The preventable burden of work-related ill-health.

Background: The fraction of ill-health overall attributable to occupational conditions has not been extensively evaluated, thus contributing to the perception of a lesser relevance of education and research in occupational health in respect to other fields of medical research and practice. Aims: To assess the relevance of work-related conditions on the aetiology of human ill-health in different health domains. Methods: We extracted the risk estimates associated with heritability and with occupational risk factors for chronic lymphocytic leukaemia (CLL), major depressive disorder (MDD) and long QT syndrome (LQTS) from 13 published international reports. The selection criteria for the eligible studies were: genome-wide studies, or studies of the occupational risk factors associated with one of the three diseases of interest. We calculated and compared the respective population attributable fraction for the combined occupational risk factors, and for heritability. Results: We estimated that occupational risk factors would account for 12% (95% confidence interval (CI) 4-19) of CLL, 11% (95% CI 7-15) of MDD and 10% (95% CI 2-13) of LQTS burden in the general population. The corresponding figures for heritability would be 16% (95% CI 11-22), 28% (95% CI 20-5) and 17% (95% CI 7-27). Conclusions: More efforts in capacity building and research in occupational health are warranted aiming to prevent ill-health and to preserve a productive life for the ageing work population.