TITLE:
Evaluation of Ambient NO2 and SO2 Concentrations at Lephalale, Polokwane, and Steelpoort Area in the Limpopo Province of South Africa
AUTHORS:
Collet Maswanganyi, James Tshilongo, Andile Mkhohlakali, Lynwill Martin
KEYWORDS:
Seasonal Monitoring, SO2, NO2, Meteorological Parameters
JOURNAL NAME:
Open Journal of Air Pollution,
Vol.13 No.4,
November
25,
2024
ABSTRACT: Sulfur dioxide (SO2) and nitrogen dioxide (NO2) are some of the air pollutants in industrial and urban areas. These are the most prevalent inorganic pollutants that are a serious risk to public health in populated areas. However, Lephalale, Polokwane and Steelpoort have not received enough attention to date. Therefore, this study investigated seasonal levels of NO2 and SO2 concentrations using passive sampling during summer, winter, autumn and spring of 2021. The sampling was done the first seven days of the month. The relationship of inorganic pollutants with meteorological factors was performed statistically using multiple linear regression model. Lephalale exhibited the highest NO2 concentration, 1.74 µg/m3, in spring. Whereas Polokwane and Steelpoort peaked at 1.57 µg/m3 and 0.84 µg/m3 in winter, respectively. The concentrations of SO2 were higher in winter than in other seasons in all areas. The multiple linear regression models showed that NO2 and SO2 dispersion was influenced by meteorological parameters such as temperature, wind speed and relative humidity. In Polokwane and Steelpoort, NO2 and SO2 concentrations are inversely correlated to temperature and relative humidity. Similarly, NO2 concentrations are inversely correlated, while SO2 concentrations are directly correlated to both temperature and relative humidity in Lephalale. Wind speed had positive and inverse correlations to the concentrations of both air pollutants. The SO2 and NO2 concentrations did not exceed the annual average of 50 µg/m3 and 94 µg/m3 as set by National Ambient Air Quality Standards and World Health Organization. However, it is important to keep pollution concentrations of SO2 and NO2 to relatively safe for humans and the environment in the studied areas.