The bristling summer in Kerala is not just about high-temperature warnings anymore. The daily alerts on the UVI (Ultraviolet index) by the Kerala State Disaster Management Authority (KSDMA) give insights into alarming UV levels, guarding people against the dangerous effects of sun exposure. Kerala is probably the only state in the country that now relies on an established system to issue alerts on UV levels. 

KSDMA began preliminary work on the need to assess and monitor UV levels as early as 2019. Isolated incidents of sunburn cases emerged from different parts of the district. Between 2013 and 2022, Kerala reported 11 deaths due to heat/sunstroke. Heat-related events, though not as frequent as extreme rainfall-triggered disasters, flagged ominous signs of climate change. The Government notified Heat Waves, Sun Strokes, and Sunburns as state-specific disasters in March 2019. 

Following this, KSDMA with the support of UNDP decided to establish 14 Ultraviolet radiometers in Kerala so as to ensure continued monitoring of UV levels in the State as such a network or data was not forthcoming from IMD. The system is in the testing phase as on October 2020. Officials with the State Emergency Operations Centre (SEOC) said that they started analysing available data on heat related events and a heat action plan was being readied. "We didn't have a specific model in the country. We relied on our data analysis and finalised the need for instrumentation," said Fahad Marzook, Hazard Analyst – Atmospheric Science, SEOC. 

With no network to disseminate UV levels, the KSDMA with the support of UNDP installed 14 UV radiometers in Kerala to ensure continued monitoring of UV levels. The sensors were calibrated and were installed at selected locations across the state in 14 districts. The testing went on for a year. The crucial need for data collection, streaming, real-time updates and storage for analysis had to be addressed. This was where the KSDMA tied up with the International Centre for Free and Open Source Solutions (ICFOSS). A micro-climate monitoring system was already put in place in Kerala, which provides updates on rainfall, temperature and humidity. KSDMA integrated UV index with this system. 

ICFOSS, a part of LoRa Alliance, a global non-profit agency working on creating compliance for LoRaWAN, used a preexisting network to provide a system that furnishes changing UV levels every 15 minutes. LoRaWAN is a low-power, wide-area networking protocol designed for wireless connection of battery-operated stuff to the Internet. This can be done in regional, national or global networks. 

"The sensors were attached to a 1.5 m high pole. The integration was completed within a year. The system is so designed that it gives updates every 15 minutes. The values collected by the sensor get loaded to a cloud-based storage system, and values are visualized using the software," said Shafeek P M, who is associated with the project. Open access to visualized data guides the public to safeguard themselves from harmful UV effects. 

The UVI was developed through an international effort by the World Health Organization (WHO) in collaboration with the United Nations Environment Programme (UNEP), the World Meteorological Organization (WMO), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the German Federal Office for Radiation Protection. A practical guide on UV index published by the WMO says that while small amounts of UV radiation are beneficial for people and essential in the production of Vitamin D, prolonged exposure to UV radiation results in acute, chronic health effects on the skin, eye and immune system. Skin cancers and cataracts are the two major chronic effects. 

The UV Index is grouped into 5 different categories and each category has a color code. The values 0-2 are classified as Low (green); 3-5 as Moderate (yellow); 6-7 as High (orange); 8-10 as Very High (red); 11+ as Extreme (violet). A month-long monitoring of UV levels in Kerala has produced varied results with some places like Munnar recording levels in the very high category. "This is attributed to the high altitude. These insights are being closely studied. A place which records high temperature need not record high UV levels," said Fahad. With increasing altitude, less atmosphere is available to absorb UV radiation, and UV levels increase by approximately 10 per cent with every 1,000 m in altitude, according to the WHO. 

A study on the spatial and temporal dynamics of daily UVI for 18 years ( 2004-2022) in Kerala by the researcher Ninu Krishnan Modon Valappil, in collaboration with the KSDMA, showed that more than 79% of the measurements fell into the categories of very high and extreme UVI values, which suggested the need to implement appropriate measures to reduce health risks. Higher UVI was observed during the months of March, April, and September. The region also showed higher UVI during the southwest monsoon (SWM) and summer seasons.