Damage from adverse exposure to UV rays, such as pigmentation, skin cancers and wrinkles, can never be fully repaired, according to Dr Suretha Kannenberg, a consultant in the division of dermatology at Stellenbosch University’s faculty of medicine and health sciences. 

“The vast majority of skin damage occurs during childhood and teenage years, then accumulates with the years,” she adds. Dr Bianca Tod, a dermatologist and senior lecturer in the division, agrees that “many of these effects stem from sun exposure in our youth” and that early “sun protection is like saving for your retirement”. 

UV rays explained

Ultraviolet (UV) radiation is part of the solar radiation (sunlight) spectrum, which falls within the electromagnetic spectrum, according to the US Centers for Disease Control and Prevention.

UV rays are further divided into three subgroups: UV-A, UV-B and UV-C, with UV-A being the most dangerous. On the UV index and associated UV risk level scale, from 0-2 (low risk) to 11+(extremely high risk), the vast majority of South Africa is categorised as being at an extreme risk for UV exposure. 

“South Africa is a country with high UV levels that are frequently high enough to cause damage to our skin and eyes,” says Tod. “The Northern Cape tends to have the highest UV index levels, although very high levels are observed in all provinces, depending on prevailing conditions.”

These conditions extend to a location’s proximity towards the equator (the closer to the equator, the higher the UV levels), the season (higher levels in summer), weather, time of day, altitude and changes in the ozone layer, Tod adds. 

Tanning a sign of skin damage

“Excessive UV light exposure is associated with damage to the skin. This damage can be divided into acute (early) and chronic (delayed) effects,” says Tod. Acute effects include sunburn and heat stroke, while chronic effects include an increased risk of skin cancer, skin ageing and uneven pigmentation. 

“Sunburn is an indication of damage to the DNA of skin cells. This triggers inflammation: redness, pain and generally feeling unwell,” says Kannenberg. 

Even though people with darker skin are less likely to develop sunburn (visible redness or pinkness of the skin) than those with lighter skin, they might note dryness, irritation or darkening of the skin, explains Tod. 

“Some individuals will have a tanning response to sun exposure,” says Kannenberg. “This is [the] body’s way of protecting the sensitive DNA inside skin cells [from] sun exposure.” 

She says a tanning response indicates that the skin is being damaged. As this damage accumulates and the immune system weakens with age, the remaining sun damage may lead to skin cancer. 

“Sun-related skin cancers are much more common in people with light skin colours,” says Tod. However, there is a “common misconception that people with darker skin colours do not get skin cancer”, when in fact people with medium skin colours “develop sun-related skin cancers reasonably often”. 

According to a 2021 study evaluating the susceptibility of different skin colours to cancers, researchers found that darker colours possess an inherent sun protection factor (SPF) of 13.4, while light colours have an SPF of 3.3. “Of course, this will vary widely as there is no such large variation in skin colour,” says Tod. She says that the risk factors for different skin colours and types remain largely unresearched, and that the research gaps are only starting to be addressed. 

Pigmentation and ageing

“UV exposure also leads to many of the visible signs of ageing and uneven pigmentation,” says Tod. “Again, the signs of ageing from sun exposure tend to be more pronounced in people with light skin colours, but they do occur in all skin types. Uneven pigmentation (blotchy, dark marks) from sun exposure can be particularly prominent in people with darker skin colours.”

Kannenberg adds that pigmentation is also part of the ageing process and that darker skin colours “are much more sensitive to develop pigmentation such as melasma after sun exposure”. Furthermore, this melasma “is much more severe and lasts much longer than lighter skin types”. She also warns that sunbeds are strongly linked to ageing, and that the concentrated UV-A radiation in such treatments is “intensely involved in the development of melanoma”. 

Additional effects

Tod says UV exposure can also cause eye damage, which may lead to complications such as cataracts, while Kannenberg explains that UV rays can also “exacerbate some underlying skin disorders such as eczema and lupus erythematosus”. 

Besides UV exposure, researchers are starting to understand that visible light and infrared radiation also exert important effects on the skin, according to Tod. These areas of the solar spectrum can influence the development of uneven pigmentation. Subsequently, it is noticed that some new sunscreens indicate protection against visible light.  

Even though the effects of sunburn, tanning and acute sunstroke are reversible, many other effects aren’t. “Skin cancer can usually be treated but may be deadly in some cases. Treatment can cause unsightly scars, and it can be expensive and time consuming,” Tod explains. “Sun-related ageing can be improved, but never completely reversed, and again, this treatment is expensive and time consuming.”

Kannenberg says pigmentation, or melasma, is extremely difficult to treat. And even though there are “many strategies to treat uneven pigmentation”, it often still comes back.  

Protocol for UV protection

It is best to avoid being in the sun between 10am and 4pm, when UV levels are highest, according to Tod. During outdoor activities, plan to provide shade and avoid being in the sun in the middle of the day, she adds. 

“Sunscreen can only do what it promises to do if applied in adequate amounts every two hours, after swimming and even more frequently with sweating,” says Kannenberg. 

Read in Daily Maverick: “How to protect your skin from the summer sun”

People with light skin colours should apply a sunscreen of SPF 50 or more, while SPF 30 should suffice for dark skin colours. In the case of existing pigmentation, she recommends SPF 50+. 

“The sunscreen should also contain UV-A protection and the newer ones will also contain high-energy visible light protection. If it contains an antioxidant, even better,” notes Kannenberg. “A tinted sunscreen will give you more protection from high-energy visible light. Also look out for the Cansa seal of approval and that it says ‘non-comedogenic’.”

“Many people think of sunscreen as the beginning and end of sun protection, but it is only one component of our sun-protection strategy,” says Tod. 

“Wear clothing and accessories that protect you from the sun: long sleeves, long pants and high collars, clothing that either has a UPF rating or that is densely woven, broad-brimmed hats (not caps), and good-quality sunglasses.” 

Wearing sun-protective swimming costumes that are not tight fitting is also advised for protection against UV rays, according to Kannenberg. “As soon as the garment is stretched, it does not give you the protection it promises.”

Finally, Kannenberg warns against drinking alcohol in the sun, simply because “one tends to spend more time as planned in the sun then”. DM/ML

• Damages from adverse exposure to UV rays, such as pigmentation, skin cancers and wrinkles, can never be fully repaired.
• On the UV index and associated UV risk level scale from 0-2 (low risk) to 11+(extremely high risk), the vast majority of South Africa is categorised as being at an extreme risk for UV exposure.
• Tanning is the body’s way of protecting sensitive DNA inside skin cells to sun exposure and is actually a sign of skin damage.
• According to a 2021 study, darker skin colours possess an inherent sun protection factor (SPF) of 13.4, while light skin colours have an SPF of 3.3.
• UV exposure leads to many of the visible signs of ageing and uneven pigmentation.
• Even though the effects of sunburn, tanning and acute sunstroke are reversible, many other effects aren’t.
• Applying sunscreen is only one component of the sun-protection strategy.