Air pollutant concentrations

About: Air pollutant concentrations is a research topic. Over the lifetime, 1652 publications have been published within this topic receiving 36138 citations.

Impact of the Transboundary Transport of Air Pollutants on Air Quality in Spain

Abstract: Although compliance with the European limit values for air pollutants has been achieved over large parts in Spain, some challenges remain for O3 on the maximum daily 8-hour mean and information limit values, for particulate matter on the PM10 annual and daily limit values and for NO2 on annual and hourly limit values. Transboundary transport of air pollutants has started to be recognized as a mechanism affecting air quality. Nevertheless, as a consequence of the complexity of atmospheric chemistry it is not easy to determine the importance of this effect. Photochemical models constitute an adequate tool to address this challenge, allowing the identification of pollutant pathways and the quantifi- cation of the influence of long-range transport of air pollutants. In this paper we evaluate the influence of out-of-Spain emissions on this non-compliance picture by using the CHIMERE photochemical model. For this purpose the model was run at a 0.2?-horizontal resolution for a European domain. Although at this resolution not all the local effects can be captured, transboundary transport of air pollutants can be examined. Several simulations were performed considering different emission scenarios. To see all out-of-Spain emissions influence, all the emissions were set to zero, excepting those in Spain. This includes examining European and ships effects on air quality in Spain. A second simulation was performed setting to zero just European-countries emissions, to see the effect of Europe. The third and fourth simulations were carried out by setting to zero France and Portugal emissions respectively. Ozone has been found to be the pollutant more affected by this transboundary transport, in particular in the summer period. The model indicates that the incoming air masses contributed in 2009 to the non-compliance with the European normative regulating the maximum daily 8-hour mean.

Temporal distribution, influencing factors and pollution sources of urban ambient air quality in Nanchong, China

Abstract: The PM10, SO₂ and NO₂ mass concentrations were obtained over five years from monitoring stations across Nanchong, a southwest city in China. Changes in urban air quality over time, as well as the factors influencing that change, were evaluated based on air pollutant concentrations, the Air Pollution Index (API), and the Comprehensive Pollution Index (P). The results showed that the total annual mean PM10, SO₂ and NO₂ concentrations over the five years studied were 61.1±1.1, 45.0±3.9 and 34.9±4.9 μg·m-3, respectively. The annual mean concentrations displayed a generally decreasing trend; lower than the annual mean second-level air quality limit. Meanwhile, the annual mean API values were in a small range of 52-53, the air quality levels were gradeⅡ, and P values were 1.06-1.21 less than the slight level (P ≤ 1.31). Total monthly mean PM10, SO₂, NO₂ concentrations, and API and P values were consistently higher in winter and spring than during autumn and summer. The results of a correlation analysis showed that temperature and pressure were the major meteorological factors influencing pollution levels. Pollution sources included industrial coal and straw burning, automobiles exhaust and road dust, fireworks, and dust storms.