PREVENTION OF SKIN CANCER:
SUN SAFETY

You can take proactive steps to reduce your risk of skin cancer. Although you can’t modify some of your risks (like your skin color), you can modify other risks by avoiding or limiting your exposure to them. Please see Basal Cell Carcinoma Risk Factors and Squamous Cell Carcinoma Risk Factors for a discussion of the specific risks for each type of skin cancer.

Be Sun Smart

The vast majority of the 5 million-plus skin cancer cases in the United States are caused by ultraviolet (UV) light exposure. Practicing sun safety and avoiding indoor tanning are key steps to reducing the number of cases of skin cancer. We can group tactics to assure sun safety into three types of strategies: practice sun sense, use sunscreens effectively and often; and put on some sun wear. Details about these strategies/tactics are described below.

Practice Sun Sense

Avoid the midday sun

Since the sun’s UV rays are strongest between the hours of 10 am and 4 pm, it’s best to limit your sun exposure during those hours.

Seek shade when appropriate

When outside, seek shade to limit your exposure to the sun.

Don’t try to get tan

A tan means damage has already
occurred. See Fact vs Fiction below.

Fact vs Fiction: If I get a nice base tan, I will be protected from sunburns and sun damage.

FICTION. Many people grew up thinking that while a sunburn causes damage, the development of a gradual base tan not only makes you look healthy, it provides good protection from a sunburn. Now we recognize that tanning itself is evidence of DNA damage. When ultraviolet rays penetrate the skin and reach the melanocytes (the pigment cells that produce melanin), they release melanin to serve as a shield to prevent further damage. So while the body tans as a protective mechanism, it’s not even effective: The extra melanin in tanned skin only provides a sun protective factor (SPF) of 2–4, which doesn’t provide much protection. In addition, every time your skin is damaged, you speed up the aging of your skin. So getting a tan puts you at risk for skin cancer and ages your skin, and that’s not healthy (or attractive) at all!

Use Sunscreens Effectively and Often

Tips for getting the most benefit from sunscreens:

Select a broad-spectrum sunscreen of at least SPF 30 or higher. Broad-spectrum sunscreens protect you against both UVA and UVB. You also need a sufficiently strong sunscreen. For more about Sun Protection Factor (SPF), see Science Sidebar (How do we measure sun protective qualities?)
Limit your time in the sun. Sunscreens are designed to protect you from the sun, not give you license to spend more time in the sun. A sunscreen with an SPF of 30 does not allow you to stay in the sun 30 times longer. Lot of factors affect how long you are protected–the time of day, the intensity of the sun, and your skin type. Bottom line: don’t get a false sense of security from your sunscreen–limit your sun exposure to be safe.
Make sure it’s still good. Sunscreens can go bad. Check the expiration date. If it doesn’t have an expiration date listed, it has a shelf life of three years (less if it’s been exposed to heat/direct sun). Not sure how long you’ve had it? If it changes color from white to yellow, starts to separate, or has a funny consistency, throw it out
Apply it generously. Most people only apply a quarter to half of the sunscreen they need. Slather it on. One ounce (about a shot glass full) is needed to cover your whole body
Cover the forgotten/tricky spots. Do a thorough job. Apply sunscreen to your scalp, the top of your ears, the back of your neck, the top of your feet, and even the underside of your chin (which can burn from reflected sun). If you can’t apply sunscreen to some of these locations, cover them with clothing
Give it time to be absorbed. Because chemical sunscreens need time to be absorbed in order for them to work, apply sunscreen 15 minutes before going into the sun. If you are using a mineral sunscreen, it will work right away. See The Scoop on Sunscreens Table below
Reapply often. If you are outdoors, reapply every two hours or after swimming/sweating
Wear it every day! Even on an overcast day, the sun can damage your skin. So use sunscreen every day, regardless of the weather and what you have planned for the day. The sun may damage your skin in just five minutes
Wear lip balm. Don’t forget your lips—they are not immune to skin cancer. Apply a lip balm with SPF 30 or greater and reapply it regularly

Science Sidebar

How do we measure sun protective qualities?

Sun Protection Factor measures how much protection from the sun’s UVB rays that a sunscreen provides. It is calculated as the “dose” of UV radiation required to cause skin reddening with the sunscreen applied vs the UV dose that causes skin reddening without sunscreen. SPF does not measure the increased time you can spend in the sun without burning. Sunscreens with an SPF of at least 30 will block at least 97% of the sun’s UVB rays. Higher numbers block slightly more, but none block 100% of the sun’s UVB rays. Use a sunscreen with at least an SPF of 30 that is broad spectrum to protect against both UVA and UVB rays.

UPF is the sun protective measure for clothing. It stands for Ultraviolet Protection Factor. A UPF rating of 50 means that only 2% (1/50th) of UV rays can penetrate the fabric.

The Scoop on Sunscreens

Types of Sunscreens	Description	UV Light They Protect Against
Physical Blockers (aka inorganic/mineral sunscreens)	Reflect or scatter UV light like a shield Are not absorbed Work immediately upon application Contain zinc oxide and/or titanium dioxide	Both UVA and UVB (broad spectrum)
Chemical Absorbers (aka organic sunscreens)	Absorb UV light like a sponge Transform UV light into a nonharmful wavelength (infrared) Take time to absorb into the skin Contain a variety of chemical agents such as oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate	Depends: UVA, UVB, or both (broad spectrum)

Put on Some Sun Wear

Wear broad-brimmed hats

Choose hats with broad brims (at least three inches all around) if possible, since they cover more of your face/neck than baseball caps. If you wear a baseball cap, be sure to put sunscreen on your ears and neck.

