This study is designed to construct quantitative estimates of exposure to respirable dust in US underground coal mines and to use this information in an occupational epidemiologic analysis of respiratory morbidity in coal miners. The data for the study will come from two sources. The exposure data will be obtained from the Mine Safety and Health Administration (MSHA) compliance program. This data source includes over six million personal respirable dust samples collected from all underground coal mines in the US between 1970 and 1986. From this data exposure estimates will be made for each cell in a mine/occupation/year matrix. The health data will come from Rounds One, Two and Four of the national Coal Study (NCS) administered by the National Institute for Occupational Safety and Health (NIOSH). The health data includes longitudinal pulmonary function studies for approximately 3500 underground coal miners over approximately 15 years. Analysis will be done by constructing regression models to relate cumulative respirable dust (calculated with work history information and exposure estimates made from the MSHA data) to changes in pulmonary function (FEV1 and FVC) over the study period. The models will include covariates such as age, race, smoking history, etc. The exposure estimates constructed will be provided to NIOSH for further analysis of the NCS Round Four Data. The analysis of pulmonary function studies conducted under this proposal will help delineate the effects of low level exposure to coal dust, and help assess the adequacy of the current coal standard of 2.0 mg/m3.
