Abstract:
Cardiovascular disease (CVD) is the top cause of mortality and a main contributor to
disability globally. The evidence so far is varied on whether cold or heat modifies the CVD effects
of air pollution. Weather conditions and air pollution sources and levels are different in different
countries. Studies in low-and middle-income countries are lacking. Mortality data were obtained
from Statistics South Africa. Air pollution and meteorological data were obtained from the South
AfricanWeather Service. A time-stratified case–crossover epidemiological design was applied. The
association between air pollutants (PM10, NO2 and SO2) and CVD mortality was investigated using
conditional logistic regression models. Susceptibility by sex and age groups was investigated. In
total, 54,356 CVD deaths were included in the 10-year study. The daily PM10, NO2 and SO2 levels
exceeded the daily WHO guidelines on 463, 421 and 8 days of the 3652 days, respectively. Higher air
pollution risks were observed in this study compared to those reported in meta-analyses. In general,
the elderly and females seemed to be vulnerable to air pollutants, especially at high and moderate
apparent temperature levels. Harvesting effects were observed at longer lags. The results can be used
to develop an early warning system for the city.
Description:
DATA AVAILABILITY STATEMENT : Mortality data: individual-level respiratory disease mortality data
(International Classification of Disease, 10th version [ICD-10] (J00–J99) were obtained from Statistics
South Africa for the study period 1 January 2006 to 31 December 2015, but restrictions apply to the
availability of these data, which were used under a strict signed data agreement, and so are not
publicly available. Air pollution, temperature ( C) and relative humidity (%) data were obtained
from the South African Weather Service for the study period, after signing a data agreement.
