Ultraviolet erythemal radiation in Central Chile: direct and indirect implication for public health

Ultraviolet radiation (UV) plays a key role in the photochemistry in the atmosphere. UV has a detrimental impact on human health from direct exposure to sunlight and indirect effect by enhancing photochemical pollutants. Characterizing the levels of solar UV and its role in the production of photochemical pollutants is important to provide awareness of its negative health effects on the human population. Four years (2015–2018) of ultraviolet erythemal radiation (UVER) measurements for Santiago, Chile, were analyzed, and the potential impact of UVER on human health were assessed from both direct and indirect effects. High values of UVER occurred from spring to early autumn, with a maximum of 0.33 Wm⁻². Ultraviolet index (UVI) values ≥ 11 were observed in 17% of the days, while UVI ≥ 6 accounts for up to 50% of the days during the observation period. The population in the Metropolitan Region of Santiago (Central, Chile) is exposed to high levels of UVER, increasing the risk of severe sunburn and developing skin cancer. Tropospheric ozone had a positive correlation with ultraviolet erythemal radiation, indicating an increment of 27 ppbv in ozone concentration when UVER levels were above 0.10 Wm⁻² (UVI = 4). Incoming sunlight reaches the surface of Central, Chile, energetically enough to cause sunburn and increase the levels of tropospheric ozone from late spring to early autumn. This study provides useful information for public awareness and for adopting strategies to reduce the negative impacts on the human population from direct exposure to sunlight and its role in the production of photochemical pollutants.