GAW Report No. 205 - IGAC Project

CHAPTER 2 - AFRICAdistinct diurnal trend. Within coal burning townships, levels of TSP were 4-6 times worsethan regional averages.• Sulphur dioxide levels were found to exceed air quality guidelines less than 5% of the timein the Sasolburg industrial area, with SO 2 levels in residential areas being below air qualityguidelines. Concentration peaks observed during the early morning are associated withemissions from tall stacks in the region.• No exceedances of ambient air quality guidelines for NO X were observed to occur duringVAPS. An increase in annual averages occurred during the 1990 to 1993 period, withincreasing NO X concentrations at the Sasolburg Industrial site.A similar pattern was observed 10 years later.More recent data are now available in the Vaal Triangle area, in connection with Sasoland Eskom monitoring sites. Also new measurements are being developed in the frame of theGRDI ARSAIO programme, a collaboration between North-West University (South Africa) andLaboratoire d’Aérologie (France). Efforts will focus on aerosol chemical speciation and biologicalimpacts on human health in the Vaal triangle. An example of expected results is shown in Figure15. Aerosol chemical speciation was obtained during the 2006 winter months for PM2.5 and PM10particles at the Amersfoot rural site, which has an industrial influence (IDAF/DEBITS network,http://idaf.sedoo.fr). The data show high relative contribution of organic carbon particles followedby sulphate and black carbon. Corresponding results obtained from a modelling study are addedfor comparison.Figure 15 - Modelled/Measured size speciated aerosol chemistry at the Amersfoort site for the 2005-2007 period[K. Martin, PhD 2008; Guillaume et al., 2007]Finally, as previously indicated, this review shows that air quality is a national concern andair quality national legislation is becoming more and more stringent. The National EnvironmentalManagement (Air Quality Act, Act No. 39, 2004, 2010) is now replacing the Atmospheric PollutionPrevention Act (APPA), Act 45 of 1965. In 2010, national ambient air quality standards have beendefined for SO 2 , NO 2 , PM10, 0 3 , benzene, lead, CO (http://www.naca.org.za) with addition ofPM2.5 in September 2012. Note that a recent workshop in 2011 “Changing Chemistry in aChanging Climate: Human and Natural Impacts over southern Africa – C4-SAR” organized byBurrows, Piketh and Thompson also gathered many studies here mentioned.2.3.4 HealthMany epidemiological studies related to indoor and outdoor air pollution have beenconducted in South Africa since 20 years, using different indicators (mortality rate, risk assessmentstudies, health index…). A few of them (this is not an exhaustive list), is now presented tounderline the evidence of air pollution impacts.General studies in South AfricaThe mortality rate of acute respiratory infections (ARI) in South Africa is reported to be 270times greater than for children in Western Europe [Terblanche et al., 1993]. Recent47