Occupational epidemiological characteristics of noise-induced hearing loss and the impact of combined exposure to noise and dust on workers' hearing-a retrospective study

The aim of the study was to investigate the occupational epidemiological characteristics of hearing loss among noise-exposed workers through a cross-sectional study and to explore the impact of combined noise and dust exposure on workers' hearing loss through a longitudinal study. This cross-sectional study revealed that the risk of speech-frequency hearing loss increases with age (OR = 1.096, 95%CI = 1.081-1.111). Independent factors influencing high-frequency hearing loss include sex, age, hazardous factors, industry category, and enterprise size. Scientific research and technical services (OR = 1.607, 95%CI = 1.111-2.324), wholesale and retail (OR = 2.144, 95%CI = 1.479-3.107), manufacturing (OR = 1.907, 95%CI = 1.429-2.545), and other industries (OR = 1.583, 95%CI = 1.002-2.502) are risk factors for high-frequency hearing loss, whereas being female (OR = 0.297, 95%CI = 0.236-0.373) is a protective factor against high-frequency hearing loss. Independent factors influencing occupational noise-induced hearing loss include sex, working age, hazardous factors, industry category, smoking, and drinking, with the risk of occupational noise-induced hearing loss increasing with working age (OR = 1.045, 95%CI = 1.031-1.058). Noise and dust work (OR = 1.271, 95%CI = 1.011-1.597), other work (OR = 0.619, 95%CI = 0.479-0.800), manufacturing (OR = 2.085, 95%CI = 1.336-3.254), other industries (OR = 2.063, 95%CI = 1.060-4.012), occasional smokers (OR = 0.863, 95%CI = 0.652-1.142), regular smokers (OR = 1.216, 95% CI = 0.987-1.497), and excessive drinkers (OR = 2.171, 95%CI = 1.476-3.193) are risk factors for occupational noise-induced hearing loss, whereas being female (OR = 0.496, 95%CI = 0.347-0.709) is a protective factor against occupational noise-induced hearing loss. The longitudinal study revealed differences in pure-tone hearing threshold test results at 500 Hz, 1,000 Hz, 3,000 Hz, 4,000 Hz, and 6,000 Hz in both ears before and after enrollment among noise-exposed workers (