Winter Skies Still Pose Sun Danger, Experts Warn

Skiers and other outdoor enthusiasts need to be aware that factors such as weather conditions and time of day can cause considerable variation in the levels of ultraviolet (UV) radiation during the winter, researchers say.

They analyzed data collected between 2001 and 2003 at 32 high-altitude ski resorts in western North America. They also interviewed adult guests at the resorts and looked at their clothing and equipment in order to assess their level of sun protection.

Average UV levels at the ski resorts were moderately low but varied substantially, the researchers found. Clear skies, time close to noon, and more hours of daylight as the ski season progressed were the strongest predictors of increased UV radiation. The researchers also found minor associations between higher UV radiation and altitude, longitude and temperature.

However, elevated UV levels were not associated with increased use of sun-protection measures, such as sunscreen lip balm, application of sunscreen 30 minutes before skiing, wearing a head cover with a brim, or wearing gloves.

The study did find that as UV levels increased, adults were more likely to wear sunscreen with a minimum 15 SPF and to reapply it after two hours, and more likely to wear sunglasses or goggles. Men were more likely than women to use sunscreen.

"Skiers and snowboarders evidently monitor outdoor alpine environments in two ways, for sun protection and cold protection," wrote Peter A. Andersen, San Diego State University, and colleagues in a news release from the publisher. "For sun protection, they rely mainly on clear skies as a UV cue. They correctly link clear skies with the need for UV protection and use and reapply more sunscreen because UV is present on clear days."

But decisions about protective clothing appear to be based on inclement weather (staying warm) rather than elevated UV levels.

Commenting on the findings, Dr. Doris Day, a dermatologist at Lenox Hill Hospital in New York City, said the research shows that people who engage in outdoor sports are at higher risk for sun damage and skin cancer than they may realize.

"It highlights the importance of counseling patients to wear UV protection every day all year-round, especially if they are participating in outdoor activities at higher altitudes, and especially if they are at higher risk for skin cancer," Day said.

Andersen and his team agreed that more needs to be done to educate winter sports enthusiasts on the sun's dangers.

"More sophisticated sun safety promotions are needed that teach people both to take precautions and to judge accurately when UV is high," the authors conclude. "In future safety promotions, adults should be encouraged to wear sunscreen on cloudy days because UV is still high and conditions can change rapidly. They need reminders to rely more on season and time of day when judging UV and the need for sun safety," the researchers concluded.

The study appears in the November issue of the journal Archives of Dermatology.

More information

The American Cancer Society has more about sun safety.

-- Robert Preidt

SOURCE: Doris Day, M.D., Lenox Hill Hospital, New York, N.Y.; JAMA/Archives journals, news release, Nov. 15, 2010