Contribution of UVA to the effects of sunbeds - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2023

Contribution of UVA to the effects of sunbeds

Résumé

A characteristic of UV lamps found in sunbeds is that their spectrum is more intense and richer in UVA (320-400 nm) than natural sunlight. The latter wavelength range has long been considered as negligible compared to more energetic UVB (280-320 nm). However, a growing amount of information is now available showing that UVA exhibits deleterious effects in human skin. A well-documented phenomenon is photoaging associated with oxidative stress that degrades components of the dermal extracellular matrix. Release of oxidizing species by photosensitized processes is also involved in many processes such as lipid peroxidation and protein degradation. DNA is another target of UVA-mediated oxidative stress with formation of oxidized bases and strand breaks. Interestingly, it is now well established that UVA is weakly absorbed by DNA where it induces the formation of pyrimidine dimers like UVB, although with a lower efficiency. UVA-induced formation of pyrimidine dimers can also occur in the dark through oxidative processes like the formation of melamine peroxides. UVA exhibits also systemic properties such as immunosuppression. Interestingly, UVA can act in synergy with UVB. For example, it is now well established that UVA, likely through protein oxidation, degrades DNA repair enzymes and hampers the removal of UVB-induced photoproducts. The combination of these different mechanisms would be synergic in terms of mutagenesis. These observations strongly support a possible role of UVA in the increased frequency of melanoma in sunbed users. Altogether, it appears that UVA is not a harmless physical agent. It is actually classified as carcinogenic to humans. Since it is now well documented than the pigmentation induced by artificial sunlight does not afford skin photoprotection, use of sunbeds results in a voluntary exposure to a damaging agent without health benefit.

Domaines

Toxicologie
Fichier non déposé

Dates et versions

hal-04355398 , version 1 (20-12-2023)

Identifiants

  • HAL Id : hal-04355398 , version 1

Citer

Thierry Douki. Contribution of UVA to the effects of sunbeds. 20th Congress of the European Society for Photobiology, European Society for Photobiology, Aug 2023, Lyon, France. ⟨hal-04355398⟩
5 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More