COVID-19 Impact on the Environment and Sustainable Development

The study investigated the changes that occurred in the Mexican power sector before, during, and after the COVID-19 pandemic and its repercussions on the electricity sector and energy sustainability goals. The study was based on the variability of the installed capacity, consumption, generation, and demand of the National Electric System (SEN), covering the period from 2017 to 2021. The data were collected from the Development of the National Electric System (PRODESEN), the Ministry of Energy, the National Energy Balance, and the government’s official website. The results indicated that installed capacity and generation increased by 22.83% and 27.86%, respectively, despite the pandemic. This growth was attributed to clean energy, mainly from photovoltaic solar and wind sources. Another finding was that the gross domestic product (GDP), consumption, and demand were seriously affected by COVID-19. They had a fall of 8.2%, 2.2%, and 4.4%, respectively, which translates into a significant economic lag and a slowdown in energy self-sufficiency and the Mexican Energy Transition (TEM). Moreover, the objective of generating 35% and 40% of electrical energy through clean energy will be achieved by 2031 and 2035, instead of 2021 and 2035, respectively. Full article

Droplet transmission is a critical pathway for the spread of respiratory infectious viruses. A thorough understanding of the mechanisms of droplet dispersion within subway carriages is crucial to curb the widespread transmission of the virus. This study utilizes computational fluid dynamics (CFD) to establish a full-scale numerical model of a subway carriage. The numerical model and droplet evaporation behavior are validated using experimental data and literature. The impact of primary parameters such as the initial droplet size, release velocity, release position, relative humidity, and passenger density on the droplet diffusion and probability of infection for passengers is investigated. The results indicate that large droplets (100 μm) are deposited on the carriage floor before complete evaporation, while tiny droplets (10 μm) evaporate rapidly, leading to a longer suspension time in the air within the carriage. The infected passenger’s position influences the ventilation system’s efficiency in removing the droplets; removal takes significantly longer when the infected passenger is closer to the carriage end. Additionally, a low relative humidity (35%) and high passenger density (4 p/m²) result in more droplets being trapped by passengers’ bodies. The infection probability for passengers depends on the initial size and quantity of droplets trapped by their bodies. Maintaining higher relative humidity levels and limiting the passenger numbers within the subway carriage can reduce the number of droplets captured by passengers’ bodies, thus helping to reduce the infection probability of fellow passengers. Full article

This retrospective study aimed to estimate the differences between selected indicators of physical fitness and body composition in young tennis players during the COVID-19 pandemic (2020 and 2021) and their values as predicted using the pre-pandemic trend (2015–2019). Data were collected from selected boys (mean ± SD; 13.2 ± 1.7 years) and girls (13.1 ± 1.9 years) during annual tests. Data were analyzed with linear mixed-effects models for males and females, separately, to predict body composition and physical fitness test scores, adjusting for age and pre-pandemic trends in the data. Compared with expected values, body fat mass increased in boys (2020: 0.68; 0.44–0.92, 2021: 1.08; 0.72–1.43), whereas muscle mass decreased (2020: −0.22; −0.34–−0.10, 2021: −0.28; −0.46–−0.10) throughout the pandemic. Interestingly, boys’ age-adjusted squat jump test scores improved relative to their expected scores during COVID-19 (2020: 0.19; 0.00–0.38, 2021: 0.35; 0.06–0.63). No other differences between predicted and measured values were noted across the observation period. The results of this study suggest that the sustained reduction in sports activity caused by the pandemic may have negatively affected the body composition of athletes; however, this did not affect selected performance indicators. Full article

There is little doubt that final victories over pandemics, such as COVID-19, are attributed to herd immunity, either through post-disease convalescence or active immunization of a high percentage of the world’s population with vaccines, which demonstrate protection from infection and transmission and are available in large quantities at reasonable prices. However, it is assumable that humans with immune defects or immune suppression, e.g., as a consequence of allograft transplantation, cannot be immunized actively nor produce sufficient immune responses to prevent SARS-CoV-2 infections. These subjects desperately need other strategies, such as sophisticated protection measures and passive immunization. Hypertonic salt solutions attack vulnerable core areas of viruses; i.e., salt denatures surface proteins and thus prohibits virus penetration of somatic cells. It has to be ensured that somatic proteins are not affected by denaturation regarding this unspecific virus protection. Impregnating filtering facepieces with hypertonic salt solutions is a straightforward way to inactivate viruses and other potential pathogens. As a result of the contact of salt crystals on the filtering facepiece, these pathogens become denatured and inactivated almost quantitatively. Such a strategy could be easily applied to fight against the COVID-19 pandemic and other ones that may occur in the future. Another possible tool to fight the COVID-19 pandemic is passive immunization with antibodies against SARS-CoV-2, preferably from human origin. Such antibodies can be harvested from human patients’ sera who have successfully survived their SARS-CoV-2 infection. The disadvantage of a rapid decrease in the immunoglobulin titer after the infection ends can be overcome by immortalizing antibody-producing B cells via fusion with, e.g., mouse myeloma cells. The resulting monoclonal antibodies are then of human origin and available in, at least theoretically, unlimited amounts. Finally, dry blood spots are a valuable tool for surveilling a population’s immunity. The add-on strategies were selected as examples for immediate, medium and long-term assistance and therefore did not raise any claim to completeness. Full article

