INVESTIGATION OF ENVIRONMENTAL AIR POLLUTION AND ITS CHANGE ASSESSMENT IN ŠIAULIAI
Air pollution is one of the main reasons of pulmonary diseases, malignant tumours, allergic and other chronic deceases. In 2003, with the help of a mobile laboratory, investigation on air pollution and its distribution in Šiauliai city environment was accomplished. Measurements were performed once a month in exploratory positions deployed at 1 km intervals one from another. Average onetime annual pollutant concentration was measured, estimating one square kilometer. Concentration of CO in Šiauliai surroundings varied from 0,5 mg/m3 to 5,8 mg/m3 or by 51 % of Šiauliai area varied from 0,8 mg/m3 to 1,4 mg/m3. Concentration of NO2varied from 0,005 mg/m3 to 0,84 mg/m3 or by 57 % of the city area it varied from 0,010 mg/m3 to 0,020 mg/m3. Concentration of NO varied from 0,003 mg/m3 to 0,495 mg/m3. Concentration of SO2 varied from 0,0015 mg/m3 to 0,012 mg/m3. Concentration of O3 varied from 0,022 mg/m3 to 0,134 mg/m3. The total concentration of hydrocarbons varied from 1,5 ppm to 3,5 ppm. The highest level of pollution was observed in the central part of the city.