Seasonal Distribution of Atmospheric Coarse and Fine Particulate Matter in a Medium-Sized City of Northern China

Dynamic patterns of particulate matter concentration and size distribution in urban street canyons: insights into diurnal and short-term seasonal variations

Time-varying characteristics of particulate matter (PM) pollution play a crucial role in shaping atmospheric dynamics, which impact the health and welfare of urban commuters. Previously published studies on the diurnal patterns of PMs are not consistent, especially in the context of field experiments in central China, and most field studies have only focused on particles with a single particle size. This study conducted regional-scale studies across 72 street canyon sets in Wuhan, China, investigated diurnal and seasonal PM concentration variations while also evaluating various PM size and the key driving factors. During summer (July, August, and September), evergreen tree-lined street canyons maintained a stable linear trend for smaller dp particulates (i.e., PM1, PM2.5, and PM4), while deciduous street canyons exhibited a bimodal distribution. In winter (January and February), fine particulates (i.e., PM1 and PM2.5) remained a linear trend in evergreen street canyons, while deciduous street canyons show a slightly wavy fluctuating pattern. Meanwhile, it exhibited quadrimodal-peak and triple-trough patterns in both PM7, PM10, and TSP concentrations. The lowest PM concentrations were observed between 14:00 and 16:00 for all particle sizes, with decreased summer pollution (7.81% lower in PM2.5, 53.47% lower in PM10, and 50.3% lower in TSP) noted in our seasonal analysis. Among the various meteorological factors, relative humidity (RH) was identified as the dominant influencing PM factor in both summer and winter. Results from this study will help us better understand field-based air pollutant dispersion processes within pedestrian spaces while laying the groundwork for future research into street PM experiments.

Characterization of the short-term temporal variability of road dust chemical mixtures and meteorological profiles in a near-road urban site in British Columbia

Implications: Non-tailpipe emissions driven by springtime road dust in northern latitude communities is increasing in importance for air pollution control and improving our understanding of the health effects of chemical mixtures from particulate matter exposure. High-volume samples from a near-road site indicated that days affected by springtime road dust are substantively different from other days with respect to particulate matter mixture composition and meteorological drivers. The high load of trace elements in PM₁₀ on high road dust days has important implications for the acute toxicity of inhaled air and subsequent health effects. The complex relationships between road dust and weather identified in this study may facilitate further research on the health effects of chemical mixtures related to road dust while also highlighting potential changes in this unique form of air pollution as the climate changes.

Eco-sustainability analysis of precast-concrete utility poles manufacturing–A case study from Pakistan

The civil construction sector is a major contributor to the emissions of greenhouse gases (GHGs), and accounts for 40 to 50% of the total GHGs emissions produced all over the world. Concrete utility poles are considered as pillars of power distribution systems in many developing regions of the world. This study has analysed the environmental sustainability of low-tension (LT) and high-tension (HT) types of precast-concrete (PC) poles used for power distribution in Pakistan. Life cycle analysis (LCA) method is used for the assessment of environmental burdens associated with the production-manufacturing stages of these PC poles. The LCA scores are illustrated for five impact categories: climate change, acidification, eutrophication, fine-particulate matter formation and fossil resource scarcity. The significant impact scores have been depicted in climate change and abiotic resource depletion categories as; 4.60E+01 kg CO₂ eq. and 1.24 E+01 kg oil eq (for LT PC pole) and 1.55E+02 kg CO₂ eq and 3.00E+01 kg oil eq (for HT PC pole), respectively. The analytics further depict that the manufacturing of PC pole is a highly energy intensive process, with significant hauling of raw materials and finished product which causes significant emissions and impact towards climate change and fossil resources depletion. Overall, this research can offer several novel contributions to the field of sustainable development and civil engineering, including a comprehensive analysis of the environmental impacts of the manufacturing process, the development of sustainable practices and technologies and the identification of the links between sustainable development and economic growth.

New insights into submicron particles impact on visibility

The aim of the study was to analyze the impact of very fine atmospheric particles (submicron particulate matter; PM₁) on visibility deterioration. Taking into consideration not only their entirely different physio-chemical properties in comparison to a well-recognized PM₁₀ but also the origin and a growing environmental awareness of PM₁, the main research problem has been solved in few steps. At first, the chemical composition of PM₁ was determined in two selected urban areas in Poland. Measurements of meteorological parameters, i.e., air temperature and humidity, precipitation, atmospheric pressure, wind speed, and visibility, were also conducted. The next step of the work was the analysis of (1) seasonal changes of the concentration of PM₁ and its main components, (2) the influence of chemical components of PM₁ on light extinction, and (3) the influence of PM₁ and humidity on visibility. Hierarchical cluster analysis, correlation matrixes and a heat map, and classification and regression tree analysis were used. The light extinction coefficient is influenced mainly by coarse mass of PM, and PM₁-bound ammonium nitrate, organic matter, and by Rayleigh scattering. The less important in the light extinction coefficient shaping has PM₁-bound ammonium sulfate, elemental carbon, and soil. In this way, the secondary origin PM₁ components were proved to most significantly influence the visibility. The obtained results confirmed the possibility of the use of statistical agglomeration techniques to identify ranges of variation of visibility, including independent variables adopted to analyses (meteorological conditions, chemical composition of PM₁, etc.).