Investigating PM_2.5 pollution patterns in South Africa using space-time analysis

Abstract

<abstract> <p>The global concentration of fine particulate matter (PM<sub>2.5</sub>) is experiencing an upward trend. This study investigates the utilization of space-time cubes to visualize and interpret PM<sub>2.5</sub> data in South Africa over multiple temporal intervals spanning from 1998 to 2022. The findings indicated that the mean PM<sub>2.5</sub> concentrations in Gauteng Province were the highest, with a value of 53 μg/m<sup>3</sup> in 2010, whereas the lowest mean PM<sub>2.5</sub> concentrations were seen in the Western Cape Province, with a value of 6.59 μg/m<sup>3</sup> in 1999. In 2010, there was a rise in the average concentration of PM<sub>2.5</sub> across all provinces. The increase might be attributed to South Africa being the host nation for the 2010 FIFA World Cup. In most provinces, there has been a general trend of decreasing PM<sub>2.5</sub> concentrations over the previous decade. Nevertheless, the issue of PM<sub>2.5</sub> remains a large reason for apprehension. The study also forecasts South Africa's PM<sub>2.5</sub> levels until 2029 using simple curve fitting, exponential smoothing and forest-based models. Spatial analysis revealed that different areas require distinct models for accurate forecasts. The complexity of PM<sub>2.5</sub> trends underscores the necessity for varied models and evaluation tools.</p> </abstract>