This paper investigates the month-wise impact of COVID-19 conditions on residential load due to people’s presence at home during office hours in Memphis city, Tennessee, USA. The energy consumption patterns of four consumers are analyzed based on the data available from pre-COVID to continuing COVID-19 situations. It is observed that the energy consumptions from April 2020 to June 2021 for all families have increased during office hours than that of pre-COVID months. Therefore, the impacts of the increased loads on distribution transformer are analyzed in terms of hottest spot, top-oil temperature, and loss of transformer life. Moreover, an experimental setup is made to produce the harmonics in currents of non-linear residential load which has detrimental effects on temperature rise of distribution transformer. In addition, this work proposes implementation of harmonic filter at the load side considering the impact of harmonics produced by loads to reduce the temperature rise due to the increased load consumption and presence of harmonics in currents produced by the load. The rise in temperatures and the loss of life of distribution transformer with and without the proposed solutions are simulated in MATLAB to show the efficacy of the proposed solution. Moreover, cost value analysis among different methods, which can be implemented to reduce the adverse impact on distribution transformer, are provided to rank the available methods. Full article

If it is not adequately managed, the waste from healthcare facilities containing infectious material poses a risk to the general public and the natural environment. As a result, hospitals must ensure that their waste management policies do not add to the dangers posed to both human health and the environment. In this study, we aimed to determine the effect that varying doses of disinfectant in conjunction with andosol soil had on the total number of bacteria present in the medical waste generated by three hospitals in Semarang City, Indonesia. According to the findings of the study, the most efficient method for decreasing the overall number of microbial colonies by 93% was a combination involving soil (at a percentage of 30) and chlorine (at a concentration of 0.75 ppm). As a consequence of this, and due to the limited technology available, this straightforward method can become an alternative for the healthcare industry in managing medical waste before dumping or incinerating it. Hospitals have been advised to discontinue the practice of directly burning, disinfecting, or transporting waste to disposal locations before it receives treatment. This can help reduce the risk of pandemics, as the correct disposal of medical waste can control infection sources. Full article

A network model of epidemic spread accounting for inhomogeneous population district division is investigated. Motivated by the COVID-19 pandemic, we analyze the effects of infection development in the area, for example, of a city divided into several population districts. The districts are characterized by a certain intensity of contact inside and with inter-district communication that can be generally controlled by the authorities. Specifically, we consider the effect of the central district, which is the hub of infection. We investigate how the interaction strength influences the city’s level of epidemic development. We obtained that the final infected amount in the district rises with an increasing degree of connection with the hub. However, the model situation was not limited by the first outbreak but included the subsequent waves of infection. We obtained that the appearance and disappearance of subsequent waves of infection essentially depended on the intensity of communication with the infected hub. Our results suggest the mechanism where stricter communication policy can negatively affect the subsequent infection waves. Full article

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. Full article

Sustainable business models can help us move beyond the current consumer society and integrate sustainability into our lifestyles. The COVID-19 crisis was a strong test of sustainability for these models. In our study, we assessed which business models are highly dependent on the economic cycle and are highly embedded in consumer society. We conducted our research at the height of the second wave of the pandemic and asked university students about changes in their consumption patterns and their expectations for the future. We carried out cluster analysis on our sample of 622 respondents. We were interested in the extent to which participation in certain business models could be associated with the rebound effect that could be predicted after the epidemic. The stronger this effect, the more embedded a sustainable business model is in consumer society and the less able it is to reduce its environmental impacts in the long term. We found that resource efficiency, the sharing economy, and digitalization fall into this category. Participation in sufficiency and stewardship-based business models predicted much less rebound impact. These models showed more clearly the sustainability characteristics of sustainable business models. Full article