A study assesses the health impact of 2020 landfills in three European cities

The containment measures enacted in March 2020 as a consequence of the COVID-19 pandemic led to decreases in the levels of air pollution, noise and physical activity in cities that had never been seen before. The consequences of these changes for people's health varied depending on the stringency of containment measures in each location and the local context, providing valuable insights into how emergency measures can affect population health.

What lessons can be drawn from this for future urban planning and emergency preparedness policies? A study published in Environmental Pollution and led by the Barcelona Institute for Global Health (ISGlobal), a centre supported by the "la Caixa" Foundation, has sought to answer these questions.

In order to establish comparisons, the research team selected three European cities with different degrees of containment measures: Barcelona, where strict containment was decreed; Stockholm, where the measures were much more lax and ultimately subject to individual responsibility and "common sense"; and, finally, Vienna, which had intermediate measures.

For each of the three cities, they collected or estimated data on air pollution, noise and physical activity from three different points in time: before the pandemic, during the strictest confinement and in the post-pandemic deconfinement period. In a first step, the team calculated differences between pre-pandemic and pandemic levels of the environmental exposures and health behaviours mentioned. In a second step, these differences were compared with data from health systems and translated into how many annual diagnoses of heart attacks, strokes, depression and anxiety could have been avoided or additionally produced in each city if changes in air pollution, noise, physical activity and visits to green spaces had been prolonged for one year.

The first finding of the study corroborated that the degree of stringency of the enacted containment measures was directly related to the magnitude of the decreases in exposures and behaviours studied. Thus, the city with the most stringent containment, Barcelona, was also the city with the largest decreases in pre-pandemic levels of air pollution, noise, physical activity and visits to green spaces. Specifically, during the first containment, nitrogen dioxide (NO2) concentrations fell by 50% on average, daily noise levels were reduced by 5 decibels (dB A) and physical activity was reduced by 95%.

During the same period, in Vienna, NO2 pollution fell by 22%, daily average noise levels were reduced by only 1 dB(A), while physical activity decreased by 76%.

For Stockholm, NO2 levels fell by 9%, daily average noise levels were reduced by 2 dB(A) and physical activity fell by 42%.

After quantifying the variations in each city compared to the pre-pandemic stage, the team calculated the impact of each of these changes on health. To do this, they drew on evidence from previous studies that established relationships between each of the exposures and behaviours studied and various cardiovascular diseases and mental disorders. Finally, in order to reflect the true magnitude of the changes studied in the long term, a data model was used to simulate the impact that the containment measures would have had if extended over a full year.

The analysis of the data set showed that physical activity is the factor with the greatest impact on health of all the factors studied. Thus, a hypothetical extension of strict confinement in Barcelona for a full year would have resulted in a 10% increase in strokes and heart attacks and respective increases of 8% and 12% in diagnoses of depression and anxiety, as a consequence of the general decrease in physical activity.

Reduced physical activity in Vienna over a full year, in turn, could have led to a 5% increase in the annual incidence of stroke and heart attack, as well as increases of 4% and 7% in diagnoses of depression and anxiety, respectively.

Even in Stockholm, the city with the smallest decline in physical activity levels, there would have been negative health effects if the situation had lasted for a year. The model estimated increases of 3% in the respective incidences of stroke and myocardial infarction, 2% in depression diagnoses and 3% in anxiety cases.

The positive reading of the data comes from the decreases in air and noise pollution. It is estimated that if the reduction in NO2 concentrations recorded during the first confinement had been sustained for a full year, 5% of myocardial infarctions, 6% of strokes and 11% of depression diagnoses could have been prevented in the city of Barcelona. In Vienna, the estimated decreases would be 1% for strokes and heart attacks and 2% for depression. In Stockholm, only one effect would be observed and it would be positive: the prevention of 1% of depression diagnoses.

The long-term impact of improvements in noise levels in Barcelona is estimated to have prevented 4% of myocardial infarctions per year, 7% of strokes and 4% of diagnosed depression. In Vienna, the incidence of myocardial infarction, stroke and depression could have been reduced by 1%. Finally, for Stockholm, a 2% reduction in diagnosed heart attacks and depression and a 4% reduction in stroke cases is estimated

"Despite the differences observed in the three cities, there is a repeating pattern: the health benefits of improved air quality and noise would not outweigh the profoundly negative effects of the drop in physical activity levels," summarises Sarah Koch, ISGlobal researcher and first author of the study.

"In terms of urban health, the subsequent confinements and deconfinements gave us the opportunity to generate valuable evidence and to understand how such emergency strategies can have wider impacts on population health. The results of our study show the benefits that could be obtained by implementing urban planning policies that significantly reduce air pollution and noise while encouraging physical activity and contact with green spaces", concludes Mark Nieuwenhuijsen, director of ISGlobal's Air Pollution and the Urban Environment programme and final author of the study

The study used a tool called UTHOPIA to make an assessment of the health risks associated with each exposure and behaviour studied in the pre-pandemic stage and compare it to the acute confinement and deconfinement scenarios. Data on the burden of cardiovascular disease and mental disorders for each city were obtained from public sources.

Sarah Koch, Sasha Khomenko, Marta Cirach, Mònica Ubalde-Lopez, Sacha Baclet, Carolyn Daher, Laura Hidalgo, Mare Lõhmus, Debora Rizzuto, Romain Rumpler, Yusak Susilo, Siddharth Venkataraman, Sandra Wegener, Gregory A. Wellenius, James Woodcock, Mark Nieuwenhuijsen Impacts of changes in environmental exposures and health behaviours due to COVID-19 pandemic on cardiovascular and mental health: A comparison of Barcelona, Vienna, and Stockholm. Environmental Pollution, March 2022. https://doi.org/10.1016/j.envpol.2022.119124

The Barcelona Institute for Global Health (ISGlobal) is the result of an innovative alliance between the "la Caixa" Foundation and academic and governmental institutions to contribute to the efforts of the international community to address health challenges in a globalised world. ISGlobal consolidates a node of excellence based on research and medical care that originates in the hospital (Hospital Clínic and Parc de Salut MAR) and academic (University of Barcelona and Pompeu Fabra University) spheres. Its working model is based on the generation of scientific knowledge through Research Programmes and Groups, and its translation through the areas of Training and Analysis and Global Development. ISGlobal is accredited as a "Severo Ochoa Centre of Excellence" and is a member of the CERCA system of the Generalitat de Catalunya.