Blood lead levels in First Grade South African children : A geographic & temporal analysis
Date
2008-11-04T10:18:58Z
Authors
Mathee, Angela
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Abstract
Lead is a toxic heavy metal that has been extensively used in modern society,
causing widespread environmental contamination, even in isolated parts of the
world. There is now overwhelming evidence associating lead exposure with wideranging
health effects, including reductions in intelligence scores, hyperactivity,
shortened concentration spans, poor school performance, violent/aggressive
behaviour, hearing loss, delayed onset of puberty, anaemia, and in severe cases,
coma and death. In recent years consensus has been reached in respect of the
absence of a threshold of safety for key health effects associated with lead
exposure, and the permanent and irreversible nature of many of the health and
social consequences of exposure to lead.
The public health problem of environmental lead exposure has been widely
investigated in developed countries such as the United States of America where,
since the 1970s, policies and interventions have been followed by significant
reductions in blood lead levels amongst children. In developing countries, and in
African countries in particular, there is a relative dearth of information on the
sources, mechanisms of exposure and blood lead distributions in children, and little
action has been taken to protect children against lead poisoning.
This study was undertaken to determine the current distribution of blood lead
concentrations, and associated risk factors, amongst selected groups of first grade
school children in the South African urban settings of Cape Town, Johannesburg 7
and Kimberley, a lead mining town (Aggeneys) and two rural towns in the Northern
Cape province. A further objective of the study was to compare blood lead
distributions determined in the current study with the findings of similar studies
undertaken prior to the introduction in 1996 of unleaded petrol in South Africa.
The results show that over the past decade, blood lead concentrations amongst
first grade school children have declined considerably, but that large proportions of
children, especially those living or attending school in impoverished areas,
continue to have intolerably high blood lead concentrations, within a range that
puts them at risk of detrimental health and social outcomes. The major sources of
exposure to lead in the samples studied were leaded petrol, lead-based paint used
to decorate homes and schools, lead solder used in “cottage industries” and other
home-based lead-related activities, as well as the transfer of lead particles from
lead-related work settings into homes. Recommendations for policy and relevant
interventions for the South African context are discussed.
Description
Keywords
lead poisoning, environmental contamination, lead exposure, wideranging health effects, First Grades, school children, South Africa, blood lead concentrations, leaded petrol, lead-based paint, lead solder