Modeling the drivers of urban fine PM pollution over Central Europe: contributions and impacts of emissions from different sources

Air pollution represents the most significant environmental health risk in Europe, which significantly impacts the health of the European population, especially in urban areas. The pollutants with the most critical threat to human health in European urban areas include fine particulate matter (PM), a mixture of aerosols with an aerodynamic diameter less or equal to 2.5 μm. To better understand the composition of fine PM in any urban area of Europe, it is important to identify and quantify the sources of its components. Such knowledge can be further used to propose effective strategies for reducing this type of pollution in this urban area. One of the commonly used ways to source attribution analysis of fine PM is to use sophisticated chemical transport models that can rigorously control: (1) the evolution of primary fine PM, (2) the formation of secondary inorganic and organic fine PM from gaseous precursors and their subsequent development, and (3) aqueous aerosol chemistry (e.i., all relevant processes connected with fine PM).

 

In this work, we utilized an offline coupled modeling framework consisting of the Weather Research and Forecast (WRF) Model version 4.0.3 and the Comprehensive Air quality Model with Extensions (CAMx) version 7.10 on the Central European domain with a horizontal resolution of 9 km for the period covering the years 2018 and 2019 to investigate the relationships between emissions from a wide range of anthropogenic activity sectors and the total concentrations of fine PM in six large cities of this region (Berlin, Munich, Prague, Vienna, Budapest, and Warsaw) from two different approaches. First, we analyzed the contributions of emissions from anthropogenic activity sectors to the total concentrations of fine PM using the Particulate Source Apportionment Technology (PSAT) tool implemented in the used version of the CAMx model. Second, using the zero-out method, we examined the impacts of emissions from the same anthropogenic activity sectors used in the source apportionment analysis on the total concentrations of fine PM. In this case, we additionally considered a dual implementation of organic aerosol chemistry/partitioning in the CAMx model by performing two sensitivity studies determining the impacts described above, each using one of the implementations. As part of the analysis, we compared the identified contributions with the impacts and discussed cases of mutual similarity between the two approaches.