Occupational inequalities in health: Do occupational risks matter?

In all developed countries mortality, morbidity and disability show a decreasing social gradient of risk from the less to the more advantaged occupations. The health profile of an occupation is influenced directly by the exposure to occupational hazards in the specific workplace and indirectly by the disadvantaged social position to which the occupation belongs, that may severely limit the access to goods, services, opportunities, support, information, abilities that promote health. Alternatively, illness or its predictors may influence the occupational trajectory of a person, ending in a social segregation of unhealthy workers. How much relevant is each of these explanations of occupational health inequalities? Few longitudinal studies have tried to disentangle such different mechanisms of occupational health inequalities at the same time. In a Danish sample of 5000 workers two thirds of the social class gradient with regard to worsening of self-rated health over time could be explained by differences in work environment factors (ergonomic factors and repetitive work in particular) (Borg & Kristensen, 2000). On the contrary, in the Turin Longitudinal Study, occupational exposures were able to explain the male occupational class differences in mortality only to a moderate extent, probably due to misclassification of exposure (measured by a JEM), together with the fact that mortality is a less sensitive outcome for many occupational risk factors (Mamo et al., 2005). This paper will examine and discuss the relative importance of occupational and non- occupational risk factors in explaining social class inequalities for different health outcomes, in the light of both indirect evidence coming from the determinants of health inequalities and direct evidence coming from a review of adequate studies.