You know you should wear sunscreen when you go out in the sun for any significant amount of time. Heck, the advice is up there with “Don’t run out in the street,” “Wear your seatbelt,” and “Don’t eat that gum you found on the sidewalk.” But according to new research, most people don’t regularly apply sunscreen — and when they do, they don’t use enough, which diminishes the product’s effectiveness.
A sunscreen’s SPF depends on the thickness of the layer applied. Studies show that people typically apply a thinner layer of lotion than experts recommend, resulting in an SPF that’s 20 to 30 percent less than the label says.
Tests that determine SPF use a standard layer of 2 milligrams of sunscreen per square centimeter. A recent study, however, observed 50 subjects applying different types of sunscreen, and found that people apply only 1.1 milligram of lotion sunscreen, 1.6 milligrams of spray sunscreen, and .35 milligrams of stick sunscreen per square centimeter of skin. (Watch the video above for three tips on how to apply sunscreen so that you reap its full protection from harmful ultraviolet rays.)
Improper application is only one problem with sunscreen use. Fewer than 30 percent of women and 15 percent of men wear sunscreen on their face and body when they go out in the sun, according to a new study from the Centers for Disease Control and Prevention (CDC), published today in the Journal of the American Academy of Dermatology.
Study author Dawn Holman, MPH, behavioral scientist with the CDC’s Division of Cancer Prevention and Control, underscores that applying sunscreen is only one part of protecting your skin from the sun’s harmful rays. “In the real world, we know that in addition to sunscreen, you’re going to need other forms of protection [such as hats and long clothing] to make sure you’re fully protected and are taking care of your skin when you’re outdoors,” she tells Yahoo Health.
It’s important to note that the 4,000 adults surveyed the CDC study weren’t simply asked, “Do you use sunscreen?” Rather, the subjects were asked how often they used sunscreen on their face, body, or both when they went outside on a warm sunny day for more than an hour. Anyone who replied “always” or “most of the time” was classified as a regular sunscreen user.
“We really want to get at people’s sun protection when they’re going to be outside for an extended period of time,” Holman explains. This allowed researchers to assess behavior when people are spending a lot of time outdoors and have a higher risk for sun damage.
The study also looked at sunscreen application on the face and body separately. About 43 percent of women said that they applied sunscreen to the face, compared with 18 percent of men. Men were also less likely to apply sunscreen to exposed skin on the body compared to women.
Related: The Best Sunscreen for Your Face
Even a diagnosis of skin cancer in the past year didn’t move the needle much. Approximately one-third of men and half of women with recent skin cancer applied sunscreen to both the face and body when they went out in the sun.
Although the study didn’t specifically ask why people didn’t use sunscreen, Holman says that the data offers some clues that might help explain the findings.
For one, low sunscreen use among men is consistent with other research. “There’s some evidence to suggest that men may see sunscreen use as kind of a more feminine behavior because it is a lotion or cream they’re applying, so for some, they may just see that as something as women do,” Holman says. That may change with products that specifically target men, she adds.
People with lower household income were less likely to report regularly using sunscreen. “That could suggest that the cost of sunscreen might be a barrier to regular use for some people,” Holman says.
In addition, nearly 40 percent of people surveyed weren’t sure if their sunscreen offered broad-spectrum protection. Experts recommend a broad-spectrum sunscreen to protect against both UVA and UVB rays. UVB rays cause skin burning, while UVA rays cause aging and wrinkles. Both types are linked to skin cancer.
“We encourage that sunscreen use be used in combination with other forms of protection,” Holman continues, “including staying in the shade when you’re outdoors if possible, using clothing for protection, and wearing a wide-brimmed hat to protect the top of your head, neck, face, and ears.”
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