Effects of emission sources on the particle number size distribution of ambient air in the residential area

Particle size distribution is a major factor in the health and climate effects of ambient aerosols, it shows large variation depending on prevailing atmospheric emission sources. In this work, particle number distributions air were investigated at suburban detached housing area northern Helsinki, Finland, during half-year period from winter to summer 2020. The measurements conducted with scanning mobility sizer (SMPS) range 16–698 nm (mobility diameter), events dominant source identified systematically data based time day different physical chemical properties. During measurement period, four types contribution either wood-burning (WB), traffic (TRA), secondary biogenic (BIO), or long-range transported (LRT) aerosol observed. was largest for LRT followed by BIO, WB, TRA geometric mean diameters 72, 62, 57, 41 nm, respectively. BIO produced mode sizes modes 69, 46, 25 Each event type had also noticeably shape average (NSD). addition evaluation NSDs representing sources, COVID-19 lockdown specific properties studied as restrictions took place greatly reducing volumes Helsinki spring These significant concentrations NOx black carbon originating fossil fuel combustion concentration, but insignificant other variables such concentration mass (PM1, PM2.5, PM10).