Estimating the burden of disease attributable to urban outdoor air pollution in South Africa in 2000

Abstract

Objectives. To quantify the mortality burden attributed to urban outdoor air pollution in South Africa in 2000.
Design. The study followed comparative risk assessment (CRA) methodology developed by the World Heath Organization (WHO). In most urban areas, annual mean concentrations of particulate matter (PM) with diameters less than 10 μm (PM10) from monitoring network data and PM with diameters less than 2.5 μm (PM2.s) derived using a ratio method were weighted according to population size. PM10 and PM2.s data from air-quality assessment studies in areas not covered by the network were also included. Population-attributable fractions calculated using risk coefficients presented in the WHO study were weighted by the proportion of the total population (33%) in urban environments, and applied to revised estimates of deaths and years of life lost (YLLs) for South Africa in 2000.
Setting. South Africa.
Subjects. Children under 5 years and adults 30 years and older.
Outcome measures. Mortality and YLLs from lung cancer and cardiopulmonary disease in adults (30 years and older), and from acute respiratory infections (ARis) in children aged 0 - 4 years. 
Results. Outdoor air pollution in urban areas in South Africa was estimated to cause 3.7% of the national mortality from cardiopulmonary disease and 5.1 % of mortality attributable to cancers of the trachea, bronchus and lung in adults aged 30 years and older, and 1.1 % of mortality from ARis in children under 5 years of age. This amounts to 4 637 or 0.9% (95% uncertainty interval 0.3 - 1.5%) of all deaths and about 42 000 YLLs, or 0.4% (95% uncertainty interval 0.1 - 0.7%) of all YLLs in persons in South Africa in 2000. 
Conclusion. Urban air pollution has under-recognised public health impacts in South Africa. Fossil fuel combustion emissions and traffic-related air pollution remain key targets for public health in South Africa.