Risk assessment of hearing loss caused by occupational noise exposure in an automobile manufacturing plant

Objective To assess the risk of hearing loss due to exposure to noise exposure for workers in noise operations at an automobile manufacturing plant in Tianjin, China, and to perform risk management.Methods Conduct occupational hygiene site surveys and noise exposure measurements from July to December 2023, collect medical examination data, and use ISO 1999:2013(E) Acoustics-Estimation of Noise-Induced Hearing Loss and WS/T 754-2016《Guidelines for Risk Management of Noise Occupational Disease Hazards》predict the risk of high-frequency hearing loss and occupational noise deafness for operational workers and make a risk classification.Results The noise intensity of each workshop is 79.4 dB(A) to 95.5dB(A), in which the maximum noise intensity of welding and stamping workshop exceeds the national occupational exposure limit, which is the key control point of noise hazard of this enterprise. The results of the risk assessment showed that the predicted risk probabilities of HFHL and ONID for welding workers at the ages of 40, 50 and 60 were 15.1% to 20.2%, 33.9%, 35.5% and 0.7% to 5.7%, 9.7% to 14.7%, 18.8% respectively. The predicted risk probabilities of HFHL and ONID for workers in stamping operations were 5.3% to 10.3%, 23.1%, 24.8% and 0.0% to 5.0%, 3.4% to 8.4%, 10.8% at the ages of 40, 50 and 60 years, respectively. With the exception of welding and stamping, the predicted N50 values for permanent hearing threshold displacements due to potential noise at all frequencies for workers operating in the other shops were lower than the measured values, with differences ranging from 1.0dB to 15.0dB.Conclusions The consequences of hearing loss for workers in the welding and stamping shop noise operations at this automobile manufacturing plant are more serious and require risk management.