Cover up with clothing

Darker colored clothing is more protective than lighter colored, and dry clothing is more protective than wet clothing. And clothing that has a high Ultraviolet Protection Factor (UPF) is best. See the Science Sidebar (How do we measure sun protective qualities?) for detail.

Wear UV-blocking sunglasses

The bigger the sunglasses, the better the eye protection. Ideally the sunglasses should be labeled “UV absorption up to 400 nm” or “Meets ANSI UV requirements,” meaning that they block 99% to 100% of UVA and UVB rays. UV light can damage your eye and lead to ocular melanoma. In addition, it can contribute to the formation of cataracts, which can affect your vision over time.

Kids’ Corner—Helping protect children from the sun

Several strategies can be employed to help children stay sun safe. Parents, you need to educate your kids and advocate for them.

Why is this important?

Sun Damage and Sunburns During Childhood Increase Skin Cancer Risk

Sun damage builds up over time, so even tanning every once in a while can have unintended consequences over the course of your lifetime. We experience nearly half of our exposure to UV before age 20! Cumulative sun exposure is linked to development of basal cell carcinoma, squamous cell skin cancer, and melanoma. Sunburns—especially blistering sunburns occurring before age 18—are also linked to the development of melanoma.

You May Have to Overcome Barriers to Keep Your Children Safe

Sunscreen is labeled as an over-the-counter drug by the FDA, and many schools require certain authorizations for students to be provided or allowed to use such medications. Know the regulations in your state and the policies of your child’s school. See https://www.ncsl.org/research/health/states-promote-sun-safety-for-children.aspx Make sure your child has access to sunscreens and is using them during outdoor time at school and other activities.

Educate them!

Some important steps you can take to protect children include educating them to:

Use sunscreen (broad spectrum, at least SPF 30)
Cover up by wearing a hat, sunglasses, and clothes that cover their arms and legs, if possible
Seek shade when the sun’s rays are strongest, between 10 am and 4 pm
Never use indoor tanning equipment

Protecting Babies:

Babies represent a special case because of the sensitivity/vulnerability of their skin. Here are some tips to keep them safe:

Keep them in the shade. If there’s no natural shade, create your own with an umbrella, pop-up tent, or the canopy of the stroller.

Dress them in sun-protective clothing. Make sure your baby wears a hat that provides sufficient shade at all times and clothing that covers and protects sensitive skin. Also consider a wide-brimmed hat and sunglasses.

If at all possible, don’t use sunscreen for children younger than six months of age. It is best to use other means of sun protection. Consult your pediatrician before using any sunscreen on your baby. If you need to use sunscreen, those that contain titanium dioxide or zinc oxide are less likely to irritate the baby’s skin.

Along with other types of sun protection, you should use a sunscreen once children are older than six months of age. You might want to consider a mineral sunscreen for the reasons listed in Science Sidebar: Are there safety concerns with sunscreens?

Science Sidebar: Are there safety concerns with sunscreens?

For you? A recent follow-up study in the Journal of the American Medical Association (JAMA) assessed whether you absorb some of the chemicals in sunscreens beyond your skin. In 48 healthy individuals, the study looked at blood concentrations of key chemicals in various formulations of sunscreens following a single application on day one and multiple applications through day four, and the study subjects were followed for a 21-day period. The study found that the active ingredients were absorbed, resulting in plasma concentrations of sunscreen chemicals that were higher than the FDA threshold for requiring additional safety studies.

What does this mean? We don’t know yet. We don’t know if the absorption of these chemicals causes harm. We have to wait for additional tests from the FDA. But experts suggest that if these results concern you, consider using a mineral-based sunscreen, as these are not absorbed and have been established as safe.

For the environment? Recently, studies have raised concern about certain chemicals in sunscreens—oxybenzone and octinoxate—that have been implicated in damaging coral reefs. While more research is needed (some members of the scientific community question the connection between these ingredients and coral reef bleaching), both the state of Hawaii and Key West, Florida have banned these two ingredients starting in 2021. The bottom line is that there are other types of both chemical and mineral sunscreens available. Despite these findings, sunscreens should remain an essential part of protection against skin cancer.

Understanding Ultraviolet Radiation

Ultraviolet (UV) radiation is energy produced by the sun and by artificial sources such as tanning beds. Ultraviolet means light that is not in the visible spectrum that we normally see. Think “beyond” (ultra) violet light, which has the shortest wavelength of visible light. There are three types of UV radiation that we are concerned with:

UVC is the most dangerous type of UV radiation. Fortunately, most of the sun’s UVC is absorbed by the atmosphere and doesn’t reach the earth’s surface. However, UVC is emitted during arc welding, along with other types of UV radiation. Therefore, welders need to protect themselves with face shields, protective clothing, and eye protection.

UVB is the second most potent type of UV radiation. It penetrates the top layer of the skin and is the primary cause of sunburns (remember “B” for burns) and delayed tanning. UVB is the main cause of basal cell and squamous cell carcinoma as well as melanoma.

UVA is the least potent type of UV radiation but most abundant, constituting 95% of the UV light that reaches us. It causes the immediate tanning effect. Because it penetrates deeply, it can contribute to skin aging, leathering, and wrinkling (think “A” for aging). UVA penetrates clouds and car windows. It makes UVB-induced damage worse and increases your risk for developing skin cancers.

Your level of UV exposure is increased by certain factors:

Midday (the sun is highest in the sky)
Higher elevations (air is thinner and cloud cover is thinner)
Locations near the equator and the tropics (because the sun is highest in the sky)
Sunny days (but it is still an issue on cloudy days)
Ozone holes (over the North and South poles)
Longer exposure time

PREVENTION OF SKIN CANCER: SUN SAFETY