Radiation: Protecting against skin cancer

UV damage is mostly avoidable. The rise in the incidence of skin cancers over the past decades is strongly related to occupational and recreational UV exposure. Overexposure to UV radiation is recognized as the underlying cause for harmful effects on the skin, eye, and the immune system. In some cultures, a tan may be cosmetically desirable and has established itself as a symbol of attractiveness and good health. But there is nothing healthy about a tan. It results from your skin trying to prevent further damage. With proper protection, four out of five cases of skin cancer could be prevented. And adopting simple precautions can make all the difference.

There are many physical and psychological benefits of outdoor activities. These need to be balanced with protecting the skin from the known adverse effects of UV radiation. Proper sun protection measures are outlined below.

Limit time in the midday sun

The sun's UV rays are the strongest two hours before to two hours after solar noon. To the extent possible, limit UV exposure during these hours, particularly during the spring and summer months. You can safely be outdoors in the early morning and late afternoon hours with a much-reduced risk of getting burnt.

Watch for the UV Index

The UV Index (UVI) is a measure of the level of UV radiation. The values of the index range from zero upward - the higher the UVI, the greater the potential for damage to the skin and eye, and the less time it takes for harm to occur. This important resource helps you plan your outdoor activities in ways that prevent overexposure to UV radiation. While you should always take precautions against overexposure, take special care to adopt UV radiation safety practices when the UV Index is 3 or above. UV index values for your region or particular location may be found, for example, on the websites of weather services, and on weather apps or on the SunSmart Global UV App, which also displays sun protection times.

Use shade wisely

Seek shade when UV radiation is the most intense. Keep in mind that shade structures such as trees, umbrellas or canopies do not offer complete UV protection. Don't forget that you are still exposed to UV from scattered radiation and reflections, especially in the snow, or in areas with bright surfaces like water surfaces, sandy beaches, or white buildings.

Wear protective gear

The best UV protection when outdoors is achieved with the use of clothing. A hat with a wide brim offers UV protection for the eyes, ears, face, and the back of the neck. Tightly woven clothes protect the skin, and wraparound style sunglasses that provide 100% UV-A and UV-B protection greatly reduce eye damage from sun exposure. 

Use sunscreen

Use broad-spectrum sunscreen on skin areas that cannot be covered by clothes. Sun protection is best achieved by seeking shade and wearing clothes rather than applying sunscreens. Sunscreens should not be used for extending time spent in the sun: while they can delay the onset of sunburn, they cannot completely block UV radiation. It is recommended to apply a broad-spectrum sunscreen (UV-A and UV-B protection) of at least SPF 30 liberally (3 to 4 heaped tablespoons for the entire adult body). Re-apply every two hours, in particular after sweating, swimming, playing, or exercising outdoors.

Avoid sunbeds

Sunbeds are designed to emit strong levels of UV radiation. There is a clear association between sunbed use and skin cancer. The beneficial effects of sunbed use, such as generation of vitamin D, are outweighed by the adverse effects. Therefore, sunbeds are best avoided entirely. Several countries have implemented legislation to ban or restrict the use of sunbeds.

Time of year

You should generally be careful between spring and early autumn when the sun's rays are most intense. In the tropics and near the equator, year-round protection from UV radiation may be necessary depending on your skin type.

Time of day

Little UV radiation reaches the Earth during early morning or late afternoon hours. But UV levels can be very high during midday time, i.e. 2 hours before to 2 hours after solar noon.

Vacation time

When on vacation in sunny locations, there can be a serious risk of suddenly being exposed to intense UV radiation. For fair-skinned people in particular, such intermittent exposure is a serious risk factor for skin cancer. It is therefore important to be aware of your own UV sensitivity and to protect yourself from UV radiation.

Reflective surfaces

Surfaces can reflect UV radiation and thus intensify the UV radiation to levels above the daily peak UV index value. Snow, for example can reflect 90% of UV radiation while white facades around 20% of UV radiation. Make sure you protect yourself against UV especially when you go skiing, do water sports or spend extended time on a light-coloured beach. 

Sunscreens offer a way of protecting your skin against harmful effects of UV radiation. However, they cannot completely block UV radiation and should be used in combination with other methods such as sun avoidance and clothing. Remember that the aim of applying sunscreen is not to prolong your stay in the sun.

Sunscreens may contain physical or chemical UV radiation filters. While physical UV filters reflect or scatter the UV rays, chemical UV filters act by absorbing the UV radiation. Today's broad spectrum sunscreens filter UV radiation in the UV-A and the UV-B range. The sun protection factor (SPF) specifies the degree of protection against UVB radiation, not UVA radiation. 

