Impacts of urbanization on air quality and the related health risks in a city with complex terrain

Abstract

Abstract. Urbanization affects air pollutants via urban expansion and emission growth, thereby inevitably changing the health risks involved with air pollutants. However, the health risks related to urbanization are rarely estimated, especially for cities with complex terrain. In this study, a highly urbanized city with severe air pollution and complex terrain (Chengdu) is selected to explore this issue. The effects of urban expansion are further compared with emission growth because air quality management is usually achieved by regulating anthropogenic emissions. Air pollution in Chengdu was mainly caused by PM2.5 and O3 from 2015 to 2021. PM2.5 pollution tended to appear in cold months (November to February) owing to the blocking of air and the stable atmospheric layer, whereas O3 pollution was likely to occur in warm months (April to August) that experience high-temperature and strong-sunlight conditions and are dominated by high-pressure systems. From 2015 to 2021, the 7-year annual average of premature mortality from all non-accidental causes (ANACs) due to PM2.5 and O3 was 9386 (95 % confidence interval (CI) of 6542–11 726) and 8506 (95 % CI of 4817–11 882), respectively. Based on the characteristics of PM2.5 and O3, six numerical experiments were conducted to investigate the impacts of urban expansion and emission growth on the health risks related to air pollutants. The results show that urban land use led to an increase in the air temperature and boundary layer height compared with cropland, which was conducive to the diffusion of PM2.5. Thus, the monthly average surface PM2.5 concentrations decreased by 10.8 µg m−3 (7.6 %) in January. However, the monthly average daily maximum 8 h average (MDA8) O3 concentrations increased by 10.6 µg m−3 (6.0 %) in July owing to the stronger photochemical production and better vertical mixing during daytime. In this case, premature mortality from ANACs due to PM2.5 decreased by 171 (95 % CI of 129–200, or about 6.9 %) in January, and that due to O3 increased by 203 (95 % CI of 122–268, or about 9.5 %) in July. As for the effects of emission growth, the monthly average PM2.5 and MDA8 O3 concentrations increased by 23.9 (16.8 %) and 4.8 µg m−3 (2.7 %), respectively, when anthropogenic emissions were taken into account. Premature mortality from ANACs due to PM2.5 and O3 then increased by 388 (95 % CI of 291–456, or about 15.7 %) and 87 (95 % CI of 54–112, or about 4.1 %), respectively. From a health risk perspective, the effects of urban land use on the health risks related to PM2.5 are about half that of anthropogenic emissions, whereas the effects of urban land use on the health risks related to O3 can be 2 times that of anthropogenic emissions. This emphasizes that, in addition to regulating anthropogenic emissions, urban planning is also important for urban air quality, especially for secondary pollutants like O3.

Transition metals concentration within the PM10 fraction of atmospheric suspended particulate matter – case study, Craiova, 2021

“…Regarding the determination of the concentration of the most significant toxic metals within PM10, it must be specified that, in all cases, the concentration, which was initially recorded in μg/L, was afterwards transformed into another unit, namely μg/m 3 , by dividing its value to twenty times the drawn air volume, expressed in m 3 ; in what follows (Table 2), both variants will be presented each time [15].…”

“…The impact plate of the pump was cleaned and greased with silicone Vaseline (Figure 1a). On a digital screen, the volume of air sampled was displayed, in operated m 3 , with an accuracy of 0.01 m 3 (the flow rate was set at constant, at 2.3 m 3 /h, in accordance with the standard EN 12341:2014 [22], which was subsequently updated [23]). Changing filters at the measurement site was facilitated by using a quick-change filter holder (Figure 1b).…”

“…Identifying and minimizing the particulate matter sources must be a great concern [2,3], as particle size is directly related to the potential to cause effects. Particles in the PM10 fraction, i.e., those with diameters smaller than 10 microns, are inhalable particles, which can pass through the nose and throat, potentially causing inflammation and intoxication [4,5].…”

Coastal wetlands of Indus River Delta are under risk due to reclamation: A spatiotemporal analysis during the past 50 years from 1972 to 2022

“…Wetlands protection and restoration efforts are so critical for sustaining these precious ecosystems.Population growth and urbanization, which have resulted in the extension of built-up areas, can be ascribed to the rise in reclamation settlement areas seen in this study(Chen et al, 2023). The expansion of built-up regions can have severe environmental consequences, such as increased air and water pollution, habitat loss, and changes in microclimate(Zhan et al, 2023). Furthermore, urbanization can result in a loss of biodiversity as well as the loss of important ecosystem services such as ood control and water ltration(Chen et al, 2022).…”

A comprehensive study on the spatial and temporal variation of BTEX and asbestos in the northwest of Iran: Human risk assessment

“…Efforts to reduce it have had limited success despite various initiatives [ 1 ]. Rapid technological development, urbanization, and population growth have exacerbated the issue, particularly its impact on health [ 2 ]. Ambient air pollution is associated with premature deaths and numerous diseases, like cancer, cardiovascular, respiratory, reproductive, endocrine, and neurological diseases [ [3] , [4] , [5] , [6] , [7] ].…”