Sunlight, PCB exposure enhance skin canc...( CHAMPAIGN Ill. Sunlight and PCB expo...)

CHAMPAIGN, Ill. Sunlight and PCB exposure can hit you where you least expect it. The combination enhances the development of non-melanoma skin cancer on parts of the body not directly exposed to the sun, according to a University of Illinois study.

Preliminary results of the research, which used the hairless mouse model of humans with non-malignant skin cancer, were presented today (March 21) in an exhibit at the 40th annual meeting of the Society of Toxicology in Nashville, Tenn. UI researchers also reported that PCB-exposed mice also ate more and grew fatter, regardless of exposure to light.

The statistical power of our experiments leads us to believe that our results likely underestimate the strength of our conclusions, said Rhian B. Cope, a professor of veterinary biosciences in the UI College of Veterinary Medicine. Because PCB-contaminated soil and sun exposure are both extremely common, we must look at this issue in humans.

In the study, funded by the American Cancer Society, researchers exposed a group of mice for 77 days to soil from a Southern Illinois landfill site contaminated with polychlorinated biphenyls and polychlorinated dibenzofurans, a PCB byproduct. Some of the mice were then exposed five days a week for 28 weeks to solar ultraviolet radiation.

Researchers found that the PCB-sunlight combination led to a rapid growth of non-melanoma tumors on the non-light-exposed undersides of the mice. The tumors were slow growing and did not turn into squamous cell carcinomas, thus demonstrating their low malignant potential, the authors noted. PCB-exposed mice kept out of the light did not develop such tumors.

By day 281, other results surfaced. Mice exposed to sunlight but not the contaminated soil had developed twice the number of skin tumors in light-exposed areas than had PCB- and light-exposed mice. It was believed that the PCB-PCDF-contaminated soil, which caused chloracne (an acne-like eruption associated with d
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Contact: Jim Barlow
b-james3@uiuc.edu
217-333-5802
University of Illinois at Urbana-Champaign
21-Mar-2002