@pravda1 Experts, however, are sceptical of its success. “In a city like Delhi, where pollution levels are high, weather is dynamic and sources of pollution multiple, investing in such devices is not feasible. Nowhere in the world have we seen any data published to establish that this technology improves air quality,” Anumita Roychowdhury, executive director (research and advocacy). “The same money must be spent on reducing emissions. We need real action to cut down on real emissions.”