News 8.9.2021

A study reveals high atmospheric particle concentrations during both local and long-range pollution episodes in recent years

According to a new study, high atmospheric particle concentrations are present in Helsinki during pollution episodes. Results suggest that more measures are still required to cope with atmospheric pollution, both locally and internationally.

A new study led by the Finnish Meteorological Institute (FMI) at a street canyon located in Helsinki, Finland, revealed significant increases in particulate matter (PM1 and PM2.5) during pollution episodes. This, despite the mitigation policies implemented in northern Europe during last decades. A large fraction of particulate matter (PM) consisted of inorganics during long-range-transport pollution episodes, while local episodes showed an increase in eBC and organics. Street dust also seemed to increase significantly in spring. However, a trend analysis revealed a decrease in black carbon from fossil fuel (BCFF), organics, and nitrate over the studied years.

The study was performed for 4.5 years (2015–2019) and involved highly time-resolved measurements using several online state-of-the-art instruments, such as an aerosol chemical speciation monitor (ACSM), a multi-angle absorption photometer (MAAP), a differential mobility particle sizer (DMPS), and an Aethalometer (AE).

Aerosol particles have potential adverse effects on climate and human health. A decrease in the contribution of PM from traffic is expected to occur due to stricter legislation and improvements on vehicle technologies. However, this study demonstrated that more measures are still required to cope with atmospheric pollution, both at local and European/international levels.

Further information:

Researcher Luis Barreira, Finnish Meteorological Institute,

Barreira, L. M. F., Helin, A., Aurela, M., Teinilä, K., Friman, M., Kangas, L., Niemi, J. V., Portin, H., Kousa, A., Pirjola, L., Rönkkö, T., Saarikoski, S., Timonen, H.: In-depth characterization of submicron particulate matter inter-annual variations at a street canyon site in northern Europe, Atmos. Chem. Phys., 21, 6297–6314,, 2021.

The scientific article available here

Science newsAir qualityParticulate matter