Short-Term Effects of PM; 10; , NO; 2; , SO; 2; and O; 3; on Cardio-Respiratory Mortality in Cape Town, South Africa, 2006-2015

The health effect of air pollution is rarely quantified in Africa, and this is evident in global systematic reviews and multi-city studies which only includes South Africa.; A time-series analysis was conducted on daily mortality (cardiovascular (CVD) and respiratory diseases (RD)) and air pollution from 2006-2015 for the city of Cape Town. We fitted single- and multi-pollutant models to test the independent effects of particulate matter (PM; 10; ), nitrogen dioxide (NO; 2; ), sulphur dioxide (SO; 2; ) and ozone (O; 3; ) from co-pollutants.; daily average concentrations per interquartile range (IQR) increase of 16.4 µg/m; 3; PM; 10; , 10.7 µg/m; 3; NO; 2; , 6 µg/m; 3; SO; 2; and 15.6 µg/m; 3; O; 3; lag 0-1 were positively associated with CVD, with an increased risk of 2.4% (95% CI: 0.9-3.9%), 2.2 (95% CI: 0.4-4.1%), 1.4% (95% CI: 0-2.8%) and 2.5% (95% CI: 0.2-4.8%), respectively. For RD, only NO; 2; showed a significant positive association with a 4.5% (95% CI: 1.4-7.6%) increase per IQR. In multi-pollutant models, associations of NO; 2; with RD remained unchanged when adjusted for PM; 10; and SO; 2; but was weakened for O; 3; . In CVD, O; 3; estimates were insensitive to other pollutants showing an increased risk. Interestingly, CVD and RD lag structures of PM; 10; , showed significant acute effect with evidence of mortality displacement.; The findings suggest that air pollution is associated with mortality, and exposure to PM; 10; advances the death of frail population.