Health, air pollution, COVID19: an integrated approach

Lock-down measures in spring in Lombardy saved 20% of premature deaths from COVID19, but pollution exceeded WHO levels one in every four days.

In a new publication in Environmental Research Letters, researchers from the European Institute on Economics (EIEE) and the Environment, Bocconi University and Politecnico di Milano have quantified the health repercussions of the lock-down measures implemented in Lombardy last spring.

The researchers have applied novel machine learning techniques to project what the pollution would have been without lock-down, using data from 83 monitoring stations in the region from the past years to train the model. This has allowed isolating the effect of lock-down restrictions from confounding factors such as weather. Previous work has mostly compared similar periods in the last years, without accounting for the variation in weather patterns.

Francesco Granella, the lead author of the study, explains the results of the analysis. “Harsh containment measures partially reduced PM2.5 and NO2, by 16% and 33% respectively. The lock-down reduced emissions from transportation, and to a lesser degree from industry. Important sources of emissions such as heating and especially the agricultural sector were not reduced. As a result, pollution continued to exceed WHO safeguard one day in four.”

Lara Aleluia Reis, an air pollution expert at EIEE, remarks that “despite the limited impact on pollution, the lockdown saved up to 25 premature deaths in 100.000 people. During the same period, COVID killed about 150 people out of 100.000. That is, improved air quality saved almost 20% of COVID related deaths”.

This highlights the dramatic impacts of air pollution. According to the European Environmental Agency, Italy is one of the EU countries suffering the most from bad air, with 65000 premature deaths estimated each year, and concentrated in Northern Italy. “The analysis”, concluded Prof. Massimo Tavoni, director of the institute leading the study, “highlights the need for an urgent and integrated response to the air pollution crises in Italy. Its devastating health consequences are now more salient than ever”.

A website providing a visualization of the results is available here https://lombardy-lockdown-and-pollution.netlify.app

The research paper is available on Environmental Research Letter: https://iopscience.iop.org/article/10.1088/1748-9326/abd3d2