The goal of this study is to analyze how levels of air pollution changed between countries with their restriction policy of lockdown to cope with the COVID-19 pandemic. The study design compares average changes of CO, NO₂, SO₂, O₃, PM_2.5 and PM₁₀ concentrations based on measurements at ground level in January, February, and March for the years 2019, 2020, 2021, and 2022 (during the COVID-19 pandemic crisis) to average values of a 2015–2018 baseline period (ex-ante COVID-19 pandemic) between 300 cities in 19 countries of five geoeconomic regions. Results reveal that the maximum reduction in air pollutant concentrations is given by: CO (−4367.5%) in France, NO₂ (−150.5%) in China and Australia, SO₂ (−154.1%) in Israel, O₃ (−94.1%) in China, PM_2.5 (−41.4%) in Germany, and PM₁₀ (−157.4%) in Turkey. Findings show that the effects of restriction policies for COVID-19 pandemic on air quality vary significantly between countries, depending on the different geographical, economic, industrial and social characteristics of the countries. These results clarify the critical relationship between control measures for pandemic crises and levels of air pollution in countries that can support best practices of environmental policy for pathways of sustainable development.

The goal of this study is to analyze associations between COVID-19 transmission and meteorological indicators in cities of the Black Sea region of Turkey, located specifically in the dampest area, with excess rainfall and recurring fog. In particular, the working hypothesis is that the widespread transmission of new coronavirus SARS-CoV-2 (leading to the airborne disease COVID-19) in cities can be explained by specific weather conditions, namely high levels of air humidity. Statistical evidence here does not seem, in general, to support the hypothesis that the accelerated transmission of COVID-19 in the studied cities can be explained by high levels of humidity because different meteorological, environmental, demographic, and socioeconomic factors also plays a critical role in the disease transmission dynamics of the investigated region. The main implications of our findings here are that the demographic structure of the population, climate indicators, organization of the health system, and environmental factors (e.g., air pollution, etc.) should be considered through a systemic approach when designing effective national and regional pandemic plans directed to implement health policies for facing new variants of COVID-19 and/or new airborne diseases, in order to reduce their negative effects on health, social and economic systems.

The present study evaluated the environmental impacts of post-combustion CO₂ capture and recovery via membrane–gas absorption processes. We have used SimaPro v.9 packages with the Ecoinvent v3.5 database employing two different methods, ReCiPe 2016 Endpoint (H) and Midpoint (H), considering a fundamental methodological framework to determine the most environmentally friendly experimental condition. Life cycle impact categories were examined and assessed supposing a functional unit of 1 kgCO₂/h recovered. Fourteen environmental impact categories including global warming, ozone depletion, eutrophication, and toxicity potentials have been evaluated within the context of a gate-to-gate approach focusing on only the process stage. Simulation results showed that the maximum liquid flow rate, sweep helium flow rate together with the minimum solvent concentration demonstrated the highest impact on human health, ecosystem, and resources. The usage of pure methyldiethanolamine (MDEA) activated by piperazine as a reactive absorbent provided the lowest environmental impact due to the elimination of the energy needed to heat and evaporate water present in aqueous absorbent solutions and the prevention of the excess water consumption depending on meeting the water needed for reactive absorption of CO₂ in tertiary amine MDEA from simulated humidified flue gas stream. The study highlights the importance of LCA in the determination of an environmentally more sustainable condition during the capture and recovery of post-combustion CO₂ by gas absorption and stripping using membrane contactors in tertiary amine MDEA.