Summary
An animal experiment is presented in which three groups of albino hairless mice (Skh-hr 1) were exposed to daily doses of either UV-B or UV-A to study carcinogenesis. The UV-A was filtered carefully so as to eliminate contaminating UV-B. The doses required for acute effects (erythema and edema) were also determined for the two radiation modalities. In order to study the relative carcinogenic risks of exposures to UV-A and to UV-B, for both modalities, the doses causing skin tumors were compared to the doses required for eliciting acute effects in the skin.
In the experiment on carcinogenesis all animals developed tumors, the ones exposed to UV-A as well as the ones exposed to UV-B. A striking difference, however, was that the induction times of the first tumors showed a larger spread in the mice exposed to UV-A than in the UV-B groups. Also, the development of successive tumors in each individual mouse was more spread in time in the UV-A group. A second difference between the effects on the skin was that in the animals exposed to UV-B no skin reactions were seen until the tumors developed. However, in most UV-A exposed animals, a marked scratching, probably caused by severe itching, and hyperkeratosis preceded the development of the tumors.
Histologically at least 60% of the larger tumors induced by UV-A appeared to be squamous cell carcinomas. This finding is very similar for UV-B induced tumors. The elastic fibers in the UV-A exposed animals were also examined and actinic elastosis was observed.
Experience has proven that the doses for acute affects in man and mouse are at least proportional to human tanning doses. Comparison of the doses of UV-A and UV-B required for the induction of tumors and for acute reactions of the skin, therefore, leads to the conclusion that the carcinogenic risks of tanning by UV-A and of tanning by UV-B are in the same order of magnitude.
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References
Berger H, Kaase H (1983) Zur Frage des Karzinomrisikos neuer UV-A Strahler. Z Hautkr 58:63
Berger H, Tsamboas D, Kaase H (1980) Experimentell aktinische Elastose durch chronische Exposition mit gefilterter UV-A-Strahlung. Z Hautkr 55:1510–1527
Blum HF (1959) Carcinogenesis by ultraviolet light. Princeton University Press, Princeton NJ
Bruls WAG, Slaper H, Van der Leun JC, Berrens L (1984) Transmission of human epidermis and stratum corneum as a function of thickness in the ultraviolet and visible wavelength. Photochem Photobiol 40:485–494
Cole CA, Davies RE, Forbes PD, D'Aloisio LC (1983) Comparison of action spectra for acute cutaneous responses to ultraviolet radiation: man and albino hairless mouse. Photochem Photobiol 37:623–631
Cole CA, Forbes PD, Davies RE (1986) An action spectrum for UV carcinogenesis. Photochem Photobiol 43:275–284
De Gruijl FR, Van der Meer JB, Van der Leun JC (1983) Dose-time dependency of tumor formation by chronic UV exposure. Photochem Photobiol 37:53–62
Everett MA, Yeargers E, Sayre RM, Olson RL (1966) Penetration of epidermis by ultraviolet rays. Photochem Photobiol 5:533–542
Forbes PD, Davies RE (1984) Photobiology of experimental ultraviolet photocarcinogenesis. In: Daynes RA, Spikes JD (eds) Experimental and clinical photoimmunology, vol 1. CRC Press, Boca Raton, Florida
Forbes PD, Davies RE, Cole CA (1982) Photocarcinogenesis by UVA alone. Abstract. 10th Annual Meeting of the American Society of Photobiology, Vancouver, Canada, p 66
Kaase H, Zidowitz B, Berger H (1984) Spektrale Strahlungsmessung an UV-Bestrahlungsgeräten und Experimente zur Abschätzung der Photokarzinogenese. Licht-Forschung 6:43–47
Kligman LH, Akin FJ, Kligman AM (1985) The contributions of UVA and UVB to connective tissue damage in hairless mice. J Invest Dermatol 84:272–276
Mutzhas MF, Hölzle E, Hofmann C, Plewig G (1981) A new apparatus with high radiation energy between 320–460 nm: physical description and dermatological applications. J Invest Dermatol 76:42–47
Parrish JA, Jaenicke KF, Anderson RR (1982) Erythema and melanogenesis action spectra of normal human skin. Photochem Photobiol 36:187–191
Peak MJ, Peak JG, Moehring MP, Webb RB (1984) Ultraviolet action spectra for DNA dimer induction, lethality and mutagenesis in Escherichia coli with emphasis on the UVB region. Photochem Photobiol 40:613–620
Strickland PT (1986) Photocarcinogenesis by near-ultraviolet (UVA) radiation in Sencar mice. J Invest Dermatol 87:272–275
Van der Leun JC (1987) Interactions of different wavelengths in effects of ultraviolet radiation on the skin. Photodermatology 4:257–264
Van Weelden H, De Gruijl FR, Van der Leun JC 91983) Tumors induced by UVA in mice. Abstract. 11th Annual Meeting of the American Society of Photobiology, Madison, Wisconsin, p 579
Van Weelden H, De Gruijl FR, Van der Leun JC (1986) Carcinogenesis by UVA, with an attempt to assess the carcinogenic risks of tanning with UVA and UVB. In: Urbach F, Gange RW (eds) The biological effects of UVA radiation. Praeger, New York, pp 137–146
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van Weelden, H., de Gruijl, F.R., van der Putte, S.C.J. et al. The carcinogenic risks of modern tanning equipment: Is UV-A safer than UV-B?. Arch Dermatol Res 280, 300–307 (1988). https://doi.org/10.1007/BF00440604
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DOI: https://doi.org/10.1007/BF00440604