Spatiotemporal analysis of pedestrian exposure to submicron and coarse particulate matter on crosswalk at urban intersection

Assessment of Individual-Level Exposure to Airborne Particulate Matter during Periods of Atmospheric Thermal Inversion

“…A similar trend is present for the period with ATIs. Pedestrians are exposed to varying concentrations of PM throughout the urban environment based on different types of road, traffic volume, time of day, and season [ 55 ], or specific high-exposure events, e.g., queuing by or walking across a crosswalk [ 56 ], which influence their cumulative exposure. As they move slower and cover less distance than cyclists, the variability can be lower, moreover, they are less frequently exposed to direct traffic exhaust than cyclists.…”

How does COVID-19 lockdown affect air quality: Evidence from Lanzhou, a large city in Northwest China

“…Our analysis also has several deficiencies, and certain limitations must be noted: (1) During completing this study (October and November 2022), a new COVID-19 outbreak occurred in Lanzhou, but we were prevented from including it in our study period because of the lag in data collection. (2) We estimated the impact of the most common socioeconomic background and epidemic condition factors on air quality for the lockdown; however, the impact of other factors such as urban greening ( Zheng et al, 2021 ), road network ( Wang et al, 2021d ), should not be ignored and deserves further research. (3) This study was based on ground-based observation, and attempts might be made to enrich the data sources in our future studies, Site sampling ( Kalisa and Adams, 2022 ), satellite observation and remote sensing ( Naqvi et al, 2021 ; Srivastava et al, 2021 ), and multi-source fusion data (Mamtimin et al, 2022; Campanelli et al, 2021 ).…”

“…Simultaneously, the residents' income has continued to grow and the number of vehicles, particularly private cars, has increased rapidly, making the transport sector an increasingly large air pollution source ( Huang et al, 2017 ; Zhao et al, 2018 ; Ye, 2017 ). Moreover, Lanzhou's river-valley topography and low-wind meteorological conditions are unfavorable for pollutant diffusion, causing their easy accumulation in the city sky ( Tang et al, 2022 ; Wang et al, 2021c ; Chen et al, 2020). Nevertheless, the number of days with good air quality has been increasing yearly and reached 85.2% in 2020, an increase of 62 days from 2014, due to the air pollution prevention measures adapted, such as strengthening of motor vehicle exhaust and industrial pollution control ( Lanzhou Ecology and Environment Bureau, 2021 ).…”

“…Some studies have further confirmed the causal relationship between epidemic control measures and air quality/air pollution changes employing the difference-in-differences models (He et al, 2020), regression discontinuity in time model ( Zeng and Wang, 2022 ), counterfactual analysis ( Dong et al, 2022 ), Gaussian process regression approach ( Velásquez and Lara, 2020 ), and Meta analyses ( Faridi et al, 2021 ).Studies on associations between COVID-19 lockdown and air quality cover several geographical areas, but most studies in China have focused on eastern and central regions ( Dong et al, 2022 ; Huang et al, 2020 ), very few studies have concerned the western cities of China, not contributing to a understanding of the cross-regional heterogeneous in this association. Lanzhou City is an essential heavy-industrial base and integrated transportation hub in the northwestern China (He et al, 2022), and the location of the first photochemical smog incident identified in China ( Wang et al, 2021c ; Wang et al, 1999). In the late 1990s and earlier this century, Lanzhou was ranked as one of the top ten polluted cities worldwide (Chen et al, 2020).…”

Exposure of Malaysian Children to Air Pollutants over the School Day

“…There is additional exposure in busy drop-off and pick-up zones. Specific studies show that some locations on the route to school can have high concentrations: bus stops [34] and pedestrian crossings [35]. However, travel is not necessarily the dominant contributor to daily exposure [18,36,37].…”