## 2 Materials and Methods
### Air Pollution Modeling and Emission Data  
The EMEP/MSC-W model version 4.10 [26] was used to calculate air pollution concentrations throughout Poland (EMEP4 PL). The model was originally developed at the  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Region** & **Scenario 1** & **Scenario 2** & **Scenario 3** \\ \hline Lower Silesia [\%] & 94.87 & 85.84 & 63.04 \\ Lodzkie province [\%] & 94.87 & 85.84 & 71.33 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Emission reduction of primary PM\({}_{2.5}\) results in the household sector in Lower Silesia and Lodzkie region.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Region** & **Before 1944** & **1945–1988** & **1989–2002** & **2003–2011 and under Construction** \\ \hline Lower Silesia [\%] & 60.6 & 14.2 & 6.3 & 12.2 \\ Lodzkie province [\%] & 11.1 & 64.7 & 10.6 & 8.1 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Percentage of buildings by the date of construction in Lower Silesia and Lodzkie region.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Region** & **Before 1944** & **1945–1988** & **1989–2002** & **2003–2011 and under Construction** \\ \hline Energy [kWh/m\({}^{2}\) annual] & 350 & 260 & 180 & 120 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Energy demand for heating a building depending on age.  
Norwegian Meteorological Institute as part of the Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe. It is a state-of-the-art Eulerian atmospheric chemistry transport model, which is applied to calculate concentrations of PM, O\({}_{3}\) and S and N deposition for Europe. The model was released as OpenSource code in 2008 and is under continuous development to meet new objectives within the EMEP programme and other projects. The model is fully flexible in the domain and resolution of its application. It has been successfully applied at a high resolution (5 km and 1 km) scale over the UK [27; 28; 29]. Details on the regional application of the EMEP/MSC-W model over Poland are given in [30].  
In this study, we used two one-way nested domains--the outer domain covers Europe on a 12 km \(\times\) 12 km grid (d01), and the inner domain is focused on Poland at a 4 km \(\times\) 4 km resolution (d02). The parent domain has 285 and 332 points in the west-east and south--north directions, respectively. The model is coupled offline with meteorology, and we used the Weather Research and Forecasting (WRF) model version 3.8.1 [31] to calculate meteorological conditions to EMEP4 PL [27]. The TNO MACC III emission database at 1/8\({}^{\circ}\)\(\times\) 1/16\({}^{\circ}\) spatial resolution [32] was applied for the outer domain and the national database (1 km \(\times\) 1 km) provided by the Chief Inspectorate of Environmental Protection was used for Poland in the inner domain.  
The scenarios with EMEP4 PL were run four times for the entire year 2015. The first scenario was run without any changes to the emission database; for the second, third and fourth runs, we used modified emission database. The particulate matter emissions for Lower Silesia and Lodzkie province were scaled by the emission factors described in the section above.