Investigation of NO2 Behaviour in the Temperate Continental Climate Road Environment

Abstract

During an extended period from 2010-2012 ambient air quality researches, concentration of nitrogen dioxide (NO 2 ) in the air was measured applying the passive method. In order to evaluate the spatial distribution of pollutants and the major sources, 12 sampling sites across the region were chosen. Additionally, the seasonal changes of this pollutant under different meteorological conditions (air temperature, humidity, wind speed and direction) were investigated. The long-term study showed 3.8 times higher NO 2 concentrations in the Mažeikiai urban area (24.2 μg m −3 ) as compared to other locations in the region (6.3 μg m −3 ). This confirms the assumption that the main source of NO 2 in this area is motor vehicle exhaust fumes. The analysis of the results obtained in different seasons showed a significant difference (p<0.05) in NO 2 concentrations under different meteorological conditions. The increase in NO 2 concentrations was recorded in the winter and late autumn seasons, due to reduced solar radiation and lower temperatures. Cluster analysis results showed that sampling sites can be grouped into different classes based on NO 2 main source, motor vehicles and traffic intensity.

Spatial and Temporal Variation in Ozone and Nitrogen Dioxide in the Seaside Recreation Area Environment

“…7). The correlation coeffi cient calculated between nitrogen dioxide concentration and traffi c intensity is 0.98 [3].…”

“…Such a distribution of ozone concentration in Klaipėda could be determined by the fact that this site is close to the road where traffi c is more intensive. It is known that traffi c is the main source of nitrogen dioxide [3]. This signifi cant increase of ozone in the Curonian Spit could be attributed to the decrease of NO x emissions, particularly NO.…”

“…The major part of inorganic pollutants is emitted to air from the energy and industrial sectors as well as vehicles [1,2]. In the largest cities of Lithuania, motor vehicles generate up to 80% of all pollutants emitted to the atmosphere; the major part of these pollutants is nitrogen oxides (NO x ) [3]. The highest one-hour NO 2 concentration in the places where traffi c is the most intensive in Lithuania is up to 170 μg/m 3 [4].…”

“…In the largest cities of Lithuania, motor vehicles generate up to 80% of all pollutants emitted to the atmosphere; the major part of these pollutants is nitrogen oxides (NO x ) [3]. The highest one-hour NO 2 concentration in the places where traffi c is the most intensive in Lithuania is up to 170 μg/m 3 [4]. Collections of nitrogen compounds have became one of the most serious ecological problems causing negative local, regional, and global processes [5].…”