A Critical Assessment of Boundary Limits of Health Risks Associated with WBV Exposure Based on Field Studies on LHD Vehicles in Indian Underground Coal Mines.

Purpose: The mining sector plays a pivotal role in meeting global resource demands, necessitating the extensive use of heavy earth-moving machinery (HEMM). Among these, load-haul-dump (LHD) mining vehicles are vital but expose operators to whole-body vibration (WBV) and shocks during their duties. Research indicates potential health risks associated with occupational WBV exposure, including musculoskeletal disorders. Evaluating these risks typically employs ISO 2631-1:1997, which, however, has limitations in addressing long-term exposure and shock effects.

Methods: This study quantifies the health risks of LHD operators in Indian underground coal mines using ISO 2631-5:2018 and compares it to ISO 2631-1:1997. The methods for risk quantification from WBV vary between the two standards, leading to a comprehensive comparison. In addition, a cross-sectional study was undertaken to assess self-reported musculoskeletal pain among LHD operators.

Results: The results were compared in accordance with frequency-weighted root mean square (RMS) values, vibration dose values (VDV), daily compressive dose (S_d ^A), and the risk of injury (R^A) factor. The assessment using A(8), VDV, S_d ^A, and R^A produced diverse evaluations, influencing varying perspectives on occupational health despite significant risks. ISO 2631-5:2018 consistently suggested a lower health risk for LHD operators as opposed to ISO 2631-1:1997. Seat effective amplitude transmissibility (SEAT) values showed amplification of vibration in the range of 4-8 Hz. Self-reported musculoskeletal pain indicated the prevalence of discomfort among operators.

Conclusion: The study emphasizes a cautious approach when interpreting results and shaping guidelines to ensure sustainable development through the well-being of mining industry workers.