Beware Halogen Bulbs

AS THE OZONE LAYER THINS, PEOPLE MAY SPEND more time indoors to avoid the skin cancers and cataracts likely to result from more ultraviolet light reaching the earth’s surface. That strategy could backfire. Like the sun, the high- intensity quartz-halogen lights used increasingly in homes and offices emit ultraviolet as well as visible light, and there is now evidence that they, too, can cause skin cancer.

Two scientists at the University of Genoa, Italy, noted that the rays coming from unshielded quartz-halogen lamps can induce mutations in the DNA of bacteria. Since genetic mutations are one cause of cancer, they decided to move up a few rungs on the evolutionary ladder. They subjected specially bred hairless mice to the lights 12 hours a day for a year and found that every one developed skin tumors — most benign, but some cancerous. The research, reported in the British journal Nature, involved only a handful of mice, so it was labeled a pilot study. But the results were so striking that the authors recommended installing UV filters on halogen lamps already in use and requiring that all new ones come equipped with such filters (some already are).