prevalence of category 2 or higher hasn't been found in preparation plant workers at underground mines in NIOSH's National Coal Study. 5. The results of the 1972-1973 strip miner study didn't indicate an increased prevalence of category 2 or higher in bituminous strip coal miners. However, the average exposures from 1972-1979 were low in the study mines and the sample may have underestimated the prevalence of CWP for mines where exposures are elevated. 5. Results of the analysis of MSHA's data showed that for 1/3 of the surface coal mine job categories the average respirable coal mine dust level was greater than 2 mg/m3 in 3-6% of the mines. Thus, based on the British dose-response curve, workers with 20 years or more tenure would have an increased risk of category 2 or higher pneumoconiosis. 6. Because medical results on the prevalence of silicosis is undocumented for workers in jobs with exposures high in free silica, except for highwall drillers, it is difficult to estimate the prevalence of silicosis in these workers. It is strongly recommended that periodic examinations be offered to surface coal workers with previous underground coal mine experience and to workers with experience as highwall drillers. The results of epidemiological studies and environmental data suggest that these groups have an elevated risk of either category 2 or higher CWP or silicosis. In regard to other strip miners and preparation plant workers, epidemiological and environmental results are either insufficient, unavailable, or conflicting. The results from one or the other, however, source suggest a potential for an increased risk of category 2 or higher pneumoconiosis. It is suggested that these workers should receive periodic examinations until further evidence suggests surveillance isn't necessary. Because the prevalence and risk of pneumoconiosis is difficult to estimate in surface coal miners, NIOSH is preparing to conduct additional studies. In 1984 NIOSH will begin examinations of strip miners and preparation plant workers in the Pennsylvania anthracite coal region. This investigation will be expanded to highwall drillers in West Virginia and Pennsylvania bituminous mines. The examination will consist of a PA chest radiograph, a spirometry test, and questionnaire on occupational history, smoking habit, and respiratory symptoms.
Respiratory-system-disorders; Morbidity; Incidence; Respiratory-functions; Diagnostic-techniques; Diagnosis; Silicosis; Radiography; Time-dose-relationship; Hazards; Coal-dust
Proceedings of the Coal Mine Dust Conference, Morgantown, West Virginia, October 8-10, 1984