Air quality has received much attention since the onset of the Covid-19 pandemic, and changes in behaviour and economic activity over the past two months. This briefing looks at what we would expect to see, the observed changes in air quality and the implications for clean air policy and human health.
Levels of nitrogen dioxide (NO2) have fallen significantly in most urban regions. The data shows that that future policies to reduce vehicle emissions in individual cities, whether through lowered traffic levels or switches to cleaner vehicles, will reduce NO2 levels.
Changes in particulate matter (PM) levels are less directly apparent in the data we have at the moment and will require longer term analyses to quantify. This reflects the wider range of PM sources and the importance of regional, as well as local, emissions. Future reductions in PM will require coordinated, regional approaches across a range of sectors.
Living in areas with poor air quality leads to chronic and acute health conditions. It is plausible that these increase susceptibility to Covid-19; however, the magnitude of this effect is not yet known.