Several districts in Kerala have been reporting high ultraviolet index (UVI), the level of UV radiation from the sun on a scale of one to 11, in the past few days, raising concerns about its possible health impacts.
According to the Kerala State Disaster Management Authority (KSDMA), Munnar in Idukki recorded a UVI of 12 and Konni in Pathanamthitta 11 on March 17. Kottarakkara in Kollam and Changanassery in Kottayam reported 10, Ponnani in Malappuram recorded nine, and Thrithala in Palakkad eight. Beypore in Kozhikode, Kalamassery in Ernakulam, Vilappilsala in Thiruvananthapuram, and Chengannur in Alappuzha reported seven each. Mananthavady in Wayanad and Ollur in Thrissur recorded six each. The high UVI is recorded between 10 a.m. and 3 p.m.
The World Health Organization says that a purple alert needs to be issued if the radiation level is at 11 and above (extreme), and there are increased health risks. If it is between eight and 10 (very high), a red alert is issued calling for extra precautions. If the UV index is between six and seven (high), an orange alert is issued and precautions will have to be taken.
T. Jayakrishnan, public health expert, says that high exposure to UV rays may lead to gradual loss of skin elasticity, premature ageing, wrinkling, and skin pigmentation. It can damage the skin, eye, and the body’s defence mechanism. On the skin, it can lead to sun tan, sun burn, redness, swelling, blisters, allergic reactions, and itching. Photo-toxic reactions may happen in people who use certain cosmetic products, soaps, and herbal remedies. On a long-term basis, there is a possibility of skin cancer and melanoma, a type of tumour. UV ray exposure may also suppress the immunity, affecting the body’s ability to defend certain diseases.
There are two types of UV rays: UVA rays and UVB rays. The former penetrates deeper into the skin and even to the blood vessels. Sun burn is mainly caused by the UVB rays. They also stimulate melanin pigmentation, resulting in sun tan marks, which could exist forever.
Dr. Jayakrishnan points out that a small amount of UV rays could reach the retina of the eyes too. This penetration could be severe in the case of children. Prolonged exposure could damage the retina at a later stage. “Photokeratitis, a painful condition of the eye, and pterygium, a non-cancerous growth that occurs on the conjuctiva, are some of the other possibilities,” he says.
Idukki, Palakkad, and Malappuram had experienced high UVI of 11 on March 14,. Kollam recorded 10, and Pathanamthitta, Kottayam, Alappuzha, Ernakulam, Thrissur and Kozhikode had a UV index of nine. According to a study published in the journal Environmental Monitoring and Assessment, covering the period between 2004 and 2022, more than 79% of the UV measurements in Kerala were in the very high and extreme categories. High values were noticed during the south west monsoon and the summer. Thrissur, Palakkad, parts of Ernakulam, Idukki, parts of Kollam, and Thiruvananthapuram were found to be more vulnerable in terms of high UV exposure. A cyclical increasing and decreasing pattern was shown, with peaks in March, April and September and lower indices in June, July and December.
Dr. Jayakrishnan says that sunscreen lotions may not be necessary for people living in tropical countries like India. Dark-skinned people genetically have enough melanin to protect them from the sun. Wearing sunglasses will help. “Those working in sand banks, waterbodies are more at risk due to reflections. Fishermen and those engaged in the construction of buildings and roads need to be careful. Hats and UV protected umbrella can be used,” he adds.
Published – March 18, 2025 08:43 pm IST