Polycyclic aromatic hydrocarbons (PAHs) are hazardous air pollutants with well-documented carcinogenic, mutagenic, and toxic effects. This study investigates the chemical composition and sources of PAHs in Kraków, a city characterized by diverse air quality challenges. PM10 and PM2.5 samples were collected during the winter seasons of 2014 and 2015, enabling a detailed assessment of PAH concentrations and their atmospheric transformations. The results indicate that PAH levels frequently exceeded European Union and World Health Organization limits, with benzo[a]pyrene (BaP) reaching peak concentrations of 38.8 ng m⁻³ in PM10 and 30.2 ng m⁻³ in PM2.5, highlighting significant health risks. To determine PAH sources, a chemical-based framework integrating diagnostic ratios, receptor modeling, and backward trajectory analysis was applied. The findings reveal that coal and biomass combustion were dominant PAH contributors, with additional influences from vehicular emissions and industrial activities. The BaP/(BaP + BeP) ratio suggested that PAHs in PM2.5 underwent more atmospheric aging than those in PM10, indicating that finer particles play a crucial role in PAH transport and transformation. Furthermore, correlations with inorganic and organic PM constituents, such as chloride and levoglucosan, underscored the mixed influence of fossil fuel and biomass burning. The study also evaluated the toxicological implications of PAHs, demonstrating that mutagenic activity exceeded toxicity levels, and finer particles posed a greater carcinogenic risk. While the exposure index suggested that short-term exposure remained within acceptable limits, long-term effects require further assessment. Given the complex interplay of emission sources and atmospheric processes, continuous monitoring and targeted mitigation strategies are essential for improving urban air quality.

The possibilities of pistachio shell biochar production on laboratory-scale gasification and pyrolysis devices have been described by several previous studies. Nevertheless, the broader results of the pistachio shell co-gasification process on pilot-scale units have not yet been properly investigated or reported, especially regarding the detailed description of the biochar acquired during the routine operation. The biochar was analysed using several analytical techniques, such as ultimate and proximate analysis (62%wt of C), acid–base properties analysis (pH 9.52), Fourier-transform infrared spectroscopy (the presence of –OH bonds and identification of cellulose, hemicellulose and lignin), Raman spectroscopy (no determination of Id/Ig ratio due to high fluorescence), and nitrogen physisorption (specific surface 50.895 m2·g⁻¹). X-ray fluorescence analysis exhibited the composition of the main compounds in the biochar ash (32.5%wt of Cl and 40.02%wt of Na₂O). From the energy generation point of view, the lower heating value of the producer gas achieved 6.53 MJ·m⁻³ during the co-gasification. The relatively high lower heating value of the producer gas was mainly due to the significant volume fractions of CO (6.5%_vol.), CH4 (14.2%_vol.), and H₂ (4.8 %_vol.), while hot gas efficiency accomplished 89.6%.

The article offers a comprehensive examination of vehicle emissions, with a specific focus on the European Union’s automotive industry. Its main goal is to provide an in-depth analysis of the factors influencing the emission of microcontaminants from light-duty vehicles and the challenges associated with their removal via exhaust aftertreatment systems. It presents statistical insights into the automotive sector and explores the relationships between vehicle categories, fuel types, and the emission of regulated and nonregulated pollutants, as well as relevant legal regulations such as the European Emission Standard. The article delves into the characteristics of vehicle exhaust, compares exhaust-gas aftertreatment systems, and introduces factors affecting emissions from gasoline engines, including downsizing, fuel composition, and engine operating parameters. It also considers the impact of driving style, start–stop systems, and related factors. Concluding, the article offers an overview of vehicle-testing procedures, including emission tests on dynamometer chassis and real driving emissions. With the growing global vehicle population and international environmental regulations, a focus on solid particles containing microcontaminants is paramount, as they pose significant risks to health and the environment. In summary, this article provides valuable insights into vehicle emissions, significantly contributing to our understanding of this crucial environmental issue.

Environmental monitoring systems play a crucial role in assessing environmental quality, detecting limits exceedances, and predicting potential ecological episodes. These systems rely on the measurement of various variables at specific locations and time intervals over an extended period. The concept of environmental monitoring encompasses the assessment of health and safety issues for public and environmental health purposes. Pollution of the atmosphere and water, climate change, and natural disasters are among the consequences of continuous industrial and municipal development and human interference in natural ecosystems. To address these challenges and to protect human lives and the environment, with a special concern on mitigating the ecological effects of industrial development, advanced technical solutions, including the technologies associated with artificial intelligence (artificial neural networks ANNs, machine learning ML) have been developed. These technologies offer powerful tools for analysing the vast amount of data collected by monitoring systems and extracting valuable insights. By applying ANNs and machine learning algorithms, environmental monitoring systems can effectively process and interpret the measured variables to assess environmental quality. Despite challenges and limitations, such as data quality and interpretability of AI models, ongoing research and interdisciplinary collaboration are paving the way for the successful implementation of AI in environmental monitoring, ultimately supporting informed decision-making and sustainable resource management.While several review papers have explored the theory of artificial intelligence (AI), here I aim to review the application of ANNs and ML, in environmental aspects, specifically in automotive and industrial emissions toxicity measurements, as well as atmospheric pollution prevention. By examining the potential of AI in these domains, the paper contributes to understanding the role of advanced technologies in environmental monitoring and protection.

Exhaust emissions from vehicles are the subject of numerous studies and legal acts. In the European Union, exhaust emissions are regulated by “Euro” emission standards, which limit emissions of gaseous pollutants such as CO, CO₂, HC, and NOx, as well as the particulate matter (PM) and particle number (PN). Solid particles consist of a number of micro-contaminants, inter alia polycyclic aromatic hydrocarbons (PAHs) and their nitrated and oxygenated derivatives. Despite their highly mutagenic and carcinogenic character, these micro-contaminants are not regulated in Euro emissions standards. This paper presents both a general discussion of the phenomenon of particulate formation in and emission from direct injection gasoline engines, as well as a wide range of results on the subject. The subject of the micro-contaminants in solid particles from modern gasoline vehicles is explored. The samples of solid particles were collected from 11 groups of vehicles according to the WLTP test methodology. Solid particles from gasoline vehicles were analyzed via various analytical techniques, including ion chromatography (IC) to measure selected anion concentrations, gas chromatography with mass spectroscopy (GC-MS) to study 16 PAHs and selected PAH derivatives, scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS) for images and elemental composition, and microwave plasma atomic emission spectroscopy (MP-AES) for qualitative screening analysis of 19 elements. The study of non-regulated compounds is crucial in efforts to establish the influence of solid particles on health and the environment. Furthermore, extended studies can provide a basis for further research on vehicle emissions or other fields, such as medicine or material engineering.