This study examines the effectiveness of the dust standards set by the Coal Mine Health and Safety Act of 1969 in preventing obstructive lung disease by considering the exposure-response relationship in a group of miners whose exposure began in or after 1970 when the regulations took effect. Accurate and precise estimates of exposure for the cohort were developed using compliance data collected by the Mine Safety and Health Administration (MSHA). Adjustments in the data were made to account for several potential biases. Arithmetic mean concentrations were estimated within work categories defined by mine, occupation and year and decreasingly-specific categories, occupation/year, mine/year, and year. The mine/occupation/year estimates were combined with the occupation/year estimates so as to minimize the mean squared error of the resulting mean. Exposing-response relationships were examined among 1270 miners from the National Study of Coal Workers' Pneumoconiosis. Cross-sectional and longitudinal associations between cumulative exposure and pulmonary function test results (FVC, FEV\sb1, and FEV\sb1/FVC) and respiratory symptoms were modeled using linear and logistic regression while controlling for smoking. The results over a 15 year exposure period indicated statistically significant positive associations of cumulative exposure with decrements in FEV\sb1, FEV\sb1/FVC, the likelihood of these indices being less than 80% of predicted, and symptoms, including chronic bronchitis, breathlessness and wheeze with shortness of breath. The estimated effect of exposure of FEV\sb1 was 5.5 ml per mg/m\sp3-years which was substantially larger than previously reported estimates. However, examination of PFTs within five years of beginning work demonstrated a rapid initial exposure-related loss of both FVC and FEV\sb1 and no additional exposure-related loss over the following 10 years. The results of the study suggest that exposure to coal mine dust at concentrations present since the CMHSA regulations were put into effect have not been completely successful in preventing respiratory effects. Determination of the long-term significance of the initial exposure-response relationship observed requires additional follow-up of this cohort.Ph.D.Industrial HealthUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/105283/1/9116296.pdfDescription of 9116296.pdf : Restricted to UM users only
