PETALING JAYA: The higher the Solar Ultraviolet Index (UVI) value, the greater the potential for damage to the skin and eye, and the less time it takes for harm to occur, says the Malaysian Meteorological Department (MetMalaysia).
The UVI, which describes the level of solar UV radiation at the Earth’s surface, is set on a scale from zero upwards.
According to the MetMalaysia website, a scale of two and below on the UVI is considered low while three to five is moderate and six to seven is high.
A score of eight to 10 is considered very high, while anything higher than 11 is considered extreme.
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On May 21, the Vietnamese National Centre for Hydro-Meteorological Forecast predicted that levels of UV radiation in major cities across the country are expected to peak between eight and 10.
MetMalaysia said the UVI varies throughout the day and in reporting the UVI, most emphasis is placed on the maximum UV radiation level on a given day.
“For MetMalaysia, the UVI is reported hourly from 11am to 4pm,” its website said.
It added that small amounts of UV radiation are essential for the production of vitamin D in humans but overexposure to it may lead to short- and long-term adverse effects on the skin, eyes and immune system.
“Sunburn (erythema) is the best known acute effect of excessive UV radiation exposure.
“Over the longer term, UV radiation causes inflammatory reactions of the eye and induces degenerative changes in cells of the skin, fibrous tissue and blood vessels, leading to premature skin ageing, skin rashes and scaly skin conditions,” it said.
MetMalaysia added that chronic effects include skin cancer and cataracts.
“Annually, some 12 to 15 million people suffer blindness from cataracts worldwide.
“According to World Health Organisation estimates, up to 20% of these cases may be caused or enhanced by sun exposure, especially in countries close to the equator.
“UV radiation may also suppress the immune system, thereby enhancing the risk of infectious disease and limiting the efficacy of vaccinations,” it said.
MetMalaysia added that it is a popular misconception that only fair-skinned people need to be concerned about overexposure to the sun.
Darker skin has more protective melanin pigment and the incidence of skin cancer is lower in dark-skinned people, it said.
“Skin cancers do occur in this group and unfortunately, they are often detected at a later, more dangerous stage.
“The risk of UV radiation-related health effects on the eye and immune system is independent of skin type,” it added.
