Traffic is a major source of atmospheric nanocluster aerosol
Rönkkö, Topi; Kuuluvainen, Heino; Karjalainen, Panu; Keskinen, Jorma; Hillamo, Risto; Niemi, Jarkko V.; Pirjola, Liisa; Timonen, Hilkka J.; Saarikoski, Sanna; Saukko, Erkka; Järvinen, Anssi; Silvennoinen, Henna; Rostedt, Antti; Olin, Miska; Yli-Ojanperä, Jaakko; Nousiainen, Pekka; Kousa, Anu; Dal Maso, Miikka (2017-07-18)
Rönkkö, Topi
Kuuluvainen, Heino
Karjalainen, Panu
Keskinen, Jorma
Hillamo, Risto
Niemi, Jarkko V.
Pirjola, Liisa
Timonen, Hilkka J.
Saarikoski, Sanna
Saukko, Erkka
Järvinen, Anssi
Silvennoinen, Henna
Rostedt, Antti
Olin, Miska
Yli-Ojanperä, Jaakko
Nousiainen, Pekka
Kousa, Anu
Dal Maso, Miikka
18.07.2017
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201712192416
https://urn.fi/URN:NBN:fi:tty-201712192416
Kuvaus
Peer reviewed
Tiivistelmä
In densely populated areas, traffic is a significant source of atmospheric aerosol particles. Owing to their small size and complicated chemical and physical characteristics, atmospheric particles resulting from traffic emissions pose a significant risk to human health and also contribute to anthropogenic forcing of climate. Previous research has established that vehicles directly emit primary aerosol particles and also contribute to secondary aerosol particle formation by emitting aerosol precursors. Here, we extend the urban atmospheric aerosol characterization to cover nanocluster aerosol (NCA) particles and show that a major fraction of particles emitted by road transportation are in a previously unmeasured size range of 1.3–3.0 nm. For instance, in a semiurban roadside environment, the NCA represented 20–54% of the total particle concentration in ambient air. The observed NCA concentrations varied significantly depending on the traffic rate and wind direction. The emission factors of NCA for traffic were 2.4·1015 (kgfuel)−1 in a roadside environment, 2.6·1015 (kgfuel)−1 in a street canyon, and 2.9·1015 (kgfuel)−1 in an on-road study throughout Europe. Interestingly, these emissions were not associated with all vehicles. In engine laboratory experiments, the emission factor of exhaust NCA varied from a relatively low value of 1.6·1012 (kgfuel)−1 to a high value of 4.3·1015 (kgfuel)−1. These NCA emissions directly affect particle concentrations and human exposure to nanosized aerosol in urban areas, and potentially may act as nanosized condensation nuclei for the condensation of atmospheric low-volatile organic compounds.
Kokoelmat
- TUNICRIS-julkaisut [16929]