Sources and concentrations of acidic constituents in the ambient air of Saudi Arabia

Abstract

Air pollution has given great interest because of its wide adverse effects on the human health and all components of the ecosystem. In developing countries, research concerning assessment of acidic constituents of the ambient air and its effects is still lacking, particularly in the Arab ones. The objective of this study was to assess levels of acidic constituents of the ambient air in Saudi Arabia through selection of Dammam City as a case study. This study presents a comprehensive set of three successive academic years of data (2016–2019). Levels of PM10, SO2, and NO2 were continuously measured for 24 h/day. Concentrations of Cl−, SO42−, and NO3− and fly ash were determined by standard wet chemical methods. The mean concentrations of PM10 (177.4 ± 52.5 μg/m3) exceeded all the local and international standards, where levels of SO2 (17.5 ± 6.2 μg/m3) and NO2 (101.1 ± 27.3 μg/m3) were lower than their AQGs. The sum of the Cl−, SO42−, and NO3− constituted 29.2% of the PM10 concentration, while the fly ash constituted 55.1%. Dammam atmosphere is greatly affected by the combustion sources of industry and traffic activity rather than the formation of secondary aerosols as the result of chemical transformation of acidic gases (NO2 and SO2). In addition, acidic constituents of the ambient air are not a considerable environmental problem in Dammam City and Kingdom of Saudi Arabia as general.