Snapshots of wintertime urban aerosol characteristics: Local sources emphasized in ultrafine particle number and lung deposited surface area

Teemu Lepistö; Luis M F Barreira; Aku Helin; Jarkko V Niemi; Niina Kuittinen; Henna Lintusaari; Ville Silvonen; Lassi Markkula; Hanna E Manninen; Hilkka Timonen; Pasi Jalava; Sanna Saarikoski; Topi Rönkkö

doi:10.1016/j.envres.2023.116068

Snapshots of wintertime urban aerosol characteristics: Local sources emphasized in ultrafine particle number and lung deposited surface area

Environ Res. 2023 Aug 15;231(Pt 1):116068. doi: 10.1016/j.envres.2023.116068. Epub 2023 May 5.

Authors

Affiliations

¹ Aerosol Physics Laboratory, Physics Unit, Faculty of Engineering and Natural Sciences, Tampere University, Tampere, 33014, Finland. Electronic address: teemu.lepisto@tuni.fi.
² Atmospheric Composition Research, Finnish Meteorological Institute, Helsinki, 00101, Finland.
³ Helsinki Region Environmental Services Authority HSY, Helsinki, 00066, Finland.
⁴ Aerosol Physics Laboratory, Physics Unit, Faculty of Engineering and Natural Sciences, Tampere University, Tampere, 33014, Finland.
⁵ Inhalation Toxicology Laboratory, Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, 70211, Finland.

PMID: 37149021
DOI: 10.1016/j.envres.2023.116068

Abstract

Urban air fine particles are a major health-relating problem. However, it is not well understood how the health-relevant features of fine particles should be monitored. Limitations of PM_2.5 (mass concentration of sub 2.5 μm particles), which is commonly used in the health effect estimations, have been recognized and, e.g., World Health Organization (WHO) has released good practice statements for particle number (PN) and black carbon (BC) concentrations (2021). In this study, a characterization of urban wintertime aerosol was done in three environments: a detached housing area with residential wood combustion, traffic-influenced streets in a city centre and near an airport. The particle characteristics varied significantly between the locations, resulting different average particle sizes causing lung deposited surface area (LDSA). Near the airport, departing planes had a major contribution on PN, and most particles were smaller than 10 nm, similarly as in the city centre. The high hourly mean PN (>20 000 1/cm³) stated in the WHO's good practices was clearly exceeded near the airport and in the city centre, even though traffic rates were reduced due to a SARS-CoV-2-related partial lockdown. In the residential area, wood combustion increased both BC and PM_2.5, but also PN of sub 10 and 23 nm particles. The high concentrations of sub 10 nm particles in all the locations show the importance of the chosen lower size limit of PN measurement, e.g., WHO states that the lower limit should be 10 nm or smaller. Furthermore, due to ultrafine particle emissions, LDSA per unit PM_2.5 was 1.4 and 2.4 times higher near the airport than in the city centre and the residential area, respectively, indicating that health effects of PM_2.5 depend on urban environment as well as conditions, and emphasizing the importance of PN monitoring in terms of health effects related to local pollution sources.

Keywords: Airport; Biomass burning; Human respiratory tract; Mobile laboratory; Traffic; Ultrafine particles.

MeSH terms

Air Pollutants* / analysis
Air Pollution* / analysis
COVID-19*
Communicable Disease Control
Environmental Monitoring / methods
Humans
Lung / chemistry
Particle Size
Particulate Matter / analysis
Respiratory Aerosols and Droplets
SARS-CoV-2
Soot
Vehicle Emissions / analysis

Substances

Particulate Matter
Air Pollutants
Soot
Vehicle Emissions