The reductions, in particular nitrogen dioxide (NO2), are due to the reduction in traffic and other activities, especially in cities with containment measures, says the EEA in a statement.

The EEA says it has received many questions about the impact of strong measures to halt the spread of the new coronavirus, which causes covid-19, on air quality in Europe.

“The EEA data show an accurate picture of the drop in air pollution, especially due to reduced traffic in cities. However, addressing long-term air quality problems requires ambitious policies and continued investments. As such, the current crisis and its multiple impacts on our society go against what we seek to achieve, which is a fair and well-worked transition to a resilient and sustainable society”, replies the executive director, Hans Bruyninckx.

In Lisbon, according to the data, the average levels of NO2, a pollutant emitted especially by road transport, fell 40 percent from one week to the next. Compared to the same period last year, the reduction was 51 percent.

Reductions are taking place in many European cities. According to the document, in Milan (Italy) the average concentrations of NO2 in the last month decreased by 24 percent in relation to the previous month, a value similar to that of Rome. In Barcelona (Spain) the NO2 drop was 40 percent from one week to the next and in Madrid the drop was 56 percent.

The EEA recalls in the document that air pollution harms health and can lead to respiratory and cardiovascular diseases. And says it is not yet clear whether continued exposure to air pollution can worsen the condition of people affected with covid-19.

Air pollution data was collected through a network of more than 4,000 local pollution measurement stations across Europe.