You may have seen the before-and-after-lockdown photos of major cities that appear to show dramatic changes in air quality. In one, the India Gate war memorial in New Delhi is barely visible amid the smog. Then, during lockdown, it’s clearly visible in its red Bharatpur stone grandness.
Getting vehicles off the road may do wonders for smog, but there’s more to air pollution than that. The shift away from vehicles powered by fossil fuels and the improvement of outdoor air quality in urban areas, combined with changes to buildings and lifestyles, means that indoor air pollution will become much more important in the future. And there aren’t many easy answers about how much of a risk this will create – or how to address it.