Occupational and environmental chemical risk assessment in a changing climate: A critical analysis of the current discourse and future perspectives

The increase in atmospheric greenhouse gases (GHGs) is resulting in global warming and climate change that, according to various climate change models, could result in changes in region-specific rainfall patterns, floods, sea levels, as well as infectious and heat-­related disease patterns. However, the indirect effects of climate change on chemical risk assessment, which forms the basis for both occupational and environmental health, have not received commensurate attention. Therefore, this study presents a content analysis of the current discourse on implications of climate change on occupational and environmental chemical risk assessment. Since temperature and climatic zones affect the toxicity of substances, cclimate change has potential to affect toxicity of chemicals. Climate change can alter absorption, distribution, metabolism, and excretion (ADME) of chemicals that can in turn influence the internal dose. These effects can be captured in Adverse Outcome Pathways (AOPs), which depict linkages between molecular initiating events and the subsequent cascade of responses in individuals or populations. Furthermore, climate change is expected to result in novel climate and ecological systems that may not have current analogies in terms of their temperature and precipitation regimes. A change in climate will also affect exposure to toxic substances mediated through effects on various transport, degradation, dissipation and fate processes. Ultimately, climate change will have implications on the validity of occupational and environmental chemical risk assessment through space and time. Consequently, occupational and environmental chemical risk assessment will need to consider multiple stressors at ecological level using conceptual cause–effect diagrams at spatial and temporal scales in order to account for both direct and indirect effects of climate change, whose magnitude will depend on the extent to which current conditions are altered