Heavy metals represent a class of pollutants detected at concentrations lower than 10 ppm in different matrices that are intensively monitored due to having a major impact on human health. Industrial activities including mining, agriculture, and transport, determine their presence in different environments. Corrosion phenomena of various installations, volcanic eruptions, or atmospheric deposition on the soil surface and in water can contaminate the respective environments. Atmospheric pollutants in the form of suspended dust particles with diameters below 10 microns are predominantly composed of different metallic species from Cd, Cr, Cu, Ni, etc. This paper presents a review of the main sources and types of heavy metals present in the atmosphere in the composition of particulate matter (PM), highlighting the main mechanisms of occurrence and detection techniques, including the impact on bio-geo-chemical processes in the soil and food chain, in close correlation with their impact on environment and human health. The purpose of this review is to highlight the current level of knowledge regarding the global situation of heavy metals in PM and to identify gaps as targets for future research.

This paper focuses on identifying the human health risks as a result of the presence of polycyclic aromatic hydrocarbons (PAHs) in groundwater due to the Bucharest landfill leakages. The main subjects were neighboring areas as the main receptors. The functional landfill located near the capital of Romania was selected as a case study. Fluorene (Pf), phenanthrene (Phe), anthracene (Ant), fluoranthene (Flu) and pyrene (Pyr) were detected using gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis. The health risks for receptors via ingestion and dermal exposure scenarios were developed considering dermal contact once per day during showering for 20 min and regular ingestion of the groundwater most contaminated with PAHs at a rate of 2 L per day. The concentration ranges of PAHs in groundwater wer <0.0010–0.0037 μg L⁻¹ for Pf, 0.0014–0.0065 μg L⁻¹ for Phe, <0.0010–0.0013 μg L⁻¹ for Ant, <0.0010–0.0011 μg L⁻¹ for Flu, and 0.0030–0.0032 μg L⁻¹ for Pyr. The rest of the PAHs were under the limit of detection. Both the cumulative hazard and risk quotient are well below the value of 1, which indicates a significant low risk for the ingestion of PAH-contaminated groundwater. However, the risk due to daily groundwater consumption and skin contact is minimal.

Air pollution caused by CO₂ emissions has become a global issue of vital importance, posing irreversible risks to health and life when concentration of CO₂ becomes too high. This study aims to estimate the CO₂ emissions and carbon footprint of the public transport bus fleet in Bucharest, with a comparative analysis of greenhouse gas (GHG) emissions generated by diesel and electric buses of the Bucharest Public Transport Company (STB S.A.) in the period 2021–2024, after the modernization of the fleet through the introduction of 130 hybrid buses and 58 electric buses. In 2024, the introduction of electric buses and the reduction in diesel bus mileage reduced GHG emissions by almost 13% compared to 2023, saving over 11 kilotons of CO_2e. There was also a 2.68% reduction in the specific carbon footprint compared to the previous year, which is clear evidence of the potential of electric vehicles in achieving decarbonization targets. We have also developed two strategies, one for 2025 and one for the period 2025–2030, replacing the aging fleet with electric vehicles. This demonstrates the relevance of electric transport integrated into the sustainable development strategy for urban mobility systems and alignment with European standards, including improving air quality and living standards.