Short-term effects of lockdown measures on air quality

ID’s recommended reads – 27/07/2020 – Wanda Van Hemelrijck & Lucía Rodríguez Loureiro

Lockdown measures, although unevenly implemented throughout the globe, had an evident impact on transportation and consequent air pollution levels. Assessing the impact on air quality was, however, difficult due to other factors, such as meteorological conditions, that contribute to overall air pollution levels, and the short study period available, insufficient to detect and quantify differences with pre-confinement levels. Now that confinement measures are gradually being reduced and air pollutant concentrations are raising again in the atmosphere, researchers are starting to detect significant changes in several air pollutants during the lockdown period.
The big question now is whether these short-term changes in air quality will affect our health and well-being, and how. Has it had an impact on the mortality related to COVID-19 or other respiratory infections? Will we see an effect on people with other underlying conditions, such as chronic obstructive pulmonary disease (COPD), asthma or hypertension?

This week’s recommended reads: Evidence of decreasing nitrogen dioxide levels all over the world and particulate matter in China, a literature review assessing the impact of air quality on the severity of respiratory infections, and results from an English survey among patients with lung conditions suggesting reduced respiratory symptoms during the lockdown.

1) Impact of Coronavirus Outbreak on NO2 Pollution Assessed Using TROPOMI and OMI Observations
Bauwens, M., Compernolle, S., Stavrakou, T., et al. (2020)

A study from atmospheric scientists at the Royal Belgian Institute for Space Aeronomy using satellite observations over China, South Korea, Western Europe and the United States and demonstrating unprecedent decreases in NO2 levels during the period from January-April 2020. In China, these decreases reached up to 70% in some cities, while in Europe the reductions were around 30%.

2) The short-term impacts of COVID-19 lockdown on urban air pollution in China
He, G., Pan, Y., Tanaka, T. (2020)

The journal Nature Sustainability recently published an analysis on concentrations of particulate matter with an aerodynamic diameter smaller than 2.5µm (PM2.5) in China, using a comparison between cities under lockdown and a control group of cities that weren’t. The PM2.5 was reduced by approximately 14µg/m3 in lockdown-cities, and the effects were larger in colder and more industrialized cities. However, particulate matter levels were still above the World Health Organization recommendations.

3) Effects of air pollutants on the transmission and severity of respiratory viral infections
Domingo, J., Rovira, J. (2020)

Despite an evident relationship between high concentrations of air pollutants and the risk of respiratory viral infections and the intensity of symptoms, there is scarce evidence available in the context of the COVID-19 pandemic.

4) Nearly 2 million people with lung conditions notice improved symptoms as a result of drop in air pollution
British Lung Foundation (BLF). (2020)

A survey conducted with over 14,000 individuals living with lung conditions in the UK revealed that more than half of the respondents experienced a considerable improvement in their symptoms during lockdown. This includes around 25% of people with asthma, and 1 in 5 parents reporting an improvement in their children’s symptoms.