Varying sensitivity of human skin fibroblasts to polychromatic ultraviolet light.

The inactivation of normal and xeroderma pigmentosum cells has been compared following exposure to environmentally relevant wavelengths of ultraviolet light or to the more commonly investigated 254-nm ultraviolet light. The sensitivity of xeroderma pigmentosum cells to polychromatic long-wavelength ultraviolet light was greatly lower than that observed using 254-nm light. Such variations in the relative sensitivities of normal and xeroderma pigmentosum cells support the likelihood that the lesions which contribute to cellular alterations induced by solar wavelengths of ultraviolet light are different from those which predominate at 254 nm.