Air Quality Picking Up In Countries Locked Down Over Coronavirus

Air quality is improving in countries under coronavirus quarantines, experts say, but it is far too early to speak of long-term change.Images by the US space agency NASA are clear, in February the concentration of nitrogen dioxide (NO2) fell dramatically in Wuhan, China, the epicentre of the COVID-19 pandemic, passing from an indicator that was red/orange to blue.NO2 is mainly produced by vehicles, industrial sites and thermal power stations.