Wavelength dependent responses of primary human keratinocytes to combined treatment with benzo[a]pyrene and UV light.

The major risk factor for skin cancer is exposure to UV radiation from sunlight, but other environmental exposures may also play a role in combination with UV. We have studied the effects of combined exposure of primary human skin cells in vitro to UVA, UVB or UVC with benzo[a] pyrene (BaP), an environmental carcinogen. Normal human keratinocytes were exposed to 5 microM BaP for 24 h followed by either 1 kJ/m(2) UVA, 100 J/m(2) UVB or 10 J/m(2) UVC.