Changes of Urban and Suburban Air Quality Patterns during the Pandemic Year 2020: Longitudinal Evidence from Three Romanian Citie

Air quality in Belgrade during 2025: Seasonal dynamics, meteorological conditions, and the potential of urban forests and greenery in mitigating air pollution

Air pollution is one of the key environmental and public health problems of contemporary cities. The aim of this paper was to examine the seasonal dynamics of air pollution in Belgrade during 2025, with particular attention to the role of meteorological conditions and the potential of urban forests and green infrastructure in mitigating population exposure to pollution. The paper is based on a literature review and an analysis of publicly available secondary data, including additional sources on the structure and maintenance of urban greenery in Belgrade. The results indicate a pronounced seasonal variability in air quality, with dominant episodes of suspended particles during the colder part of the year and a greater importance of ground-level ozone during the warmer period. It was observed that meteorological conditions, particularly wind and air ventilation, play an important role in the formation and dispersion of air pollution episodes. The literature review shows that urban forests and green infrastructure can contribute to reducing population exposure to pollution, but that their effect depends on spatial scale, urban form, vegetation structure, and local climatic conditions. The most useful urban planting approach is not based on a single species, but on site-adapted combinations of tolerant trees with high leaf area and suitable crown architecture, including tree avenues and shade trees where ventilation is not obstructed. It is concluded that urban greenery represents an important complementary measure, but not a substitute for reducing emissions at the source.

Spatio-temporal variability of ambient air quality under the influence of private vehicle-dominated traffic activity in Yogyakarta Urban Area (Indonesia)

Air quality is one of the environmental issues that has become a global concern and a priority in the Sustainable Development Goals. This study aims to evaluate the ambient air quality on secondary roads in the urban area of Yogyakarta under the influence of traffic levels. The air quality variables in this study include PM2.5, PM10, CO2, HCHO, and TVOC. Data collection was conducted through observation and literature study. A total of 134 data points were collected from 37 measurement locations in this study. The data were analyzed using matching, geographic information systems (GIS), statistical methods, and descriptive approaches. The results indicate that CO2 is the only parameter significantly correlated with traffic activity. More specifically, CO2 is significantly related to motorcycles, where an increase in the number of motorcycles corresponds to a rise in CO2 levels. Spatially, there is a difference in average CO2 levels between urban and suburban areas. CO2 levels are higher in suburban areas than in the city center due to commuter traffic from surrounding areas. HCHO and TVOC do not show a significant correlation with traffic levels. Meanwhile, the number and intensity of cars on the road, although not as numerous as motorcycles, contribute to increased levels of PM2.5 and PM10. This study provides new insights into the relationship between private vehicle activity and air quality in non-industrial cities, contributing to the development of regional theories in Southeast Asia on the environmental impact of transportation activity on secondary roads. Additionally, the findings of this study imply the need for spatiotemporal traffic management, not only to prevent traffic congestion but also to control pollution levels.

Air quality management during the G20 summit: strategies for urban pollution reduction

ANALYSIS OF CHANGES IN THE LEVEL OF AIR POLLUTION BY PM2.5 FINE PARTICULATE MATTER IN KYIV UNDER WARTIME IMPACT

Geochemical Assessment of the Air Quality Index for Urban Areas (Case Study of Ben-ghazi, Al Byada, Zliten and Tripoli Cities).

One of the biggest environmental issues in cities is air pollution. Over 80% of urban dwellers are thought to be exposed to air pollution levels above the World Health Organization's (WHO) recommended limits. This work aims to compare the air quality index (AQI) with the WHO 2014 guideline during 2024 and to determine the sources of air pollution in the study areas, as well as to compare carbon dioxide (CO2) emissions in Libya with global emissions. The AirVisual Outdoor monitors were used in this work to measure AQI, PM2.5 PM10 and CO2, The finding revealed the AQI in Benghazi city during the February period was unhealthy for sensitive groups (level 3) and in April period was unhealthy (level 4), in Al Byada city was moderate throughout all periods (level 2), the air quality in  Zliten city from January to May period was unhealthy for sensitive groups (level 3) and in the air quality in Tripoli city during February period was unhealthy for sensitive groups (level 3).  Zliten city is considered the most polluted city due to the lack of infrastructure and afforestation in the city. Based on PM2.5/PM10 ratios, the natural source and coarse particles of pollution were more prevalent in the studied areas. The concentration of CO2 in Libya was approximately 441 ppm, while the global average reached about 444 ppm, indicating that the distribution of CO2 in the atmosphere is nearly uniform worldwide.

Spatio-temporal characterisation of air quality along the coastal regions of Kerala based on CPCB data