Atmospheric black carbon in Helsinki

• Published in: Atmospheric environment (1994) Vol. 34; no. 9; pp. 1497 - 1506
• Main Authors: Pakkanen, Tuomo A, Kerminen, Veli-Matti, Ojanen, Christina H, Hillamo, Risto E, Aarnio, Päivi, Koskentalo, Tarja
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2000; Elsevier Science
• Subjects: Applied sciences; Atmosphere; Atmospheric pollution; Background; Black carbon; City; Exact sciences and technology; Finland, Helsinki; Indoor pollution and occupational exposure; Pollution; Sources; Traffic; Europe; Finland; Helsinki, Finland; City; Background; Black carbon; Sources; Atmosphere; Traffic; Carbon black; Air quality; Daily variation; Urban area; Diurnal variation; Time variation; Suspended particle; Surveillance; Fine particle; Content; Aerosols; Pollution source inventory; Air pollution
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/S1352-2310(99)00344-1

Atmospheric fine particle black carbon (BC) was measured close to downtown of Helsinki, during November 1996–June 1997. The average BC concentrations were 1.5 μg m −3 for working days, 1.2 μg m −3 for Saturdays, and about 1 μg m −3 for Sundays and public holidays. The overall average BC concentration was equal to 1.38 μg m −3 and its average contribution to fine particle mass equal to 19%. On working days BC concentrations showed a clear diurnal variation with the highest hourly average values occurring during the morning (2.7 μg m −3) and evening (1.9 μg m −3) rush hours. Contribution of the long-range transport to the BC was estimated to be on average about 0.4 μg m −3, which is believed to represent the average regional background over southern Finland. However, this transport was very different from different geographical regions: from the densely populated areas of East- and Central-Europe it was about 0.8 μg m −3, while in northerly and northwesterly air masses it was only about 0.15 μg m −3. Local traffic was by far the most important local BC source contributing about 63, 54 and 44% on working days, Saturdays and Sundays, respectively. Other local sources were largely masked by the traffic and their contribution was estimated roughly to be of the order of 10%. The rest of BC was attributed to long-range transport.