Introduction Open surface mining is utilized to extract limestone for the production of cement. Using heavy motor vehicles (HMVs) and other earthmoving equipment, skilled personnel [HEOs] perform this operation. HEOs are exposed to significant noise (80–90 dBA) emitted by these HMVs for about 8 hours a day. We report the results of pure tone audiometry (PTA) conducted on HEOs as part of a health surveillance programme.

Methods In this observational study, 108 HEOs working in a large scale mining industry in South India were assessed for noise induced hearing loss {NIHL}. Standard guidelines were followed and PTA was performed using a NIOSH approved audiogram machine. For this analysis, we selected HEOs between the ages of 45 and 57 years, with 10 or more years of service. These results were compared with 106 age matched employees, who were involved in non-mining activity in the same industry with the same amount of noise exposure but from different sources. Results were validated using standard statistical tools.

Result Results revealed 60% (64/108) of the HEOs suffered NIHL. Of these the impact on the left side was found to be more pronounced for 90% (58/64) versus 10% (6/64) in the right ear. In the comparative group of 106 non-mining employees 55% (59/106) had abnormal audiogram reports but with no specific inclination to the right or left side.

Discussion NIHL is common in the mining industry. The observed laterality in hearing loss among HEOs is likely multi-factorial and can be attributed to the presence of the engine on the left hand side in the Indian vehicles, the failure to sound proof the operator’s cabin and/or comply with the issued personal protective equipment {PPE}. Our results underscore the importance of the need for compliance with the use of PPEs and vehicular upgrade and maintenance.