High Contribution of Biomass Combustion to PM2.5 in the City Centre of Naples (Italy)

Atmosphere

Katrin Zenker¹  HarroA.J. Meijer¹  Haiyan Ni¹  Ulrike Dusek¹  Antonio D’Onofrio²  Carmina Sirignano²  Elena Chianese³  Angelo Riccio³ 

[1] Centre for Isotope Research (CIO) Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen, 9747 AG Groningen, The Netherlands;Department of Mathematics and Physics, Centre for Isotope Research on Cultural and Environmental heritage (CIRCE), Università degli Studi della Campania Luigi Vanvitelli, 81100 Caserta, Italy;Department of Science and Technology, Parthenope University of Naples, 80143 Napoli, Italy;

关键词: PM_2.5;    EC;    OC;    ¹⁴C;    urban air quality;    source apportionment;   

DOI  :  10.3390/atmos10080451

来源: DOAJ

【 摘 要 】

A better knowledge of the local and regional sources of the atmospheric particulate matter provides policy makers with the proper awareness when acting to improve air quality, in order to protect public health. A source apportionment study of the carbonaceous aerosol in Naples (Italy) is presented here, in order to improve this understanding in a vulnerable urban area. The aim of this study is quantifying directly fossil and non-fossil contributions to carbonaceous aerosol, by means of radiocarbon measurements. This is the first time that such an approach is implemented in this area. Fine particles with diameter ≤ 2.5 µm (PM_2.5) were collected daily on top of a building in the city center, from November 2016 until January 2017. The carbonaceous aerosol was separated into organic carbon (OC) and elemental carbon (EC), by a two-step thermal desorption method. Subsequent radiocarbon analysis enabled the partitioning of the major sources of carbonaceous aerosol into fossil and non-fossil ones by applying radiocarbon isotopic mass balance. The PM_2.5 concentration was on average 29 ± 3 µg⁄m³ (mean ± standard error; n = 18), with a maximum of 68.6 ± 0.7 µg⁄m³ on a day when air masses back-trajectories suggest a local origin and stagnant airflow conditions in the region. The carbonaceous component accounts for roughly half of the PM_2.5 mass. Fossil fuel emissions are a minor source of OC (23%), but the dominant source of EC (66%), which is directly emitted during combustion processes. However, overall only 30% of the total carbon is of fossil origin, accounting for 14% of PM_2.5 mass. Surprisingly, a comparable contribution is due to primary biomass burning carbon, which accounts in total for 15% of PM_2.5 mass. Traffic pollution, the main cause of fossil fuel emissions in urban areas, is a significant, but not the predominant source of carbonaceous particle concentration. These findings support the conclusion of a predominant contribution from non-fossil sources to the carbon in airborne particulate matter, which policy makers should take into account when planning mitigation strategies to improve urban air quality.

【 授权许可】

Unknown