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

Abstract

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 (Sd A), and the risk of injury (RA) factor. The assessment using A(8), VDV, Sd A, and RA 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.