Written by Anna Christensen, Senior Communications Coordinator, University of Arizona Cancer Center
TUCSON, Ariz. – Skin cancer is the most common type of cancer in the world, and is caused mainly by exposure to the sun’s ultraviolet rays. Phoenix and Tucson get 310 sunny days a year – a blessing and a curse.
As Arizonans transition from spring to summer, skin cancer awareness programs ramp up in concert with the swiftly escalating temperatures. By the time the mid-summer monsoons hit, these messages start to fall off our radar. When the weather once again is hospitable after fall rolls around, many of us are back to enjoying the outdoors without adequate sun protection.
Reducing our risk of skin cancer, however, is a year-round activity. In Tucson, we’re lucky to have a team of cancer experts at our fingertips. Lisa Quale, health educator at the University of Arizona Cancer Center’s Skin Cancer Institute, works with the community to help people learn the best ways to enjoy the sun’s benefits while protecting themselves from cancer-causing UV radiation.
Each Tuesday, throughout the month of August, the UA Cancer Center will present the “Top 5 Strategies for Reducing Skin Cancer Risk.” Employing these strategies in combination will give us the best protection of all.
TOP FIVE STRATEGY NO. 3: Wear Sunscreen
It might seem strange that sunscreen, that old standby in skin protection, is strategy No. 3 for reducing skin cancer risk. Sunscreen doesn’t protect you from all UV rays; that’s why sun avoidance and protective clothing are
the first lines of defense against the sun. However, sunscreen can be applied to parts of our bodies not usually covered by clothing, such as the face, ears and hands.
The UA Skin Cancer Institute recommends using sunscreen as a base – put it on first, before applying makeup or insect repellent, and apply it 20 minutes before going outside.
“Sunscreen needs time to absorb into the top layers of the skin and ‘settle’ in,” explains Quale.
Sunscreen is labeled by SPF – its sun protection factor. The SPF number indicates how long the sunscreen will protect your skin from UVB rays, which cause sunburn. Sunscreen with an SPF of 30, when correctly applied, allows a minute’s worth of UVB rays to reach your skin for every 30 minutes you’re in the sun. To avoid sunburn, SPF should be at least 30 and reapplied every two hours.
Most people do not use enough sunscreen, so they do not get the UV protection advertised on the label. Quale recommends that you apply it in two installments. “Put it on when you get up in the morning and then put on a second coat before you go outside. Not only are you going to make sure that you have enough on, but you’ll probably hit any spots you missed the first time.”
Protective ingredients in sunscreens can be divided into two types: mineral and chemical. That distinction might seem confusing – minerals are types of chemicals, after all – but the difference is that mineral sunscreen ingredients, like zinc oxide and titanium dioxide, are physical UV blocks that reflect and scatter UV rays, while chemical ingredients, like avobenzone and mexoryl, absorb and neutralize these rays.
The following tips can help you choose the best sunscreen:
- Check the ingredients for zinc oxide, titanium dioxide, avobenzone or mexoryl
- Make sure the product offers at least SPF 30, and is labeled as broad spectrum (providing protection from both UVA and UVB rays)
- If you will be in the water or sweating, check to see if it is water- or sweat-resistant
- Check the expiration date to ensure you’ll be able to use it before it expires
The UA Skin Cancer Institute doesn’t recommend any particular brand of sunscreen, as long as it meets the above criteria. Consumer Reports has independently tested and rated sunscreens to ensure they actually provide the SPF promised on the label.
Some people hate sunscreen – claiming it smells weird, feels greasy, causes acne, hurts their eyes when they sweat or interferes with makeup, among other complaints. Luckily, a range of products can address these concerns. Find a sunscreen that you like – try different products and ask friends and family if you can sample their favorites. Investing in something you like and will use will pay dividends in the future.
Sunscreen doesn’t have to be squirted out and slathered on – sunscreen also comes in spray-on and stick formulations. How do they compare to classic lotions?
“Sprays should be applied evenly to the skin and then rubbed in. If you follow the directions, sprays cover quite well,” says Quale. “Always apply it in a well-ventilated room or outside in the shade.” Never spray sunscreen directly onto your face – spray it into your hands and then apply it to your face or use a different product for your face.
