ground coal mines. It can also be used at surface and metal or nonmetal mines and in other industries where there is exposure to airborne particles.
Another signal accomplishment is a significant reduction in exposure to respirable coal mine dust with consequent reduction in the prevalence of CWP. In 1970, exposure to dust was about 6 mg/m3 for continuous miner operators. Now, exposure at most continuous mining sections is about 1 mg/m3. Reductions have been achieved on longwall sections, though not on a similarly dramatic scale (Weeks, 1993). As a consequence, the prevalence of CWP among experienced coal miners was 11 percent in 1970a and, according to the most recent data, is now 2.6 percent (Pon et al., 2003). This improvement was accomplished through the combined efforts of many including the Mining Program, which developed and made information available on many practical, feasible, and effective means of reducing exposure to dust in coal mines. This is a noteworthy and unqualified success story.