According to a new study, COVID-19 lockdowns across China and Europe have averted tens of thousands of premature deaths related to air pollution
Particulate matter (PM2.5) are tiny airborne particles smaller than 1/10,000 of an inch in diameter and come from various combustion-related sources such as industrial emissions, transportation, wildfires and chemical reactions of pollutants in the atmosphere. Long time exposure can be hazardous to human health and even cause premature death associated with lung cancer, ischemic heart disease, stroke and chronic obstructive pulmonary diseases. According to the World Health Organization, there were 4.2 million premature deaths worldwide due to air pollution, in 2016.
Paola Crippa, assistant professor in the Department of Civil and Environmental Engineering and Earth Sciences at Notre Dame and her team integrated advanced computer simulations with measured PM2.5 concentrations from more than 2,500 sites in Europe and China in between January 1st, 2016 and June 30, 2020 – during which both regions initiated lockdowns as COVID-19 began spreading rapidly.
They discovered that PM2.5 concentrations in China dropped by 29.7% between February – March and dropped by 17.1% in parts of Europe between February – May.
Crippa said: “We look on these lockdowns as the first global experiment of forced low-emission scenarios. This unique, real-world experiment shows us that strong improvements in severely polluted areas are achievable even in the short term if strong measures are implemented.”
The team estimated rates of premature death against four different economic recovery scenarios:
- An immediate resumption to normal activity and subsequent emissions,
- A gradual resumption with a three-month proportional increase of emissions,
- The potential of a second outbreak of COVID-19 between October and December in each region,
- A permanent lockdown for the remainder of 2020 in the case of ineffective control strategies.
From February to March, the study discovered improvements in air quality were widespread across China because of extended lockdown measures and an estimated 24,200 premature deaths associated with PM2.5 were averted throughout China compared to 3,309 reported COVID-19 deaths.
However, the situation in Europe was quite different. While COVID-19 related deaths were far higher in Europe, an estimated 2,190 deaths were still avoided during lockdown when compared to averages between 2016 and 2019.
Crippa concluded: “The most surprising part of this work is related to the impact on human health of the air quality improvements. “It was somewhat unexpected to see that the number of averted fatalities in the long term due to air quality improvements is similar to the COVID-19 related fatalities, at least in China where a small number of COVID-19 casualties were reported. These results underline the severity of air quality issues in some areas of the world and the need for immediate action.
“In China, we saw that lockdowns implied very significant reductions in PM2.5 concentrations, which means that policies targeting industrial and traffic emissions might be very effective in the future. In Europe, those reductions were somewhat smaller but there was still a significant effect, suggesting that other factors might be considered to shape an effective mitigation strategy.
“If interventions of a similar scale to those adopted to address the COVID-19 pandemic were widely and systematically adopted, substantial progress towards solving the most pressing environmental and health crisis of our time could be achieved.”
Co-authors of the study include Paolo Giani, Stefano Castruccio, Wenjing Hu and Don Howard, all at Notre Dame, and Alessandro Anav with the Italian National Agency for New Technologies, Energy and Sustainable Economic Development.