A comparison of airborne dust concentrations in the South Wales coalfield in the period 1943-1975

During the period reviewed, various sampling instruments were used which measured different parameters of the dust cloud. As the current airborne dust standards are in gravimetric units as measured with the MRE sampler, this instrument has been used as a standard against which the Soxhlet, PRU handpump, standard thermal precipitator, and long running thermal precipitator have been compared. Survey results for various years were converted to mass units and compared with those for 1970 and 1975. Mean concentrations showed a threefold reduction, and the prevalence of pneumoconiosis decreased.