A new study finds that heatwaves raise surface ozone levels across India, adding to cardiac deaths. It links about 830 extra deaths from heart disease and COPD to the 2024 heatwaves.
The peer-reviewed study published in npj Clean Air on June 12 reports that surface ozone reaches 85-110 micrograms per cubic metre in northern India during heatwaves and exceeds the WHO guideline of 70 micrograms per cubic metre nationwide.
Authors Parambat Sangeetha and Jayanarayanan Kuttippurath analysed data from 2004 to 2024. They estimated 26,500 ozone-linked deaths from ischaemic heart disease and COPD during the 2024 heatwave days, with the heatwave adding roughly 830 extra deaths.
The Western Himalayas saw the steepest ozone rise, exceeding the WHO guideline by 115 percent in 2024. The authors stated that coupled heat-ozone extremes are intensifying and require urgent integrated climate-air quality policy action.