The Interplay Between Solar Radiation, Climate Change and Immunotoxicants in Relation to Immune Response Modulation: A Concern for Outdoor Workers’ Health

Abstract

Immune response may be dysregulated at multiple levels for multiple reasons, spanning from congenital defects to diseases, medical treatments, environmental and occupational exposures. The consequences of immune dysregulation, especially in the case of mild immune dysfunction, are not easy to predict, being dependent on several factors, but may be subtle in most cases. Adverse health outcomes like an increased susceptibility to infections, a higher risk of cancer or the development of autoimmune diseases may occur. Outdoor workers are exposed to several risk factors, partly depending on the working activity or the job performed and partly due to the features and variability of the outdoor environment itself. Outdoor environment generally implies the exposure to severe thermal conditions, meteorological agents, environmental pollutants and solar radiation. Some volatile organic compounds, heavy metals and many pesticide display immunotoxic properties. Solar radiation itself, through the UV component, may induce immunosuppressive effects, both locally and systemically. The ongoing climate change may have a profound impact on the levels of exposure to air pollutants, pesticides, solar radiation, biological agents and disease vectors. A detailed evaluation of the combined exposure to the above-mentioned risk factors is very difficult, given the number of factors involved, the spatial and temporal variability of exposure and the high number of jobs potentially conducted outdoor, but may contribute to the definition of the “exposome” for outdoor workers. The net effect on the immune response modulation and the occurrence of the related potential adverse health outcomes are hard to predict, but this topic is of great importance for a full implementation of occupational health and safety regulation in the case of outdoor workers. This implies an integrated approach in risk assessment, a detailed evaluation of the health status during health surveillance (with particular reference to the immune function) and a careful choice of a suitable combination of preventive and protective measures at individual level.