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.


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.

Publication types

  • Letter
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Dose-Response Relationship, Radiation
  • Erythema*
  • Humans
  • Light / adverse effects*
  • Skin / radiation effects*
  • Skin Pigmentation*