Impact of Long-Wavelength Ultraviolet A1 and Visible Light on Light-Skinned Individuals.
Photochemistry and Photobiology
Solar radiation is known to be a major contributor to the development of skin cancer. Most sunscreen formulations, including those with broad spectrum, offer minimal protection in long-wavelength ultraviolet A1 (UVA1; 370-400 nm) and visible light (VL; 400-700 nm) domain. There is limited information regarding the impact of this broad waveband (VL + UVA1, 370-700 nm) on those with light skin. In this study, ten healthy adult subjects with Fitzpatrick skin phototypes I-III were enrolled. On day 0, subjects' lower back was exposed to a VL + UVA1 dose of 480 J cm-2 . A statistically significant increase in erythema immediately after irradiation compared with subjects' baseline nonirradiated skin was observed. Clinically perceptible erythema with VL + UVA1 is a novel finding since the erythemogenic spectrum of sunlight has primarily been attributed to ultraviolet B and short-wavelength ultraviolet A (320-340 nm). The results emphasize the need for protection against this part of the solar spectra and warrant further investigation.
Kohli I, Zubair R, Lyons AB, Nahhas AF, Braunberger TL, Mokhtari M, Ruvolo E, Lim HW, Hamzavi IH. Impact of Long-Wavelength Ultraviolet A1 and Visible Light on Light-Skinned Individuals. Photochem Photobiol. 2019 Nov;95(6):1285-1287. doi: 10.1111/php.13143. Epub 2019 Aug 23. PMID: 31344760.