As for sunscreen sticks, Quale says, “Waxy sticks go on pretty thick, so chances are you’ve used enough. I only recommend this type of product for small area spot application – ears, nose, forehead.”
Store sunscreen in a cool, dark place. Like many medications, its effectiveness starts to wane when it gets too hot or is exposed to light – making glove compartments or window sills less-than-ideal storage locations.
Top Five Strategy No. 2: Cover Up (with long sleeves, pants, sunglasses and a hat)
The UA Skin Cancer Institute recommends protecting your skin with long-sleeved shirts and pants, in dark colors, thick fabrics and tight weaves. A hat with at least a three-inch brim can cover or shade your head, face, ears and neck. When deciding what to wear, remember the following traits, which offer the most UV protection:
Tight weaves: Fabrics like denim and flannel have tight weaves, while fabrics like linen have loose weaves. While “breathable” fabrics like linen feel nicer on hot days, they let sun through to your skin. Hold your clothing up to the light – if you can see through it, UV rays from the sun can pass through as well.
Synthetic or semi-synthetic fabrics: Fibers like polyester, spandex, rayon and nylon have elastic threads that pull the fibers tightly together, providing more protection than bleached cottons.
Thickness: Thick or dense fabrics, like denim or corduroy, let in less sunlight than lightweight fabrics, like sheer silks or bleached cottons.
Dark colors: Darker colors absorb more UV rays than lighter colors, keeping them from penetrating your skin.
UPF clothing: UPF, or ultraviolet protection factor, is a rating system used for fabrics that are protective against UV rays. A garment with a UPF of 30 lets in 1/30th of the UV rays, while a thin white cotton shirt probably has a UPF of about 5 – not enough to protect you from a sunburn if you’re out in the sun long enough. UPF clothing doesn’t have to be thick or dark to give you protection. To boost regular clothing’s ability to protect your skin from UV damage, you can use a laundry additive such as Rit Sun Guard. This additive does not work well on synthetic fibers, and cannot change a fabric’s thickness or weave.
Long sleeves and pants, and thick dark fabrics, might be the last things you want to wear when the heat is in the triple digits. The CDC recommends lightweight, light-colored clothing to reduce risk of heat stroke, especially during heatwaves.
“We run across a few of these contradicting recommendations in sun protection,” admits Quale. To reconcile these conflicting recommendations, see last week’s post: Our No. 1 tip for reducing skin cancer risk is to avoid the sun. Protecting yourself from UV rays and minimizing time spent outdoors can reduce your risk for skin cancer as well as heat stroke and other heat-associated illnesses.
If you have to be out in the sun, however, you still can find ways to cover up.
“It’s probably best to invest in a shirt or some clothing that has the ultraviolet protection built into the fabric – UPF of 30 or higher,” Quale recommends. “They actually design many items with venting. It’s an engineering marvel. You don’t need a closet full of UPF clothing, you just need that one long-sleeve, high-collar shirt to wear when you know you’re going to be out for a long period of time. It doesn’t have to be a dark color or a thick fabric.” Lightweight, light-colored UPF clothing can be paired with pants and a hat made of UPF fabric to keep you cool and protected.
Your sartorial decisions should go beyond fabrics and hues. Large-frame sunglasses that block at least 99 percent of UVA and UVB rays can protect the delicate skin around your eyes. Sunglasses should be labeled for UV protection – those labeled “UV absorption up to 400 nm” or “Meets ANSI UV Requirements” will protect you from at least 99 percent of UV rays.
UV rays can penetrate car windows, making sunglasses and sunscreen an important component of any road trip – or just a short errand. In the United States, where the left side of a driver’s body has more exposure to sunlight, skin cancers are more likely on the left side of the body. Windshields have some UV protection, but it’s not adequate to protect you from UVA rays, notes Quale.
The UA Skin Cancer Institute recommends UV-protective tint on your car’s side and rear windows to block up to 99.9 percent of UV radiation. Many states regulate car window tinting. In Arizona, there are window tinting requirements (the front side windows must allow more than 33 percent of light to enter; the back and rear windows can be tinted to your heart’s content), and you can apply for a medical exemption.
