Most skin cancers are caused by too much exposure to the sun - specifically solar ultraviolet (UV) radiation or rays. These can damage the cells in the skin and cause them to mutate. This causes skin cancer. Melanoma is the most fatal kind of skin cancer.
The risk of skin cancer depends on a few things including family history, lifestyle (such as spending a lot of time outdoors), a personal history of skin cancer and skin pigment. Other factors include skin that burns easily, having a large number of moles and older age.
A big factor in skin cancer risk is skin pigment. This is called melanin. Melanin is like a natural sunscreen that protects us from the sun's harmful UV rays. Exposure to the sun is the most important risk factor for skin cancer. People who are deeply pigmented (dark skin) have more melanin than people with light skin and are less likely to get skin cancer from too much exposure to the sun.
People with deeply pigmented skin can also get skin cancer. But there is no evidence to suggest that this occurs because of sunburn or exposure to the sun. For people with deeply pigmented skin, skin cancer is more likely to occur on the palms of the hands and soles of the feet, and on places of previous injury or wounds.
For their part, people with lightly pigmented skin are most at risk of skin cancer caused by the sun's UV rays. Those who spend time outdoors, either for long times or during the middle of the day when the sun is strongest, risk getting excessive sun exposure and sunburn.
Many countries in Africa experience high levels of solar ultraviolet radiation almost all year round. People at risk should protect themselves from the sun to reduce their chances of getting skin cancer. Anyone wanting to protect themselves from sun damage, such as wrinkles which do not have a health risk but may be disfiguring, and pigmentation or colouring of the skin, as well as people on certain medications and people with skin conditions, should also wear sun protection.
Practising sun safety
Protection from the sun is important in all seasons of the year, not just summer when the sun feels hot. Solar UV rays can still be harmful in cooler seasons and when the sky is cloudy. Practising sun safety is important all year round.
Solar UV rays can also reflect off surfaces such as water, sand, snow, and cement. It's important to use sun protection at places like the beach and dams to protect yourself from excessive sun exposure.
The simplest ways to protect yourself from getting too much sun are by wearing clothing that covers as much as your body as possible (arms, body, and legs), and wearing sunglasses and a hat. These physical barriers help to stop most of the solar UV rays from reaching your skin. It can depend on the type and colour of the fabric - light-coloured clothing offers less sun protection than darker colours, which absorb more solar UV radiation.
If you can, try to limit the amount of time you spend outdoors between 10h00 and 16h00 when the solar UV rays are at their strongest. If you must be outside, use sun protection.
Sunscreen is the next line of protection for places that cannot be easily or fully covered with clothing, including your face, ears, and the tops of the feet. Try to use a sunscreen with the highest sun protection factor (SPF) that you can afford. SPF 50 is considered to offer good sun protection, but whatever sunscreen you can afford to buy and apply is better than not using any at all. The most important thing to remember with any sunscreen is to apply the product according to the instructions on the bottle and re-apply it often, especially after swimming or sweating.
Avoiding direct sunlight and use shade as much as possible. Tree shade, sunshades or sails, gazebos, awnings and umbrellas offer shade. Be careful when there are spots of sun coming through between the shade - don't get caught thinking you are safe from the sun when you are not. If you raise your hand and make a shadow, there are probably some solar UV rays shining on your hand.
Indoor tanning using a tanning bed, sunbed, or sunlamp to darken the skin exposes the skin to high levels of UV rays. Spending time on a sunbed can lead to serious injury through accidents or burns. But more importantly, several studies have found that using a sunbed causes melanoma skin cancer. To reduce your skin cancer risk, do not use sunbeds. A tan does not indicate good skin health.
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A healthy relationship with the sun
Spending time outdoors doing sports, relaxing and having fun is an important part of many people's lifestyles.
Being exposed to some sun can help your body make vitamin D, which helps keep bones, teeth and muscles healthy and also makes you feel good because of a hormone called serotonin. Serotonin can help improve your memory and get a good night's sleep.
Too much sun exposure causes sunburn and increases your risk of skin cancer. It also leads to wrinkles, fine lines and pigmentation as a result of sun damage.
Caradee Yael Wright, Specialist Scientist (Public Health), South African Medical Research Council
