Spatial and Temporal Variations in PM 10 Concentrations between 2010-2017 in South Africa.

Particulate matter less than or equal to 10 μm in aerodynamic diameter (PM 10 µg/m 3 ) is a priority air pollutant and one of the most widely monitored ambient air pollutants in South Africa. This study analyzed PM 10 from monitoring 44 sites across four provinces of South Africa (Gauteng, Mpumalanga, Western Cape and KwaZulu-Natal) and aimed to present spatial and temporal variation in the PM 10 concentration across the provinces. In addition, potential influencing factors of PM 10 variations around the three site categories (Residential, Industrial and Traffic) were explored. The spatial trend in daily PM 10 concentration variation shows PM 10 concentration can be 5.7 times higher than the revised 2021 World Health Organization annual PM 10 air quality guideline of 15 µg/m 3 in Gauteng province during the winter season. Temporally, the highest weekly PM 10 concentrations of 51.4 µg/m 3 , 46.8 µg/m 3 , 29.1 µg/m 3 and 25.1 µg/m 3 at Gauteng, Mpumalanga, KwaZulu-Natal and Western Cape Province were recorded during the weekdays. The study results suggest a decrease in the change of annual PM 10 levels at sites in Gauteng and Mpumalanga Provinces. An increased change in annual PM 10 levels was reported at most sites in Western Cape and KwaZulu-Natal.