The paper aims to analyse the main air pollutants considered responsible for most premature deaths and illnesses: particulate matter, nitrogen dioxide, sulphur dioxide, and ground-level ozone. The research methodology used is based on the analysis and synthesis of information from the scientific literature on air pollution, identification of sources of air pollutants and their implications for human health. The principal research method used in the paper is content analysis. The importance of this publication is to expand and improve the content of the literature in the domain. The contributors point out that air pollution is currently the highest environmental risk affecting human health. Every year, this type of pollution causes around 400,000 premature deaths in the European Union and causes various illnesses: respiratory, strokes and lung diseases, cardiovascular, liver and blood diseases. Emissions of air pollutants are mainly the result of human actions: heating of homes, road transport, the energy sector, industry, agriculture and others in much smaller proportions. The authors' investigation revealed that, in overall terms, air quality has not improved with the reduction of greenhouse gas emissions. In conclusion, the authors highlight the need for environmental policies that contribute to reducing emissions and improving air quality, intending to further safeguard human health and the environment.

The outbreak of the coronavirus pandemic (COVID-19) first occurred in late December 2019 at the Hunan Seafood Market in Wuhan, China, and was declared an international public health emergency in a matter of weeks by the World Health Organization. The coronavirus disease (COVID-19) affects every area of human life, including the environment. Measures are taken to control the spread of the virus and the slowdown in economic activities have significant positive effects on the environment. Through this study, the authors intend to track the impact caused by the COVID-19 pandemic on the environment by analyzing the available scientific literature. The study indicates that the pandemic situation significantly improves air quality in various cities around the world, reduces greenhouse gas emissions, reduces water pollution and noise, and reduces pressure on tourist destinations, which can help restore ecological systems. It is noted that there are some negative consequences of the pandemic, such as the increase in medical waste through the use and disposal of disinfectants, masks, and gloves but also the burden of untreated waste that endangers the environment continuously. It seems that shortly after the pandemic the economic activities will return and the situation could change. Therefore, this study highlights the potential positive impacts of the pandemic on the environment in the long term. It is expected that the correct implementation of the proposed strategies can be useful for the global sustainability of the environment.