Ambient air quality in a low income urban area on the South African highveld: a case study of Leandra Township
Air pollution in residential areas is a problem in South Africa. The connection of low income households to the national electricity grid is perceived as one of the strategic measures taken by the government to solve the issue. In Leandra/Lebohang, a low income residential area on the Highveld, 1034 households were provided with electricity in 2001. Ambient PM10 and SO2 concentrations monitored in Leandra show that the electrification resulted in a significant reduction in PM10 concentrations particularly during the morning and evening peaks. There was also somewhat of a reduction in SO2 concentrations, although a non-local, probably industrial source, also contributes to SO2 levels in Leandra. PM10 and SO2 concentrations increased steadily again after the electrification, as the township expanded and the domestic use of coal increased. Annual PM10 concentrations were above the national annual limit (50 μg/m3) for all years during the 1999-2005 monitoring period except during 2001 and 2002. The number of exceedances of the PM10 daily limit was as high as 141 in 2000 and dropped to 0 in 2001. The SO2 annual national limit (19 ppb) was never exceeded during the 1999-2008 monitoring period. However, SO2 daily average national standard (48 ppb) was exceeded several times at Leandra with up to twelve exceedences measured in 2000. Effectively, electricity use reduces domestic emissions in low income residential areas by replacing coal and other dirtier fuels used for cooking and space heating and improve ambient air quality.