A new study has revealed that inhalers used to treat asthma and COPD may have emitted over 20 lakh tonnes of emissions in the US — equivalent to the yearly emissions of about 530,000 petrol-powered cars on the road.

The research team, including scientists from the University of California, Los Angeles, found that metered-dose inhalers — those containing hydrofluoroalkane (HFA) propellants and releasing aerosols — were the most harmful to the environment, responsible for a staggering 98 per cent of emissions over the 10-year period.