Risk assessment of recordable occupational hearing loss in the mining industry.

The study counted recordable hearing loss incidences, not unique affected miners. It could not tell whether different miners at the same mine developed hearing impairment or whether the same miner had multiple hearing shifts. It included only mine operator employees and excluded contractors, so it does not describe the whole mining workforce. Occupation-level incidence rates could not be calculated because the data did not provide the number of employees by occupation. Occupation counts combine risk and employment size. Mining experience was available only for miners who had a standard threshold shift, not for the entire workforce, so experience categories may be biased. The analysis relied on reported recordable hearing loss rather than audiograms, so under-reporting and differences between recorders are likely.

Do not conclude that hearing conservation programmes failed. The study counted recorded hearing loss cases, not unique miners, and it did not measure programme implementation, noise exposure, or non-occupational noise.