Even as some residents and businesses in the city turn to expensive High-Efficiency Particulate Air (HEPA) purifiers, medical experts note that it is a waste of money for healthy individuals and that the N-95 masks costing a few hundred rupees do a better job. HEPA filters capture particles in the air as small as 0.3 microns, including pollutants and bacteria.

Dr Vikas Oswal, a renowned pulmonologist, said air purification systems are only recommended for patients with high-risk respiratory conditions. “Healthy people do not require air purifiers. In closed spaces, even ACs or fans might do the job, but if there are serious patients at home, then these purifiers can help,” he said. However, even as these air purifying systems may help patients suffering from conditions like asthma, there is no escaping pollutants once out of the house.