The sun produces energy in a variety of ways, from the heat we feel on our skin to the more visible and invisible spectra and radiation. Without the sun, life on earth would be impossible but, despite all the benefits we get from the great star at the centre of our solar system, there are also drawbacks.
Sunlight keeps us warm and stops us descending back into the ice age. It nourishes us through the vitamin D we absorb as well as the food it helps us grow. It gives us night and day. Unfortunately, the sun has its negative aspects too. UV light can cause skin cancer in plants and animals; it can do significant damage to our eyesight and it can even cause severe dehydration with too much exposure. It is no surprise then, that being sun savvy is essential to our wellbeing as humans.
It may come as a surprise that something that is 149-million kilometres away can have such a significant impact, but it takes light from the sun only eight minutes to travel that distance! Solar radiation and sunlight make life on earth possible and it is as a result of our own irresponsibility and carelessness that the sun is able to inflict so much damage on the human population. The development of cancers and other excess sun exposure-related illnesses are a testament to this.
The ozone layer is thinning and solar radiation is at the highest it has ever been on record. So, we need to be sun savvy to protect ourselves, otherwise we’re quite literally playing with fire. But what is solar radiation? To put it simply – the sun is basically a massive solar reactor and the energy we receive from the sun comes from these nuclear reactions. Through this solar reaction, solar radiation is produced, in much the same way a nuclear plant produces radiation – but on a much larger scale. This process produces both infrared and UV (ultraviolet) rays. Whilst the ozone does a lot to filter out much of this solar radiation, some of it still enters our atmosphere and poses a threat to our wellbeing.
The harmful side effects of UV rays
Some parts of the world – such as the Western Cape – are exposed to more solar radiation than others and therefore we see higher incidences of melanoma and sun-induced skin cancers in these areas. But why are UV rays so damaging? Sunburn is caused by the disruption of the skin cells through UV radiation. Long-term, this repeated disruption of one’s skin cells can cause cancer cells to form. In fact, without the ozone layer – the sun’s UV rays would turn the earth into a barren desert wasteland.
Ongoing and prolonged exposure to UV radiation can have some very severe side effects from skin damage to eye damage and even damage to the immune system. The occasional and rare over-exposure to the sun will primarily do superficial damage and make you uncomfortable for a few days. But longer term, the continued exposure of the skin to UV rays will cause the degeneration of one’s cells including the skin, fibrous tissue and the blood vessels. The results range from less severe side effects including premature ageing and sun-related skin diseases like photodermatosis and actinic keratosis to the more severe side effects like melanoma and carcinoma (or cancer).
Approximately 66 000 people globally die from melanoma and skin cancers and 130 000 malignant melanomas are found annually. Fortunately, early identification and treatment can be effective in many cases of sun-related skin disease, but fair-skinned populations are more at risk than any other. This does not by any means mean that darker-skinned individuals are not susceptible to skin cancer. In fact, research suggests that, whilst those with darker skins may be less likely to develop skin cancers, they also often only identify these cancers at a much later and more advanced stage, which can be dangerous. The reality is that most skin cancers are treatable if identified early but most of them are also preventable through the right behaviours and attitudes.
In addition to the obvious impact that UV rays have on our skin, there is evidence that suggests that environmental radiation levels can also have an impact on our body’s cells and immunity – this increasing the risks of infectious diseases and potentially reducing the effectiveness of vaccinations. These factors are particularly debilitating in developing countries and can significantly impact their infant, toddler and child populations. Further to this, the proximity of developing countries to the equator line exacerbates the issue, as UV rays are often much stronger in these regions.
Let’s look a little more closely at UV radiation. It is made up of UVA, UVB, and UVC bands. Filtered by the ozone layer, the majority of what reaches the earth’s surface are UVA rays and these rays are primarily responsible for the ageing of our skin. In some cases, they also do damage to our cells and affect our DNA and in others they can cause skin cancer. The trouble with UVA rays is that – unlike UVB rays – ithey do not cause sunburn. This puts us at added risk because we do not even feel the effects of these rays on our skin and they make up 95 per cent of the solar radiation that penetrates our atmosphere. Further to this, UVA rays can easily penetrate glass, which makes protecting our skin just as important indoors as it is outdoors.
According to a study at the NYU School of Medicine, researchers found that UVA radiation damages the DNA in some of our cells (melanocytes) and this has been proven to cause mutations that can lead to melanoma. These melanocytes are the cells in which our melanin is stored and this is what is responsible for darkening our skin. This skin darkening is the body’s response to these cells being in trauma and trying to protect themselves from UV radiation. A further study conducted at the University of Texas M. D. Anderson Cancer Centre found that the risk of developing melanoma (most deadly form of skin cancer) is only in part linked to UVB rays. So, in essence, we need to be concerned with both UVA and UVB rays, because both can cause skin cancer and, combined, the results can be deadly.
Skin cancer in South Africa
When looking at Caucasian populations, South Africa ranks the second highest for incidences of skin cancer in the world, after Australia. The upside is that skin cancer can be prevented by being respectful of the sun, looking after your skin and following the right practices to reduce your risk.
