The spatial variation of O3, NO, NO2 and NO x and the relation between them in two Swedish cities

Abstract

Ozone and nitrogen oxides (NOx) are air pollutants with known associations to adverse health effects on humans. Few studies have simultaneously measured ozone and nitrogen oxides with high spatial resolution. The main aim of this paper was to assess the levels and variation of ground-level ozone, NO2 and NOx in two Swedish cities. An additional aim was to describe the levels of these pollutants within and between three different types of measurement sites (regional background, urban background and traffic sites) and within and between different measurement periods of the year. Three weekly sampling campaigns of NOx and ozone were conducted simultaneously at 20 sites in two Swedish regions using Ogawa badges. Ozone was measured at 20 additional sites in each area. The median ozone concentration for all measurements was statistically significantly higher in Malmö (67 μg/m3) compared to Umeå (56 μg/m3), and in both cities, ozone levels were highest in April. Measurement period was a more important factor for describing the variation in ozone concentrations than the type of measurement site. The levels of NO2 and NOx were statistically significantly higher in the Malmö area (8.1 and 12 μg/m3) compared to the Umeå area (4.5 and 8.9 μg/m3). The levels were generally highest at the sites categorized as traffic, while the variability between different seasons was sparse.Electronic supplementary materialThe online version of this article (doi:10.1007/s10661-017-5872-z) contains supplementary material, which is available to authorized users.

Contributions of different anthropogenic volatile organic compound sources to ozone formation at a receptor site in the Pearl River Delta region and its policy implications

“…Factor 2 was characterized by high percentages of C 6 -C 7 alkanes and certain amounts of aromatics, while the contributions of other combustion tracers were insignificant in this factor, suggesting that this factor was related to solvent usage. This is consistent with previous studies that show that aromatics and C 6 -C 7 alkanes could be used as solvents in the printing and paint industry (He et al, 2002;Chan et al, 2006;Liu et al, 2008a, b); 18 ± 2 % of the observed VOCs were identified to be associated with solvent use. Factor 3 was represented by high percentages of ethane (∼ 65 %), acetylene (∼ 51 %), benzene (∼ 52 %) and ethene (∼ 31 %), together with some C 3 -C 5 alkanes and alkenes, which are typically tracers of incomplete combustion such as vehicular exhaust and biomass burning (Nelson et al, 1984;Wadden et al, 1986;Blake et al, 1994;Rudolph, 1995;Guo et al, 2011a, b).…”

Mutual Information Input Selector and Probabilistic Machine Learning Utilisation for Air Pollution Proxies

“…From the MI scores, the variables that share the highest correlation to O 3 are NOx, wind speed (WS), m,p-Xylene (TNX) and NO 2 . It is well known from previous studies [20,58,59] that O 3 is strongly connected to NO and NO 2 as well as NOx concentrations. Furthermore, TNX was found as the largest contributor to O 3 formation [55].…”

A pilot study of gaseous pollutants' measurement (NO<sub>2</sub>, SO<sub>2</sub>, NH<sub>3</sub>, HNO<sub>3</sub> and O<sub>3</sub>) in Abidjan, Côte d'Ivoire: contribution to an overview of gaseous pollution in African cities

“…O 3 is often associated in urban areas with adverse effects on human health and natural environment (Hagenbjörk et al, 2017). It is well known that this secondary pollutant depends on photochemical interactions of gaseous precursors composed of nitrogen oxides (NO x ) and volatile organic compounds (VOCs) (Duan et al, 2008;WHO, 2006).…”

“…It is well known that this secondary pollutant depends on photochemical interactions of gaseous precursors composed of nitrogen oxides (NO x ) and volatile organic compounds (VOCs) (Duan et al, 2008;WHO, 2006). At a specific location, the level of O 3 concentration depends on emission of its precursors (VOCs and NO x ), the long-range transport of O 3 and meteorological parameters (Hagenbjörk et al, 2017). Two chemical regimes are associated with the rate of ozone production, the NO x -saturated (or VOC-limited) regime and the NO x -limited regime.…”