Introduction Immunotoxicants may interfere with one or more mechanisms involved in the elicitation of the immune response. Occupational exposure to solar radiation may exert an immunosuppressive effect, both locally and systemically, while the ongoing climate change may alter the occupational exposure to both solar radiation and a number of immunotoxicants.

Methods Literature review on occupational exposure to immunotoxicants as well as to solar radiation and climate change.

Results Metals, solvents, some pesticides and other categories of chemicals currently used in or released by working processes are immunotoxic. Outdoor workers may be simultaneously exposed to both immunotoxicants and solar radiation. Moreover, a changing climate may increase or, depending on some factors involved, decrease the occupational exposure to both immunotoxicants and solar radiation. The net effect on the overall immune response is difficult to predict, depending on the combination and levels of the exposures involved and the outcome considered (for instance immune response to pathogens vs allergic/sensitisation reactions).

Discussion The protection of outdoor workers from the effects due to combined exposure to immunotoxicants, solar radiation and variables connected to climate change needs a careful assessment of all the factors involved, having care to acquire the immune profile of the worker during the health surveillance, through both conventional and innovative approaches. In addition, co-exposure to chemical or physical agents (e.g. irritants, sensitizers, high temperatures and humidity) modulating the effect/s of a given level of exposure to a single immunotoxicant or to a combination of immunotoxicants has to be taken into account. As a perspective, the implementation of this topic may contribute to define the ‘exposome’ of important categories of outdoor workers.