DETERMINATION OF CORRELATION RELATIONSHIPS BETWEEN CONCENTRATIONS OFNITROGEN-CONTAINING GASEOUS COMPOUNDS AND MICRO DISPERSED PARTICLES IN THEURBAN ATMOSPHERE

The most environmentally hazardous micro particles PM2.5 and PM10 can enter the atmosphere directly from emission sources (primary particles) or form in the atmosphere as a result of chemical transformations of gases (secondary particles), such as sulphur dioxide, nitrogen oxides, ammonium compounds and some organic compounds. Thus, excessive anthropogenic nitrogen emissions into the environment can directly harm ecosystems by creating critical loads for eutrophication, contribute to negative climate change and also increase the level of environmental hazard of atmospheric air. The aim of the study is to quantitatively assess the pollution of atmospheric air in Kharkiv with environmentally hazardous micro particles and its correlation with the concentration of various nitrogen-containing compounds in the atmosphere. The concentration of micro particles PM10, PM2.5 and gaseous substances NH3 and NO2 in the atmosphere of two districts of Kharkiv (Nemyshdyansky and Osnovyansky) was measured on the Ecocity weather website four times a day in February and March 2025. The results of the data analysis showed a positive correlation between the concentrations of PM2.5 and PM10, a positive correlation between NH3 and PM10 and PM2.5 concentrations, as well as a negative correlation between NH3 and NO2 concentrations and a negative correlation between NO2 concentration and PM2.5 and PM10 concentrations. Moreover, the concentration of NH3 in the atmospheric air of the Osnovyanskyi district exceeded this indicator in the Nemyshdyanskyi district by almost an order of magnitude and sometimes reached environmentally hazardous levels. Individual exceedances of environmentally safe levels (according to EU standards) of micro particulate matter concentrations in the atmospheric air of these districts were also noted. Statistical analysis, correlation analysis and regression analysis were used to process the data. Processing of the obtained data using mathematical statistics methods proved the statistical significance of the correlation coefficients (between PM10 and NO2 concentrations, PM10 and NH3 concentrations, NO2 and NH3 concentrations). The regression parameters were found using the least squares method with the help of a built-in function in Excel, and the adequacy of the obtained model to the initial data was checked using Fisher's method. Based on the analysis of the obtained data, it was concluded that in the atmospheric air of the studied areas of Kharkiv, among nitrogen-containing compounds, the concentration of NH3 contributed to the formation of high concentrations of micro particles PM2.5 and PM10.