symptoms in schoolchildren in the environs of a petrochemical refinery: a
cross-sectional study.
Environ Health. 2009 Sep 25;8(1):45. [Epub ahead of print
White N, Tewaternaude J, van der Walt A, Ravenscroft G, Roberts W, Ehrlich
R.'
ABSTRACT:
BACKGROUND: Community concern about asthma prompted an epidemiological study
of children living near a petrochemical refinery in Cape Town, South Africa.
Because of resource constraints and the complexity of refinery emissions,
neither direct environmental measurements nor modelling of airborne
pollutants was possible. Instead a meteorologically derived exposure metric
was calculated with the refinery as the putative point source. The study
aimed to determine whether (1) asthma symptom prevalences were elevated
compared to comparable areas in Cape Town and (2) whether there was an
association between asthma symptom prevalences and the derived exposure
metric.
METHODS: A cross-sectional study was carried out of all consenting school
children aged 11 to 14 years attending schools in a defined area, utilizing
the International Study of Asthma and Allergy in Childhood (ISAAC) written
and video questionnaires. Information was collected on potential
confounders, e.g. parental history of atopic disease, active and passive
smoking by the participant, birth order, number of children in the home and
distance from a major road. The exposure metric combined residential
distance of each child from the refinery with a wind vector in the form of
wind speed, wind direction and proportion of the year blown.
RESULTS: A total of 2,361 children from 17 schools met the criteria for
inclusion. In multivariate analysis, meteorologically estimated exposure
(MEE), but not simple distance from the refinery, was positively associated
with having to take an inhaler to school [odds ratio per interquartile range
(OR) 1.22, 95% confidence interval (CI) 1.06 - 1.40], and with a number of
video elicited asthma symptoms, including recent waking with wheezing (OR
1.33, 95% CI 1.06-1.66) and frequent wheezing at rest (OR 1.27, 95% CI
1.05 - 1.54). Symptom prevalences were higher than in other areas of the
city, with frequent waking with wheezing being in great excess (OR 8.92, 95%
CI 4.79-16.63).
CONCLUSIONS: The results support the hypothesis of an increased prevalence
of asthma symptoms among children in the area as a result of refinery
emissions and provide a substantive basis for community concern. The
methodology also provides a low cost means of testing hypotheses about point
source pollutant effects on surrounding populations of children.
PMID: 19781087 [PubMed - as supplied by publisher]
