The lockdown response to COVID-19 has caused an unprecedented reduction in global economic activity. This study examines whether this reduced tropospheric and ground-level air pollution, and the potential impact of such reductions to premature death and pediatric asthma cases. Findings illustrate the potential health benefits gained from reducing ‘business as usual’ air pollutant emissions from economic activities.

The authors examined satellite data and a network of >10,000 air quality stations from 27 countries. After accounting for the effects of meteorological variability, they found remarkable declines in ground-level nitrogen dioxide, ozone, and fine particulate matter during the first two weeks of lockdown in 27 countries.

Using empirical exposure-response functions, the authors also estimate that there were approximately 7,400 premature deaths and 6,600 pediatric asthma cases avoided during two weeks post-lockdown.

Assuming that the lockdown-induced deviations in pollutant concentrations are maintained for the duration of 2020, they estimate 0.78 (0.09 to 1.5) million premature deaths and 1.6 (0.8 to 2) million pediatric asthma cases could be avoided globally.