Always use a sunscreen that filters out both UVA and UVB and has an SPF of 30 or higher. To achieve good protection, apply the sunscreen thickly and evenly to all exposed parts of your body 20 to 30 minutes before going outside. Pay particular attention to the most exposed parts such as ears, nose, forehead, and neck. You should re-apply the sunscreen every two hours, and especially after bathing and sweating, as sunscreen is wiped off when drying off. The use of a lip balm containing a sunscreen also protects against recurrent lip eruptions of cold sores.

A number of studies have shown that most people do not apply sufficient amounts of sunscreen and therefore do not achieve the specified SPF.  Approximately 35 ml of sunscreen must be applied to the total body surface of an adult to result in the quoted SPF. It is better to apply too much sunscreen than too little.

Sunscreens are not to be confused with after-sun creams which moisturize or soothe dry and sunburnt skin. After-sun lotions neither protect against UV radiation nor repair UV-induced DNA damage.

Clothing provides the best barrier from the sun. Clothing together with a wide-brimmed hat, shoes and sunglasses are the essentials for your summer sun protection kit. Several factors determine the effectiveness of clothing in protecting against UV radiation. Several factors determine the effectiveness of fabrics in protecting against UV radiation, such as the clothing design, fabric structure (knitted or woven yarn), pore size, fiber thickness and composition of the material. Other factors include the fabric’s colour, finishing treatment (e.g. impregnation or use of UV-resistant substances) as well as whether the garment is wet or dry.

• Less UV passes through tightly woven or knitted fabrics.
• Darker colours usually block more UV radiation.
• Garments that are over-stretched, wet or worn out may lose some of their UV protection properties.
• Synthetic fibers (lycra, polyester) generally provide better protection than cotton, particularly when the garment is wet.

Some UV textiles are available with a garment labeling called the Ultraviolet Protection Factor (UPF). The UPF is a measure of the protection provided by an item of clothing against UV radiation (both UVB and UVA). It is the equivalent of the sun protection factor or SPF for sunscreens. The higher the UPF value, the less UV radiation reaches the skin and the better the protection against sunburn and other harmful effects. For example, a UPF 50 fabric blocks 98% of the sun's rays and allows 2% (1/50th) to penetrate the fabric. Such textiles may be useful for those who practice outdoor spots and/or jobs. 

Just as with the skin, UV exposure to the eye is cumulative over a lifetime and may cause irreversible damage. Sunglasses help your vision and protect your eyes. They make you feel more comfortable under bright light conditions as they reduce glare and improve contrast. You cannot tell how much UV radiation a pair of sunglasses block based on the color of the lenses, their darkness, or their price. UV transmission through sunglasses varies considerably. However, most sunglasses on sale filter a large percentage of UV radiation.

For sunglasses to be fully protective against UV radiation, the lenses should absorb UV-A and UV-B radiation until 400 nanometers wavelength. You can recognize sunglasses with such protective lenses on the sign “UV400”. Also ask your optician for the filtering specifications, especially for sunglasses with visual acuity. Wraparound-style sunglasses offer enhanced protection of the eyes, especially for outdoor workers and athletes.

UV radiation levels vary substantially with time and place. Therefore, you should check the UV index sat your location, which indicates the level of UV radiation. The increased risk of UV damage to the skin and eye during a vacation in a sunny location is often underestimated. Beyond the discomfort of sunburn, tourists are also at particular risk of long-term health effects on the eye and skin, especially skin ageing and skin cancer. 

Yes, children are more sensitive to UV radiation than adults, and therefore require special protection. Sunburns at any age, but especially in childhood, increase the risk of developing melanoma, the most serious skin cancer. Also, children have more time to develop diseases with long latency such as cancer, more years of life to be lost and more suffering to be endured because of impaired health.

Children themselves are usually not aware of the harmful effects of UV – it is their parents' or guardians' responsibility to protect their child from short-term and long-term damage.

• Always keep babies less than 12 months in the shade.
• Never let infants or young children sleep in the sun.
• Encourage your children to play in the shade.
• Make sure your children wear protective clothing, including a hat and sunglasses, when they go outdoors.
• Get your children used to wearing sunscreen.
• Apply sunscreen lotion with high protection generously and at least every two hours! Pay particular attention to the most exposed body parts, the face, neck, shoulders, back, knees and tops of feet.
• Do not allow children or teenagers to use sunbeds.