Effects of Varying Doses of UV on Mammalian Skin: Simulation of Decreasing Stratospheric Ozone.
NIOSH 1980 May:664-672
The effects on the skin of different doses of ultraviolet (UV) radiation and of depleting the ozone (10028156) layer were studied in mice. Albino-hairless-mice were irradiated with solar simulating UV light and with monochromatic light at selected wavelengths for 5 consecutive days each week. Filters were used in the ozone depletion experiments to mimic the effect of different ozone layer thicknesses. Animals were killed at intervals up to 30 days after exposure began, and clinical and histological responses were graded. Monochromatic bands of UV radiation induced burning and precancerous lesions at 280, 301, 307, and 313 nanometers (nm). Burning and intense macular erythema were most pronounced at 307nm. No precancerous lesions occurred at 366nm, despite a much higher dosage. In the solar simulator experiments, early malignant changes were induced in 5 percent of the animals exposed to ultraviolet-B (UVB) alone, in none of the animals exposed to UVA alone, and in 80 percent of the animals exposed to UVB and UVA combined. In the ozone depletion experiments, precancerous changes were produced at a constant dose only when no filter and a 0.5 millimeter (mm) filter were used. Effects due to 2.0 and 3.0mm filter combinations eventually regressed back to mild erythema or disappeared completely. The authors conclude that the UVB component of ultraviolet radiation is primarily responsible for cancerous changes, that UVB augments the carcinogenic activity of UVB, and that a time dose reciprocity does not exist for the effects of exposure to ultraviolet light.
Nonionizing-radiation; Skin-exposure; Laboratory-animals; Oxidizers; Radiation-exposure; Radiation-hazards; Radiobiology;
Proceedings of the First NCI/EPA/NIOSH Collaborative Workshop: Progress on Joint Environmental and Occupational Cancer Studies, May 6-8, 1980, Rockville, Maryland, H. F. Kraybill, I. C. Blackwood, and N. B. Freas, Eds. National Cancer Institute, Environmental Protection Agency, National Institute for Occupational Safety and Health