# Examining the Amount of Particulate Matter (PM) Emissions in Urban Areas
## 1 Introduction
The harmfulness of particulate matter to human health depends not only on the size of the particles but also on their composition, which is conditioned by what source they come from [22; 23]. In the studies of [PERSON] et al., the amount of concentration of particulate matter depending on the road surface is characterized. The research results show that in the rural urban landscape, the main source of PM\({}_{2.5}\) is automobile activity. Suspended particulate matter accounts for 89% and 75% of total PM\({}_{2.5}\) on rural and urban roads, respectively. The proportion is higher in rural areas due to the poor condition of roads. In addition, vehicles driving on rural roads contribute to emissions in a similar proportion to the length of rural roads. It seriously affects human health as well as the environment [24; 25]. Several studies have been conducted to investigate the state of PM pollution, which in most cases exceeds global air quality guidelines [26; 27]. Therefore, air quality has become an important measure of life quality in densely populated cities and industrial areas. Air quality control is currently highly desirable to improve the sustainability of cities and the quality of life of their inhabitants [28; 29]. Legislative air quality standards and emission control policies regulate the release of harmful substances into the atmosphere and manage the concentrations of air pollutants, such as PM\({}_{2.5}\), PM\({}_{10}\), NO\({}_{\mathsf{X}}\), and O\({}_{3}\)[30; 31]. However, it is necessary to monitor and forecast air quality for the effective prevention of air pollution. Several studies have been conducted that focus on different methodological strategies for effective PM concentration mapping [32; 33]. Several authors have addressed the relationship between the number of vehicles and PM concentration; however,they declared uneven results. Some researchers found that increases in traffic congestion in urban areas resulted in increasing PM levels [34; 35; 36], while others discovered very weak or zero [37; 38; 39; 40] correlation between variables. The COVID-19 pandemic also had an impact on improvements to air quality when there were mass restrictions on human activities, which led to changes in air pollution levels in many regions around the world [41; 42]. The research conducted was aimed at evaluating the relationship between the number and category of vehicles in relation to the concentration of particulate matter. The research points to different levels of pollution depending on the category and number of vehicles that were registered during the research. Currently, the Slovak Republic does not have a universal tool for monitoring air quality in urban areas. Within cities or larger agglomerations, there is no study available on how to monitor and evaluate air quality in a specific section. In the near future, it is planned to create measuring points in selected places that will continuously monitor air quality. One of the assessed values is the concentration of particulate matter. For this reason, the research is carried out in such a form. The results of the study can serve as a tool for the correct placement of measuring devices in order to permanently monitor air quality. Based on the results of measurements and current data, specific measures can be introduced (entry ban, limited entry for selected types of vehicles, etc.) with the aim of permanently reducing emissions in the urban environment. The research findings further provide support for planning the optimization of air quality management policies toward the creation of sustainable cities. In the Slovak Republic, there is still no instrument to prevent the movement of passenger traffic in the city center. To a large extent, the study could be beneficial in building a green policy and permanently reducing emissions due to traffic within cities. We evaluated data provided by the Slovak Hydrometeorological Institute, the only institution in the Slovak Republic that deals with monitoring and evaluating air quality.