Are you safe in the sun
Monday 18 July 2016
Sunlight is the main source of ultraviolet radiation (UVR). UVR damages the DNA in our skin and is a major risk factor for most skin cancers. Sunburn, which is ours skins response to this damage, increases our risk of developing melanoma, the most serious form of skin cancer. As well as skin cancer, long term UVR exposure also causes our skin to age more quickly with the development of saggy skin, wrinkles and brown patches, along with precancerous skin changes. UVR also increases our risk of cataracts and other eye problems.
What is Ultraviolet radiation?
Sunlight consists of 2 types of harmful rays that reach the earth, ultraviolet A (UVA) and ultraviolet B (UVB) rays. While UVB (the burning ray) has been considered the main culprit in sunburn and skin cancer, recent research has confirmed that exposure to the deeper penetrating UVA (tanning ray) also carries an increased risk of skin cancer along with premature aging of the skin.
Shade, clothing and sunscreen
So to stay safe in the sun we need to minimize our exposure to ultraviolet radiation. It’s important to think about everything you can do to protect yourself. The best protection is a combination of shade, clothing and sunscreen. In the UK we get most sunshine between May and September. The strongest and most dangerous exposure time is between 11am and 3pm. When abroad, a simple way to find out when the sun’s rays are strongest is to look at your shadow-if it’s shorter than your height, it means the suns UV rays are strong. Remember that cloud cover does not protect us against damage because 30-40% of the UV rays will pass through cloud. Also water, sand, snow and even concrete reflect back ultraviolet light and increase the chances of burning and skin damage. It is important to move into the shade during the hottest part of the day and limit time in the sun at midday. Cover up using clothing, hats, and T shirts. Choose a wide-brimmed or Legionnaires hat. The more skin that is covered by clothing the better protection you are getting. Look for materials with a close weave that blocks out most of the UV rays. Holding fabric up to the light is a good way to see how much light is getting through. Certain fabrics such as cotton will stretch when wet and thereby allow more rays through.
Also don’t forget to protect your eyes. For best eye protection choose sunglasses with lenses that block UVA and UVB rays. (UV400). Choose a wraparound style if possible to protect the delicate skin around the eyes. A tint alone on a pair of spectacles will not block UV rays.
Babies and children need extra protection because their skin is is delicate and easily damaged. Children with fair or red hair and freckles are most at risk. Keep babies under 6 months out of direct sunlight especially around midday. For babies under 6 months shade, sun protective clothing and hats are best.
The first thing about sun protection is that it’s not all about sunscreen. Sunscreens work by blocking and absorbing UV rays. These products don’t afford complete protection against UV and should not be used to extend your time in intense sunlight. No sunscreen, no matter how high the factor can provide 100% protection, which is why we recommend using sunscreen together with shade or clothing to avoid getting too much UV exposure
What is SPF?
Generally the SPF (sun protection factor) indicates the UVB protection, and the star system reflects the UVA protection. SPF describes how long the product will protect your skin from burning if you apply the sunscreen correctly. Very light-skinned people start to burn in 15 minutes, so wearing an SPF 15 if applied properly would prevent sunburn for 225 minutes (15x15mins). SPF 30 will prevent sunburn for 450 minutes. A common misconception however is that higher factor sunscreens offer proportionally higher protection. This is not true. For example an SPF 15 will filter out 93% of UVR whereas SPF 30 will filter out 97% and SPF 50 98%. There is a concern that higher factor sunscreens may lure people into a false sense of security and it has been shown that many people burn more frequently when using a higher factor because they stay out in the sun longer.
Which sunscreen should I buy?
It is important to choose a “broad-spectrum” sunscreen that protects against both UVA and UVB rays. You want something with at least 4 stars of UVA protection and an SPF of at least 15. For fairer skinned people, an SPF of 30 is best and dermatologists would generally recommend this.
The price of your sunscreen isn’t important; it is the protection that it gives. There are many different formulations available. For example, creams are useful for the face and areas of drier skin. Gels are useful for very hairy skin but they do tend to sweat off more readily. Sprays are convenient for children, but it is important to avoid inhaling and getting into the eyes. Sticks are useful for the lips and under the eyes. Waterproof and water- resistant sunscreens are popular, but waterproof sunscreens begin to lose effectiveness after 80 minutes while swimming or sweating, while water-resistant ones allows about 40 minutes. Most sunscreens have a 2-3 year sell by date so discard those that are out of date. Do not store in very hot places as extreme heat can ruin their protective chemicals.
How do I apply sunscreen?
No matter the SPF or star rating, a sunscreen only works if you apply it generously and regularly. We recommend for your face and arms you probably need about 2 teaspoons of sun cream. For your legs and rest of your body you probably need about 2 tablespoons.
Apply before you go out. Don’t rub it in too hard. It needs to form a barrier on your skin so pat it on, smooth it in. It is important to reapply sunscreen during the day if you have been sweating, if you rubbed it off or have been swimming. Remember to put on another layer every few hours and always after swimming and sweating.
Every time you tan you damage your skin. As the damage builds you speed up the aging of your skin and increase your risks for all types of skin cancer. What you don’t see is UV damage to the deeper layers where there is a build up from every tan you have ever had.
There is no such thing as a “safe tan”.
If you or a family member are concerned about sun damage or other skin conditions you may wish to seek advice from Dr Norren Cowley, Consultant Dermatologist.