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Sensible Sun Exposure

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Faculty of Medical, Clinical and Veterinary Sciences

Skin Problems

Human Skin | Dry Skin | Psoriasis | Eczema | Greasy Skin | Dandruff | Acne | Rosacea | Seborrheic Dermatitis | Skin Cancer | Non-melanoma Skin Cancer | Melanoma | Hereditary Skin Cancer | Sensible sun exposure

Sunshine presents human beings with something of a dilemma. On the one hand the sun is a good thing - it's warm, it's bright, it makes you feel good. Going outside when the sun is shining is generally preferable to going out in the rain or snow. Perhaps more importantly, the action of sunlight on skin provides the body with its main source of vitamin D, which is essential for healthy bones. Sunlight has also been shown to have important psychological effects, with a form of depression known as Seasonal Affective Disorder being linked to shorter days and lack of sunlight in winter (in the Northern Hemisphere, anyway).

Unfortunately, there is a downside to sunlight: skin cancer. The major types of skin cancer, particularly melanoma and basal cell carcinoma, are almost certainly linked to increased sun exposure. Over the past few decades, the 'importance' of having a fashionable suntan, coupled with the deterioration of the ozone layer, has meant that the incidence of skin cancer has risen dramatically. Overexposure to the sun can also have minor effects, such as increased wrinkling of the skin and other signs of ageing.

Being Sensible

So how do you find a balance between the two faces of the sun? Obviously, staying out of the sun altogether is not an option for most people, so it is fortunate that there are a number of steps you can take to minimise your exposure to excessive sunlight and thereby reduce the risk of skin cancer.

Don't Sunbathe

This sounds a little draconian, but it is good advice, particularly for people with pale or sensitive skin. Being outside and enjoying the sun is one thing. Coating yourself in cooking oil and lying on a beach or lawn for the express purpose of getting a tan is another thing entirely. Don't do it! If a tan is absolutely essential, think about getting one out of a bottle, but bear in mind that, although 'fake' tans make your skin look darker, they do not provide any extra protection against sunlight.

Stay Out of the Strongest Sunlight

The sun's rays are strongest between 10 am and 3 pm. In hot climates, it is usually best to stay indoors between these times1. If you must go out, try to stay in the shade and use a sunscreen with a high protection factor.

Use Sunscreen

When you do go out in the sun, use sunscreen. Sunscreens are classified according to their sun protection factor (SPF), which indicates the time that a particular sunscreen protects you from burning. The length of time that a sunscreen will protect you is equal to the SPF number multiplied by the length of time you could stay in the sun with no protection. So, if your skin would normally burn2 after 10 minutes in the sun, using a sunscreen of SPF 15 means that you can, in theory, stay out for (10 x 15 =) 150 minutes. Note that applying two sunscreens will not provide any additional protection. SPF 10 along with SPF 15 gives SPF 15, not SPF 25. Sunscreen should be applied around 15 minutes before going into the sun, and reapplied every two hours. If you go swimming, use a waterproof sunscreen or reapply sunscreen as soon as you come out of the water.

Most sun protection guidelines recommend SPF 15 for general use. If you are planning on spending a long time in the sun, have very fair skin or are at increased risk of skin cancer for other reasons, sunscreens of SPF 30 are recommended - this is the highest possible factor, as set by the US Food and Drug Administration, and is considered total occlusion. You may find products within the next two years before the grandfather clause takes effect that claim higher, but they are not. SPF 30 is tops, period.

It should be noted that some sunblocks can hinder the body's ability to get rid of excess heat. Most dermatologists now recommend that moisturisers be free of mineral oil for that very reason. It is preferable that skin moisturisers be non-comedogenic (non-pore-blocking) to encourage heat transfer and avoid internal heat build up, as well as preventing blemishes and nasty clogged pores.

The better sunblocks use micro-fine zinc oxide to block ultra-violet radiation, and aloe and other natural, non-oily moisturisers to prevent the skin from drying out.

Some final notes... buying an expensive, branded sunscreen is not necessary, as research has shown that cheaper sunscreens are just as effective. Also, bear in mind that sunscreen loses its effectiveness over time, so sunscreen that has been sitting in the bathroom cabinet for five years will not be as effective as a newly-bought bottle.

Wear Protective Clothing

This doesn't just mean fashionable sunglasses and a silly hat (although these should be considered essential). Sunglasses should be certified as providing protection against ultraviolet light. Hats should have a wide brim to shade the face and back of the neck as much as possible. Wearing long-sleeved shirts and long trousers can also help to protect against overexposure to the sun. Darker clothes may offer better protection than lighter colours, but will also make you feel hotter and more inclined to take them off. If your clothing gets wet you should try to change it - wet clothes lose around one-third of their protective ability. More recently, specially designed clothing with an SPF of 15 or 30 has become available. If you plan to spend time in the sun, it may be worth investing in some. Remember that, no matter how protective the clothing, it will not cover your entire body, so use plenty of sunscreen as well.

And If You Insist on Getting a Tan?

No matter what time of year you arrive, the sun of the tropics will burn unshielded skin in less than 20 minutes. Your best bet is to start out with the highest sun protection you can find.

Limit exposure to no more than a total of one hour on the first day. Believe it or not, this includes time spent going from car to building, lobby to pool and shop to shop. It adds up quickly, and sun exposure is cumulative every minute you are out. Remember that riding in an open car is the same as lying by a pool, except you're probably getting wind damage as well.

You will notice that, even with SPF 30 protection, some reddening of the skin will occur. This will brown down within 24 hours, and your tan will begin. Once the skin begins to protect itself with melanin, you can gradually lower the SPF factor of your protection and get on with the tan.

Above all, moisturise, moisturise, moisturise. Inside and out. Drink plenty of non-alcoholic beverages, and mist or apply more moisturiser to your skin as often as possible.

No matter how hard you work on a tan, the skin will slough off the dead skin cells within 72 hours of your last exposure. While it may be worth it to lord a tan over your mates at the pub, it won't last long enough to justify the deep cell damage and susceptibility to melanomas and other cancers that tropical sun exposure causes.

You will find that people who live in tropical locales avoid the sun. They may tell you that they work all the time and don't go to the beach, but the truth is they know better. They just don't want skin that looks like a leather saddle by the age of 35.

Children and the Sun

Sun damage is cumulative, and the effects of damage that occurs in childhood may only be seen much later in life. Children's skin is particularly sensitive to the sun, and special care should be taken. Babies should be kept out of direct sunlight at all times, as their skin is too sensitive even for sunscreen. Once children are a little older, all the measures described above apply. Children should also be taught good sun-exposure habits, so that putting sunscreen on before venturing outside is as natural as putting on a coat when it rains.

Have Fun!

By being sensible, it is possible to enjoy all the benefits of sunshine without putting yourself at risk. So wait until 3pm, get your SPF 30 sunscreen, your approved sunglasses and your silly hat on, and get out there...

Please Note: h2g2 is not a definitive medical resource. If you have any health concerns you must always seek advice from your local GP. You can also visit NHS Direct or BBC Health Conditions.

1Particularly in the tropics. Don't even think about getting a tan - you will burn.2Important: this is not necessarily the same thing as turning red. Skin burning and damage may occur several hours before signs of redness become visible.

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