The variations in physicochemical properties of airborne particles collected during a typical transition from haze to dust were investigated using single particle analysis with transmission and scanning electron microscopes combined with online measurement of chemical compositions of airborne particles in Beijing in February 2013. The transition was divided into three phases based on the weather condition. During haze pollution (Phase 1), gaseous and particle pollutants enhanced gradually. Results from single particle analysis showed that more coatings and more anthropogenic elements (e.g., S) appeared on the surface of fine and coarse particles, which was probably caused by efficient aqueous-phase reactions under high humidity (70%) condition. Phase 2 was dust intrusion episode. PM reached over 1000 μg m. Larger fractions of mineral particles and bare-like soot particles were observed in fine particles, while the fraction of secondary particles with coatings decreased. The proportion of black carbon in submicron particles also increased. Photochemical oxidation in gas phase likely dominated in secondary formation under high O concentration. After the dust episode (Phase 3), secondary formation enhanced obviously. Soot aged quickly and had a larger mode of 0.45 μm than the other phases. The size modes of airborne fine particles during Phases 1 and 3 were 0.35 μm, which were a bit larger than that during Phase 2 (0.24 μm). These results indicate that dust plumes accompanied with strong wind brought mineral particles in both fine and coarse modes and freshly emitted particles with smaller sizes, and swept away pre-presence air pollutants. This study could provide detailed information on the physicochemical properties of airborne particles during typical severe pollution processes in a short time. Such short-term change should be taken into account in order to more accurately assess the environmental, climatic and health-related effects of airborne particles.
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http://dx.doi.org/10.1016/j.scitotenv.2020.143081 | DOI Listing |
Sci Total Environ
January 2025
Institute of Environmental Assessment and Water Research, CSIC, 08034 Barcelona, Spain. Electronic address:
Airborne quasi-ultrafine particle samples were collected from different outdoor sites in Barcelona (NE Spain, 35 samples) and the Valencia subway (about 400 km south of Barcelona, 3 samples). Locations and schedules were designed to cover cold and warm seasons and to represent the impact of different types of transport (cars, trains, ships, and planes). Extracts from PTFE filters (methanol:dichloromethane 1:2) were used to test toxic effects in human cell lines (Induction of reactive oxygen species, inflammatory response) and in zebrafish embryos (expression of xenobiotic response-related genes, cyp1a1, gsa1 and hao1).
View Article and Find Full Text PDFEnviron Pollut
January 2025
Department of Public Health, China Medical University, Taichung City, Taiwan. Electronic address:
Marine litter and microplastics (MPs) represent pressing environmental challenges. However, the impact of marine litter on airborne MPs near marine litter hotspot remains unexplored. In this study, we simultaneously collected airborne MPs, weather factors, and air pollutants in a village near a marine litter hotspot across different seasons in Taiwan.
View Article and Find Full Text PDFJ Occup Environ Hyg
January 2025
Air Pollution Research Center, Iran University of Medical Sciences, Tehran, Iran.
The pathogenic potential of airborne particles carrying the SARS-CoV-2 viral genome was examined by considering the size distribution of airborne particles at given distances from the respiratory zone of an infected patient after coughing or sneezing with a focus on time, temperature, and relative humidity. The results show an association between the size distribution of airborne particles, particularly PM and PM, and the presence of viral genome in different stations affected by the distance from the respiratory zone and the passage of time. The correlation with time was strong with all the dependent factors except PM.
View Article and Find Full Text PDFComput Methods Programs Biomed
January 2025
Faculty of Engineering Sciences, Kyushu University, Fukuoka, Japan.
Background And Objective: Coughing events are eruptive sources of virus-laden droplets/droplet nuclei. These increase the risk of infection in susceptible individuals during airborne transmission. The oral cavity functions as an exit route for exhaled droplets.
View Article and Find Full Text PDFEClinicalMedicine
January 2025
WEISS Centre, University College London, UK.
Background: The COVID-19 pandemic highlighted the need for improved infectious aerosol concentrations through interventions that reduce the transmission of airborne infections. The aims of this review were to map the existing literature on interventions used to improve infectious aerosol concentrations in hospitals and understand challenges in their implementation.
Methods: We reviewed peer-reviewed articles identified on three databases, MEDLINE, Web of Science, and the Cochrane Library from inception to July 2024.
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