Short-term and long-term health impacts of air pollution reductions from COVID-19 lockdowns in China and Europe: a modelling study

Abstract

Background: Exposure to poor air quality leads to increased premature mortality from cardiovascular and respiratory diseases. Among the far-reaching implications of the ongoing COVID-19 pandemic, a substantial improvement in air quality was observed worldwide after the lockdowns imposed by many countries. We aimed to assess the implications of different lockdown measures on air pollution levels in Europe and China, as well as the short-term and long-term health impact.

Methods: For this modelling study, observations of fine particulate matter (PM_2·5) concentrations from more than 2500 stations in Europe and China during 2016-20 were integrated with chemical transport model simulations to reconstruct PM_2·5 fields at high spatiotemporal resolution. The health benefits, expressed as short-term and long-term avoided mortality from PM_2·5 exposure associated with the interventions imposed to control the COVID-19 pandemic, were quantified on the basis of the latest epidemiological studies. To explore the long-term variability in air quality and associated premature mortality, we built different scenarios of economic recovery (immediate or gradual resumption of activities, a second outbreak in autumn, and permanent lockdown for the whole of 2020).

Findings: The lockdown interventions led to a reduction in population-weighted PM_2·5 of 14·5 μg m^-3 across China (-29·7%) and 2·2 μg m^-3 across Europe (-17·1%), with unprecedented reductions of 40 μg m^-3 in bimonthly mean PM_2·5 in the areas most affected by COVID-19 in China. In the short term, an estimated 24 200 (95% CI 22 380-26 010) premature deaths were averted throughout China between Feb 1 and March 31, and an estimated 2190 (1960-2420) deaths were averted in Europe between Feb 21 and May 17. We also estimated a positive number of long-term avoided premature fatalities due to reduced PM_2·5 concentrations, ranging from 76 400 (95% CI 62 600-86 900) to 287 000 (233 700-328 300) for China, and from 13 600 (11 900-15 300) to 29 500 (25 800-33 300) for Europe, depending on the future scenarios of economic recovery adopted.

Interpretation: These results indicate that lockdown interventions led to substantial reductions in PM_2·5 concentrations in China and Europe. We estimated that tens of thousands of premature deaths from air pollution were avoided, although with significant differences observed in Europe and China. Our findings suggest that considerable improvements in air quality are achievable in both China and Europe when stringent emission control policies are adopted.

Funding: None.

Figure 1

Effect of lockdown on surface PM_2·5 concentrations Difference between mean PM_2·5 concentrations (μg m⁻³) during the lockdown period (Feb 1 to March 31, for China, and Feb 21 to May 17, for Europe) and the average in the same period in 2016–19 for China (A), and Europe (B), computed by combining numerical model simulations and ground-based observations (represented by dots).

Figure 2

Short-term health impacts of improved air quality and COVID-19 during the lockdown period in (A) China and (B) Europe in 2020 Avoided premature deaths due to reduced PM_2·5 concentrations are indicated by green bars, additional premature deaths due to increased PM_2·5 concentrations are indicated by dark purple bars, and COVID-19 deaths are indicated by light purple bars. Differences in premature deaths are calculated on the basis of the difference between daily PM_2·5 in 2020 (blue line with triangles) and the daily mean PM_2·5 concentration over 2016–19 (red line with circles). Error bars indicate SD from the mean.

Figure 3

Long-term health impacts Avoided premature deaths per 100 000 inhabitants due to changes in air quality (variations in PM_2·5 concentrations) under four different scenarios for China and Europe: an immediate resumption of anthropogenic activities, a gradual resumption of economic activities, total lockdown in the autumn following a second outbreak, and permanent lockdown until the end of 2020.

Figure 3

Long-term health impacts Avoided premature deaths per 100 000 inhabitants due to changes in air quality (variations in PM_2·5 concentrations) under four different scenarios for China and Europe: an immediate resumption of anthropogenic activities, a gradual resumption of economic activities, total lockdown in the autumn following a second outbreak, and permanent lockdown until the end of 2020.