Mathematical modeling of the concentration values for main air pollutants in Craiova (Romania) between 2010 and 2011

The main purpose of this paper is to present the evolution of the concentration for four main air pollutants in Craiova city, during twelve month (i.e., by any kind of weather). The selected period was between July 1^st 2010 and June 30^th 2011, and the pollutants submitted to the investigation were: nitrogen oxides NO_x, sulfur dioxide SO₂, carbon monoxide CO and suspended particulate matter, PM₁₀. Within the paper, two purposes are achieved. The most important one is presenting the data about the evolution of the concentration of the four pollutants taken into study, graphics being used to show the situation of air quality in Craiova during the selected period. Another purpose was to find a statistical model to fit the recorded data for PM₁₀, which is the log-normal distribution (the paper also presents some theoretical features of the model).