TY - JOUR
T1 - Snapshots of wintertime urban aerosol characteristics
T2 - Local sources emphasized in ultrafine particle number and lung deposited surface area
AU - Lepistö, Teemu
AU - Barreira, Luis M.F.
AU - Helin, Aku
AU - Niemi, Jarkko V.
AU - Kuittinen, Niina
AU - Lintusaari, Henna
AU - Silvonen, Ville
AU - Markkula, Lassi
AU - Manninen, Hanna E.
AU - Timonen, Hilkka
AU - Jalava, Pasi
AU - Saarikoski, Sanna
AU - Rönkkö, Topi
N1 - Funding Information:
This work has received funding from BC Footprint project (530/31/2019) funded by Business Finland , participating companies and municipal actors.
Funding Information:
This work was supported by the European Union's Horizon 2020 research and innovation programme under grant agreement No 814978 (TUBE: Transport-derived ultrafines and the brain effects); BC Footprint project (530/31/2019) funded by Business Finland, participating companies and municipal actors; Academy of Finland Flagship funding Atmosphere and Climate Competence Centre, ACCC (grant no. 337552, 337 551); and Finnish Foundation for Technology Promotion.Despite the high ultrafine particle concentrations, the average PM2.5 and BC concentrations during the measurements in Airport B were low (Table 4: 5.0 and 0.84 μg/m3, respectively). By taking the regional background (PM2.5: 3–4 μg/m3 and BC: 0.3–0.4 μg/m3) into account, the results suggest that the air traffic was not a major source of PM2.5 or BC. This result is supported with the particle number size distributions and the SP-AMS which did not observe any mass concentration peaks near the airport due to the small particle size. The results near the airport suggest that the high PN concentrations measured in the residential area during the western wind (Fig. S4) could be originated from the airport (see also Hudda et al. 2014 and Keuken et al., 2015), emphasizing the role of air traffic in urban air quality even far away from the airport. The major ultrafine particle emissions from aircrafts have been observed in previous studies, but the lower limits of the measurement size ranges have typically been larger than 2.5 nm (Stacey, 2019). Thus, according to our results, despite that the air traffic has been known to be a major emission source of ultrafine particles, a significant fraction of these particles are in previously unobserved size ranges, emphasizing the need to study nanocluster aerosol emissions of aviation. Furthermore, these high ultrafine particle concentrations are not easily detected with particle mass measurement and the emissions can increase the PN concentrations clearly above the WHO's suggested limit for high short-term PN (20 000 1/cm3). The results emphasize the need for long-term measurements of ultrafine particles, especially the sub 10 nm fraction, near airports, and highlight the importance of the chosen lower limit of PN measurement size range, which should be recognized e.g., in the future regulations.This work is part of the European Union's Horizon 2020 research and innovation programme under grant agreement No 814978 (TUBE: Transport-derived ultrafines and the brain effects). This work has received funding from BC Footprint project (530/31/2019) funded by Business Finland, participating companies and municipal actors. We gratefully acknowledge Academy of Finland Flagship funding Atmosphere and Climate Competence Centre, ACCC (grant no. 337552, 337551). Teemu Lepistö thanks Finnish Foundation for Technology Promotion for supportive funding for the doctoral studies. We wish to thank Tampere Microscopy Centre for the analysis of S/TEM and EDS samples as well as HSY's measurement team and Stanislav Demyanenko for their valuable work during the measurement campaign. The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and READY website (https://www.ready.noaa.gov) used in this publication.
Funding Information:
Teemu Lepistö thanks Finnish Foundation for Technology Promotion for supportive funding for the doctoral studies.
Funding Information:
This work is part of the European Union’s Horizon 2020 research and innovation programme under grant agreement No 814978 (TUBE: Transport-derived ultrafines and the brain effects).
Funding Information:
This work was supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 814978 (TUBE: Transport-derived ultrafines and the brain effects); BC Footprint project (530/31/2019) funded by Business Finland , participating companies and municipal actors; Academy of Finland Flagship funding Atmosphere and Climate Competence Centre, ACCC (grant no. 337552, 337 551); and Finnish Foundation for Technology Promotion .
Funding Information:
We gratefully acknowledge Academy of Finland Flagship funding Atmosphere and Climate Competence Centre, ACCC (grant no. 337552, 337551).
Publisher Copyright:
© 2023 The Authors
PY - 2023/8/15
Y1 - 2023/8/15
N2 - 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 PM2.5 (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 PM2.5, 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 PM2.5 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 PM2.5 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.
AB - 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 PM2.5 (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 PM2.5, 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 PM2.5 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 PM2.5 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.
KW - Airport
KW - Biomass burning
KW - Human respiratory tract
KW - Mobile laboratory
KW - Traffic
KW - Ultrafine particles
U2 - 10.1016/j.envres.2023.116068
DO - 10.1016/j.envres.2023.116068
M3 - Article
AN - SCOPUS:85156118032
SN - 0013-9351
VL - 231
JO - Environmental Research
JF - Environmental Research
M1 - 116068
ER -
