Throwing ‘shade’ on UV levels

During this scorching and arid season, many people are preoccupied with temperature forecasts and the possibility of rainfall, but health professionals say there is another metric that should be monitored as standard practice – the Ultraviolet Radiation Index (UVI).

Solely focusing on temperatures may lead some to overlook the importance of taking measures to reduce their exposure to UV radiation, which is naturally emitted by the sun’s rays, they said.

While exposure to UV stimulates the human skin to produce Vitamin D, we should watch out for the adverse effects caused by overexposure, these health experts added.

Although Vitamin D is essential for enhancing calcium levels, promoting immunity development, and facilitating blood cell formation, caution should be exercised in dealing with the current hot weather in Malaysia, they stressed.

On its website, the Malaysian Meteorological Department (MetMalaysia) said that due to Malaysia’s proximity to the equator, the UV radiation level here is higher compared with other regions. 

Universiti Kebangsaan Malaysia public health expert Prof Dr Mohd Hasni Ja’afar said there were three types of UV radiation and each could either benefit or pose harm to human skin.

“UV radiation consists of UVA, UVB and UVC. The brightness of daylight that we see is UVA, and it gives the benefit of vitamin D production in our skin … to facilitate calcium (for bone and teeth) absorption in our gastrointestinal tract.

“UVB promotes the production of vitamin D, but it also poses the danger of skin cancer if (people are) exposed too much, while UVC is never able to reach Earth’s surface as it is reflected into outer space,” he added.

Exposure to UVB radiation at mild levels, according to Prof Mohd Hasni, could result in sunburn and eye cataracts.

“Further, it’s able to damage skin DNA and can lead to skin cancers and squamous cell carcinoma,” he said.

Despite Malaysia’s current UVI being within the “healthy” range of 0 to 2, recently recorded temperatures have been notably high, ranging from 35°C to 37°C.

The current heatwave in Malaysia has also resulted in over 15 cases of heat-related illnesses, such as heat stroke and heat exhaustion, according to recent reports, with three more cases reported yesterday in Johor.

According to health expert Dr NKS Tharmaseelan, maintaining moderate exposure is crucial for preventing heat-related illnesses, emphasising the need for understanding both the benefits and risks associated with UV radiation.

“Vitamin D is also called the sunshine vitamin. During normal exposure to sunlight, 7-dehydrocholesterol in the skin absorbs UV radiation and is then converted and isomerised by the body into Vitamin D3.

“Importantly, Vitamin D increases calcium and phosphorous absorption which is essential for skeletal and bone development, and maintenance of the immune system.

“However, overexposure to the sun may result in sunstroke,” said Dr Tharmaseelan.

UV radiation serves as a leading contributor to premature ageing and skin damage, with consistent overexposure posing a risk of skin cancers.

“The immune defence system can also be compromised and suppressed by overexposure, leading to the development of a range of immunosuppressed diseases from skin disease to endocrine disorders and infections,” added Dr Tharmaseelan.

Public health physician Dr Rozita Hod recommended that the public take necessary precautions to safeguard themselves, such as seeking shelter in shaded areas.

She added that UV rays are strongest between 10 am and 4 pm, which would be the best time for the public to stay indoors.

“When going out, people can generously apply sunscreen to cover all exposed skin. They must apply the sunscreen lotion 15 minutes before going outside.

“Sunscreen should have a Sun Protection Factor (SPF) of at least 15 and provide broad-spectrum protection from both UVA and UVB rays. Reapply every two hours, and after swimming or sweating.

“The public can wear protective clothing, such as a long-sleeved shirt (white or light colours), pants, a wide-brimmed hat, and sunglasses, when possible. The sunglasses, glasses, or contact lenses ideally should have 100% UV protection,” added Dr Rozita.

As of yesterday, the UVI stayed within a healthy range, with Johor, Klang Valley, Kelantan, and Sarawak registering UVI 1, while Penang recorded UVI 2.

However, Singapore’s UVI levels were notably higher, ranging from between six and eight, despite Johor, its neighbour, displaying a healthy reading.

Arfa Yunus

The star

Asia News Network