Health inequities related to occupational health impacts of climate change

Background: Excessive heat exposure in workplaces is a well known occupational health hazard. In the USA workplace heat deaths occur primarily among immigrant agricultural workers. Heat waves in Europe and regular heat conditions in tropical countries also cause heat stroke among manual workers. Climate change will make this situation worse, challenging health equity. A recent global economic analysis predicted that the greatest impact on labor productivity losses would result from increasing heat exposure.

Methodology: Global modeling data on temperature and humidity were used to estimate the monthly heat stress WBGT index at different time points during typical days currently and in the future (2030 and 2050). Available exposure-response relationships for heat impacts on work capacity at different levels of work metabolic rate were then used to calculate the predicted loss of work capacity. The losses in work capacity for workers in light jobs and in heavy jobs were compared to establish an occupational heat inequity index (OHII).

Results: The OHII predicts current occupational health challenges from workplace heat in the tropical parts of the world. For example, in South-East Asia workers in heavy labor lose twice as much work capacity due to workplace heat as the workers in lighter jobs. This inequity is estimated to double by 2050. OHII predictions for the different tropical regions will be presented.

Conclusions: Occupational health needs to be closely analyzed in relation to climate change, and an important effect is loss of work capacity, which has a major impact on health and social equity.