US mines with the most noise samples over the legal limit

Ridge Deep Mine has the highest share of MSHA noise samples over the permissible exposure limit of any US mine on record, at 70% of 37 samples measured above the 90 dBA limit. Next are Nelms Mine - Cadiz Portal (52%) and Belmont County Strip - Fox Farms (51%).

US mines ranked by the share of their MSHA noise samples that measured over the 90 dBA permissible exposure limit. Noise-induced hearing loss is the most frequently reported occupational illness in mining. Click a mine for its full sampling and compliance record.

MSHA reports each noise sample as a dose against the allowance, so a dose over 100% is over the limit. A sample over the PEL is an exposure measurement, not a violation and not a compliance judgment. It is also a measurement of the workplace, not of what reached the miner's ear: hearing conservation programs and the hearing protection worn during the shift are recorded separately in MSHA's data and are not reflected in this share. Only mines with at least 30 noise samples on record are ranked, so a handful of readings cannot drive the rate. Noise is sampled at coal, metal, and nonmetal mines alike, so this ranking covers all of them.

Looking at other exposures? See coal mines ranked by silica in their dust samples or coal mines ranked by reported methane. For enforcement, see mines ranked by MSHA violations.