Top Five Strategy No. 1: Avoid the Sun
The No. 1 tip for avoiding skin cancer is to avoid the thing that most often causes skin cancer – the sun. More specifically, the sun’s UV rays are what burn our skin and give us skin cancer, not to mention these rays
hasten aging by causing wrinkles, sagging and liver spots. Here on Earth, there are two types of UV rays we need to worry about: UVA and UVB (UVC rays can’t penetrate our atmosphere). According to the American Cancer Society, both types of UV rays cause long-term damage and can lead to skin cancer.
UVA radiation is just outside the spectrum of visible light, with wavelengths too short for humans to see, but long enough to reach deep into the layers of human skin, where it causes tanning but also does damage. UVA rays can penetrate glass, many fabrics and some sunscreens and is prevalent throughout the year. UVA rays are omnipresent during daylight hours – even when it is cloudy – pointing to the importance of protecting your skin from dawn to dusk.
UVB radiation has even shorter wavelengths and damages the top layers of our skin causing redness or sunburn. Luckily, it can’t pass through most fabrics or glass. Although they can cause damage year-round, UVB rays tend to be more intense during the summer months and weaker during wintertime. In the northern hemisphere, the most intense window is from April to October. The “peak hours” for UVB exposure are between 10 a.m. and 4 p.m., corresponding to the more direct angle at which the sun’s rays are hitting the earth. Try to get your errands done in the early morning and in the evening, spending the middle of your day indoors – preferably with air conditioning
Cloudy days can be cooler, but do not be lulled into a false sense of security: 70 to 80 percent of UV radiation can pass through thin clouds, making sunburn possible. When you are outside, seek shade. If you do not want to plant yourself under an awning or tree, you can achieve some protection by carrying portable shade with you in the form of an umbrella or parasol – to shield yourself from sun when walking.
“Umbrellas are a great way to achieve some personal shade,” says Quale. You can look for umbrellas treated with a UV coating; otherwise, look for dark colors if you have access only to regular umbrellas.
Unfortunately, umbrellas, trees and other forms of shade cannot protect you from reflected UV rays. “People should be aware that the sun can still reach the skin and cause damage, even under an umbrella,” Quale says. Umbrellas do not match sunscreen in terms of sun protection and cannot be your only strategy, as UV rays can be reflected off of water, glass, concrete, sand and snow – meaning that exposure to these reflective surfaces can increase your UV exposure. According to the Environmental Protection Agency, white sand and other bright surfaces can effectively double your UV exposure.
Compared to Phoenix, Tucsonans are perched at a relatively high altitude (2,950 feet vs. 1,160 feet), which means we have less protective atmosphere between the sun and our skin. Our southern location also means we are closer to the equator – and UV intensity increases with proximity to the equator. Together, our high altitude and low latitude mean we are more vulnerable to UV rays. Plus, our warm climate invites us to enjoy outdoor activities, often wearing clothes that expose more skin, like tank tops, shorts and sandals.
In addition to avoiding the sun, you should also avoid tanning beds. Indoor tanning is not safer than exposure to sunlight, and just one session with a tanning bed can increase one’s melanoma risk by 20 percent. There is a myth that a “base tan” provides protection by helping to avoid sunburn, but a base tan is equal to wearing sunscreen with a sun protection factor (SPF) of 3 or 4. Sunless tanning options are available, such as bronzing or spray-on products; remember you’ll still need to wear sunscreen outdoors, as the darker color won’t protect you from UV rays.
Your skin health is important regardless of the season. Stay tuned throughout the month for more strategies on reducing your skin cancer risk every day of the year. To request an appointment with a dermatologist, please call the UA Cancer Center at 520-694-2873 or request an appointment online here.
Strategy #1 Image source: CDC Public Health Image Library, 14198, CDC/Amanda Mills
Strategy #2 Image source: SOHO NASA Image and Video Library, PIA03149 ESA
Strategy #3 Image source: CDC Public Health Image Library, 14062, CDC/Amanda Mills