Let us look at the three most common types of skin cancer:
Basal Cell Carcinoma
The most common form; most skin cancers are basal cell cancer. It starts at the top layer of the skin (epidermis) and occurs most frequently in skin that is regularly exposed to sunlight, for example the scalp, ears, nose and shoulders.
Most prevalent in individuals with:
Light skin and light eyes (blue / green);
Blond or red hair;
Freckles and moles;
Family history of skin cancer;
Frequent sun exposure;
Numerous sunburns throughout their lives.
Squamous Cell Carcinoma
Second most common form of skin cancer. Also occurs in the epidermis. Curable in 95 per cent of cases when detected early. Most-commonly found in fair-skinned, middle aged and elderly people. Can also occur on sites where there have been previous injuries like burns, scars, sores etc. Typically linked to long-term sun exposure. Those previously diagnosed with skin cancer are more susceptible to squamous cell carcinoma.
Accounts for one per cent of cancer deaths worldwide and the incidence of melanoma globally is on the rise. It is especially prevalent in Caucasians living in sunny, hot countries like South Africa and Australia. The 2009 figure for the Western Cape was 69 new cases per 100 000 Caucasians – higher than that of Australia. In 1990, this figure was a mere 22.2 new cases per 100 000 Caucasians. It is typically found in individuals with a tendency to sunburn rather than tan and most found on sun-exposed skin on the body. There have also been strong links made between melanoma and breast cancer as well as prostate cancer. Malignant melanoma can also be found in darker skinned individuals and is often harder to identify.
Below is a summary of the incidences of these three most common skin cancers in South Africa as assessed in 2013 according to the National Cancer Registry.
|Type of Skin Cancer||Group||Actual Number||Lifetime Risk||% Total of all Cancers|
|Basal Cell Carcinoma||Male||9 175||1:16||25,53%|
|Squamous Cell Carcinoma||Male||3 929||1:39||10,93%|
There is a definite link between the occurrence of breast cancer and melanoma. A link has recently also been established between certain prostate cancers and melanoma.
How to protect yourself from skin cancer
Check Your Skin Every Three Months
Check every inch of your body and get a friend, family member or partner to help for the areas you cannot check thoroughly. Take photos of moles and areas you want to keep track of to observe changes. If you notice anything unusual – see a doctor or dermatologist immediately.
Know your ABCDEs.
Asymmetry – common moles are round and symmetrical.
Border irregularities – common moles have smooth and even borders.
Colour variations – common moles are brown or black and are a consistent shade.
Diameter – anything larger than six mm is a red flag.
Evolving – take note of changes in shape, colour or border of a mole.
Understand your risk level
Whilst everyone is susceptible to skin cancer, it is far more prevalent in those with fair skin, freckles / moles and red or blonde hair. If you have a family history of skin cancer or spend a lot of time outdoors you are also considered high-risk.
Sun savvy parenting
Much of the sun damage that manifests later in life has already been done before we turn 18. It is critical that we take special care with our children when in the sun. Children should be kept out of the direct sun between 10am and 3pm, and they should always be wearing sunscreen and protective clothing. Babies younger than 12 months should not be exposed to direct sunlight at all.
Know Your Skin Types
The Fitzpatrick Scale outlines different skin types by breaking it down into 6 categories. See below.
|Type||Features of unexposed skin||Tanning and burning||How to Protect It||Risk of Cancer|
|I||Very pale white skin, often with green or blue eyes and fair or red hair||Burns without tanning||Use a broad-spectrum sunscreen with an SPF of at least 30 every day. Avoid sun exposure as much as possible. Wear protective clothing especially a hat and sunglasses.||Very High|
|II||White skin, often with blue eyes||Burns and does not tan easily||Use a broad-spectrum sunscreen with an SPF of at least 30 every day. Limit sun exposure as much as possible. Wear protective clothing including a hat and sunglasses.||High|
|III||Fair skin with brown eyes and brown hair||Burns first then tans||Use a broad-spectrum sunscreen with an SPF of at least 15-20 every day. Keep sun exposure to a minimum. Wear a hat and sunglasses.||Medium|
|IV||Light brown skin, dark eyes, and dark hair||Burns a little and tans easily||Use a broad-spectrum sunscreen with an SPF of at least 15 every day. Do not spend excessive time in the sun. Wear a hat and sunglasses.||Medium|
|V||Brown skin, dark eyes, and dark hair||easily tans to a darker colour and rarely burns||Use a broad-spectrum sunscreen with an SPF of at least 10-15 every day. Minimise sun exposure. Wear a hat and sunglasses.||Medium to Low|
|VI||Dark brown or black skin, dark eyes, and dark hair||Never burns but tans darker||Use a broad-spectrum sunscreen with an SPF of at least 10 every day. Avoid excessive sun exposure. Wear sunglasses.||Low|
Follow Cansa’s Recommendations
1. Avoid direct sunlight between 10am and 3pm.
2. Cover up and wear sun-protective clothing.
3. Always wear sunscreen of at least a factor 20, even in the shade..
4. Protect your eyes and use sunglasses with a protection rating of above UV 400.
5. Check the expiry date of your sunscreen and replace it after 12 months once opened.
6. Do not use sunlamps or tanning beds.
7. Protect your children and do not allow them to get too much sun exposure.
8. Check your skin regularly.