Feig, Gregor TimothyGarland, Rebecca M.Naidoo, SenecaMaluleke, AmukelaniVan der Merwe, Marna2020-05-192020-05-192019Feig, G., Garland, R.M., Naidoo, S. et al. 2019, 'Assessment of changes in concentrations of selected criteria pollutants in the Vaal and Highveld priority areas', Clean Air Journal, vol. 29, no. 2, pp. 1-13.2410-972X10.17159/caj/2019/29/2.7464http://hdl.handle.net/2263/74629Ambient air pollution has important impacts on a variety of environmental issues, particularly on human health and ecosystem processes. A key tool for understanding the impacts of atmospheric pollution is through the long-term measurement of the ambient concentrations of criteria atmospheric pollutants. Monitoring of ambient pollution concentrations has been conducted in two of the National Air Quality Priority Areas since 2007. During this time period, significant changes in the management of air pollution have occurred, including the adoption of the ambient air quality standards, and the implementation of Section 21 emission standards. This paper examines the long-term evolution of ambient concentrations for PM and SO2 in the Vaal Triangle Airshed Priority Area and Highveld Priority Area. These trends will be evaluated against the implementation of management interventions and the variation in the measured concentrations and emerging areas of concern are highlighted.en© 2019. The Author(s). Published under a Creative Commons Attribution Licence.Particulate matter (PM)SO2Priority areasAir quality trendsVaal triangle priority areaHighveld priority areaTheil-SenArticle