Objectives: Statistics on prevalence of pneumoconiosis among working underground coal miners from data collected as part of a large national radiographic surveillance program between 1970 and 1986 are presented. The main intent was to examine the time-related trend in prevalence over this period, which coincides with historically low dust levels mandated by federal act.
Methods: Tenure-specific prevalence rates and summary statistics derived from them for four consecutive time intervals within the 16-year period were calculated and compared.
Results: The results indicate a reduction in pneumoconiosis over the life of the program. This trend is similar to that seen in epidemiologic studies undertaken concurrently.
Conclusions: Although low participation in the surveillance program and other problems complicate the findings, it appears that reductions in dust exposure mandated by federal act in 1969 have led to lower prevalence of pneumoconiosis among underground coal miners.