Assessing the spatiotemporal characteristics of urban air pollution in Ado-Ekiti and its environs, southwest Nigeria

Spatiotemporal assessment of urban PM₁₀ and population exposure using integrated satellite, meteorological, and socio-spatial data

The pollution with particulate matter is a major risk factor for population health, especially in urban environments, where the interaction between anthropogenic sources, meteorological conditions and built environment characteristics generates complex spatial patterns of exposure. In this context, the present study aims to estimate the spatial distribution of PM₁₀ concentrations and assess population exposure in a medium-sized city in Romania by integrating satellite data, in situ measurements and socio-spatial indicators. The methodology is based on MODIS-MAIAC satellite products to retrieve Aerosol Optical Depth (AOD) values, which are correlated with PM₁₀ data and meteorological variables from four ground-based air quality monitoring stations. Based on these data, a multiple regression model was developed to estimate PM₁₀ concentrations, and subsequently, a composite exposure index was constructed by integrating relevant socio-spatial indicators, such as population density, built environment characteristics, the Normalized Difference Vegetation Index (NDVI), and terrain elevation. The results highlight pronounced seasonal variability in PM₁₀ concentrations, with maximum values in the cold season (up to 41.8 μg/m 3 ) and an annual average of approximately 20.5 μg/m 3 , exceeding the thresholds recommended by the World Health Organisation but falling within the limits set by the European Union. The direct relationship between AOD and PM₁₀ is relatively weak ( R  = 0.28), but integrating meteorological variables significantly improves the model’s performance. The analysis of the composite index indicates that approximately 20.1% of the population of the Oradea Metropolitan Area lives in areas with a high predisposition to exposure, particularly near industrial areas and in densely built urban environments. The results confirm that population exposure to PM₁₀ is determined not exclusively by concentration levels but by the complex interactions among pollution, population distribution, and the characteristics of the built environment. The proposed integrated approach provides a robust tool for identifying vulnerable areas and supporting urban planning and air quality management, contributing to the development of strategies to reduce risks to human health.

Spatio-Temporal Assessment of Air Quality and AQI in Former Khanh Hoa Province, Vietnam (2021-2024)

Air pollution has become an increasingly important environmental and public health concern, particularly in rapidly urbanizing coastal provinces. This study aimed to evaluate the spatio-temporal variation characteristics of key air quality parameters (TSP, SO₂, NO₂, and CO) and the Air Quality Index (AQI) in former Khanh Hoa Province during the period 2021-2024. Periodic monitoring data collected from 28 monitoring sites across four functional zones (North, South, West, and Central) were analyzed using descriptive statistics, seasonal comparison, Pearson correlation analysis, AQI calculation, and GIS-based spatial interpolation (IDW). The results showed that SO₂ and CO concentrations significantly decreased by 62% and 22%, respectively (p<0.05), while NO₂ remained relatively stable and TSP showed signs of increasing, particularly in 2024. TSP was identified as the dominant pollutant, accounting for more than 95% of AQI deterioration and frequently exceeding the annual average standard in the Central region. Overall air quality was generally classified as “Good” and “Moderate”; however, localized pollution hotspots and short-term unhealthy AQI events were observed, especially during the dry season in urbanized areas with high traffic density and intensive construction activities. Pearson correlation analysis revealed that humidity and wind speed played important roles in pollutant dispersion and washout effects, while noise levels showed significant positive correlations with TSP, NO₂, and CO, indicating the strong influence of transportation-related emissions. These findings suggest that air quality management should prioritize TSP source control, particularly in the Central region, and strengthen seasonal monitoring strategies to support sustainable environmental management in rapidly developing coastal provinces of Vietnam.

Comparative Evaluation of Ambient Air Pollution in Owerri Urban and Its Environs, South-eastern Nigeria

Rapid urbanization and increased anthropogenic activities have intensified air pollution in many Nigerian cities, posing significant environmental and public health risks. This study comparatively evaluated ambient air pollution levels in Owerri urban and its surrounding environments in southeastern Nigeria. Seven sampling locations representing urban, peri urban, and relatively less disturbed areas were selected for field monitoring. Concentrations of major atmospheric pollutants including hydrogen sulphide (H₂S), nitrogen dioxide (NO₂), carbon dioxide (CO₂), carbon monoxide (CO), volatile organic compounds (VOCs), particulate matter (PM₂.₅) and particulate matter (PM₁₀) were measured using portable air quality monitoring instruments. Spatial coordinates were recorded using a Global Positioning System and spatial distribution patterns were analyzed using Inverse Distance Weighted interpolation within a Geographic Information System environment. Results revealed considerable spatial variation in pollutant concentrations across the study area. Carbon dioxide exhibited the highest overall concentrations, indicating the dominance of combustion related activities. Elevated concentrations of CO, PM₂.₅ and PM₁₀ were observed around high traffic and commercial locations, particularly around the World Bank, Orji and Egbu axes of Owerri. Lower concentrations were recorded in less densely populated peripheral areas. The spatial analysis revealed distinct pollution hotspots associated with vehicular emissions, generator use, road dust resuspension and commercial activities. The study highlights the growing air quality challenges in Owerri and recommends continuous air quality monitoring, stricter emission control policies and sustainable urban planning strategies to mitigate pollution and protect public health.

Socioeconomic impacts and spatiotemporal assessment of environmental pollution in Mekelle City, Northern Ethiopia

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

Assessment of the influence of meteorological and vehicular factors on the deposition of atmospheric sedimentable dust in Huánuco, Peru