RISK ASSESSMENT FOR THE HARMFUL EFFECTS OF IMMUNOTOXIC AGENTS ON THE IMMUNOLOGICAL RESISTANCE TO INFECTIOUS-DISEASES - ULTRAVIOLET-LIGHT ASAN EXAMPLE

Risk assessment comprises four steps: hazard identification, dose-resp onse assessment, exposure assessment and risk characterization. As an example we have assessed the risk of decreased host resistance to infe ctions due to effects of the immunotoxic agent - ultraviolet light. We have analysed effects of UVB radiation on basal immune functions in r ats and man, and the immunological resistance to infectious diseases i n rats. Non-threshold mathematical methods were used in order to estim ate the risk for the human population after increased exposure to UVB radiation. These data demonstrate that UVB radiation, at doses relevan t to outdoors exposure, may affect the immunological resistance to inf ectious diseases in human individuals. This study may also provide a b asis for a strategy to assess the risk of adverse effects of exposure to immunotoxic agents. (C) 1997 Elsevier Science Ireland Ltd.