Background: The Vaal Triangle is an area generally associated with a number of
harmful determinants of health since it houses diverse industrial processes and
industrial development in South Africa, hence being categorised as an outdoor air
pollution priority area in 2006.
Method: A cross-sectional inter-comparative study to the 1990 Vaal Triangle Air
Pollution and Health Study (VAPS) was conducted in 2010. The main objectives of
this study were to measure the prevalence of upper and lower respiratory illnesses of
10-year-old children in 2010 and compare those findings to the 1990 study, and
lastly to identify risk and protective factors for respiratory illnesses in 1990 and in
2010. In addition, the association between exposure factors (risk and protective
factors) that are sources of indoor air pollution and factors related to diet and
household living conditions and their associations with upper and lower respiratory
health illnesses in 1990 and 2010 was determined.
Results and Discussion: The prevalence of the respiratory health outcomes in the
1990 study and 2010 study cannot be compared directly since a 1-year prevalence
was determined in 1990 and a 6-month prevalence in 2010. Throughout the
dissertation this should be kept in mind. The change in prevalence of a respiratory
health outcome observed in 1990 and in 2010 is just an indication of the possible
change. The 1990 1-year prevalence and the 2-week 2010 prevalence of asthma
were the same in the two study populations (i.e. 12%). The 6-month prevalence of
sinusitis, bronchitis and pneumonia in 2010 was lower when compared to the yearly
prevalence of these illnesses in the 1990 study. On completion of the multivariate
analyses, in 1990 study, the use of a gas heater acted as a risk factor for pneumonia
(a lower respiratory illness), with a odds ratio of 3.67 (1.15-11.71) and a p-value of
0.03, whilst environmental tobacco smoke within the household was protective of
hay fever and sinusitis (upper respiratory illnesses). In the 2010 study, the
consumption of chicken and/or fish and fruit at least three times a week was
protective of bronchitis (with odds ratios of 0.23 and 0.26 respectively).
Conclusion and Recommendations: It is not certain whether the change in the
respiratory health status of 10-year-olds living in the Vaal Triangle is real as the
prevalence of health outcomes in the two studies cannot be compared directly to one
another due to the differences in prevalence time periods in the two studies.
Nevertheless, a statistically significant change was observed in the prevalence of
sinusitis, earache, bronchitis, and pneumonia between the two study populations. It
is imperative to have a study protocol; this ensures all levels of measure are consistent in both studies and leads to a dataset of high quality. There is also a need
for more analytical epidemiological studies (i.e. cohort, time-series, case-crossover
and panel studies) to be done in South Africa, addressing indoor and outdoor air
pollution and respiratory health.