Measurements of dust concentration showed that the concentration
of total suspended particulate matter produced by
the cutting drums of the longwall shearer with the use of
water spraying was over 170 mg/m3, while the concentration
of respirable fraction of dust was about 12 mg/m3. When the
air-and-water spraying system was used, the measured total
suspended particulate matter was found to be reduced to 100
mg/m3, while the concentration of respirable fraction did not
exceed 1 mg/m3.