Occupational noise. A determinant of social inequalities in health

Occupational noise exposure is common in many workplaces and a well-known cause of noise-induced hearing loss and related to tinnitus and hyperacusis (hypersensitivity to sound), as well as other health outcomes, such as distress, hypertension, and occupational injuries. Hearing loss and many health conditions are more frequent in lower socioeconomic groups. Loud occupational noise is generally also more common among blue-collar workers, while white-collar workers are virtually unexposed. Therefore, occupational noise exposure would seem like a plausible cause of socioeconomic inequalities in hearing and other health outcomes; in other words, occupational noise could be a mediator (intermediate variable) between socioeconomic position and health. However, hardly any studies have investigated the impact of occupational noise exposure on social inequalities in hearing, and none seems to have studied its impact on other health outcomes. One study found that the association between socioeconomic position and hearing loss was reduced after controlling for occupational noise exposure, suggesting that occupational noise to a considerable extent could explain the association between occupation and hearing loss. There is a lack of studies addressing the impact of occupational noise exposure on social inequalities in health; thus, more studies specifically designed to investigate this topic are needed.