Probably many of you have visited the beach or the pool for a swim amid the hot summer weather — and many of you could not avoid the sun
It is important to take protective measures against ultraviolet (UV) light, which is responsible for causing skin damage in the form of sunburn.
Ultraviolet radiation are invisible electromagnetic waves that are harmful to our skin. They are further sub-categorised into UVA, UVB and UVC.
UVA is a wave of a longer length that could darken the skin and thus yield a suntan. It could reach the dermis, speed up skin aging and wrinkle forming. In addition, some research reports suggest that UVA might contribute to skin cancer.
UVB plays a key role in the development of skin cancer. It causes skin aging and reddening. Serious sunburn by UVB could lead to blisters.
As for UVC, all of it is blocked and reflected away by the atmosphere and so it does not do much harm to people.
The seriousness of sunburn would depend on one’s skin colour, ultraviolet light intensity and duration of sunlight exposure. People of a darker skin complexion have more melanin in their skin that could protect them from getting sunburn.
UV light intensity could be interpreted by the UV index. The Hong Kong Observatory indicates the effect of solar ultraviolet radiation on human skin. The higher the UV index, the greater would be the potential for damage to the skin.
Different outdoor environments would also affect ultraviolet light absorption. For instance, one would receive an additional 15 percent radiation at the beach as UV light is reflected by sand.
While UV light comes 40 percent weaker in water half-meter deep, the surface of the pool could increase light reflection. That’s why sunscreen has to be applied even during swimming.
Sufferers of mild sunburn would have red, sore and painful skin. Blisters and peeling skin could also happen. Serious sunburn would cause warmth and pain in the skin lasting more than 48 hours and the body temperature could be up to 38.5 degrees Celsius. They might vomit or even become unconscious.
For treating mild sunburn, patients could apply moisturising cream on the affected skin to ease the pain and burning sensation. Painkillers and anti-itch pills could be taken if necessary.
People with damaged skin should avoid compression and rubbing. Do not burst blisters as this creates wounds and might lead to bacterial infection.
Those who have symptoms such as fever, sudden coldness, severe skin sore or blisters on 20 percent of the skin should see a doctor at once.
Prevention is better than cure and sunburn could be avoided by taking sunscreen measures. Avoid sunbathing between 11 a.m. and 3 p.m. as this period usually comes with the most extreme UV light. Staying in the shade could help reduce UV radiation by half.
Wear sunblock of suitable sun protection factor (SPF) rating 30 minutes before going outdoors and re-apply it every two hours. Re-application is required after swimming or heavy sweating.
The SPF rating system applies to UVB rays only. A product with an SPF of 15, for example, would allow you to stay in the sun 15 times longer than you could without any protection.
People should also choose sun-protecting products with suitable protection grade of UVA (PA) such as PA+, PA++ or PA+++. The more the plus signs, the higher the protection would be.
For clothing, choose dark, loose but high-density clothes to help block UV light. And it is good to wear wide-brim hat and UV protection sunglasses for comprehensive protection.
This article appeared in the Hong Kong Economic Journal on June 22
Translation by John Chui
[Chinese version 中文版]
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