Unleaded petrol shows health benefits
MRC News
A recent MRC study shows that the introduction of unleaded petrol has
contributed to dramatic improvements in children's blood lead levels.
"The introduction of unleaded petrol has undoubtedly been of benefit to
young South African children," says Ms Angela Mathee, a Senior Specialist
Scientist at the MRC's Environment and Health Research Group.
According to her, preliminary results from a survey of children's blood lead
levels currently being undertaken by the MRC indicate that, on average, the
blood lead levels of first grade children attending schools in various Cape Town
suburbs has decreased by 57% since 1991. This was when unleaded petrol was first
introduced.
"The study showed that the average blood lead level among children
attending Cape Town inner city schools now equals 7 µg/dl. This is down from 16
µg/dl in the 1980s and early 1990s, when only leaded petrol was available at
concentrations ranging from 0,4 to 0,836 g/litre," she says.
An MRC study conducted in Cape Town in 1991 showed that more than 90% of
inner city children had blood lead levels equaling or exceeding the
international action level of 10 µg/dl. The figure for 2002 equals 21%.
Warning note
Ms Mathee cautioned however that at certain inner-city schools high
proportions of children (up to 29%) continued to have unacceptably high blood
lead levels. Such high blood lead levels have been demonstrated to have effects
on brain development, behavioural disturbances such as hyperactivity and an
inability to concentrate - which all impact on school performance.
"There is a strong need for further action to reduce exposure to lead in
the environment, and the associated risks to the health of this group," Ms
Mathee says.
"We are hopeful that the phase-out of leaded petrol planned for 2006
will further reduce South African children's blood lead concentrations -
bringing these closer to the level of 2 to 3 µg/dl, which we are now seeing
among children in countries such as the USA where the use of leaded petrol was
ceased many years ago," she says.
Further roll-out
Dr Halina Röllin, a Senior Scientist in the study team, explains that the
Cape Town component is the first of four phases of the MRC study. Further phases
are being planned for Greater Johannesburg and two rural sites.
"Further analyses of the results will focus on identifying environmental
and behavioural risk factors among children with the highest blood lead
levels," she says. "We are also taking the opportunity with this study
to establish baseline levels of manganese in children's blood, in light of the
recent addition of MMT (a manganese-based additive) to petrol, which commenced
in certain parts of South Africa recently," Dr Röllin continues.
"This is indeed excellent news for public health," says Dr
Malegapuru Makgoba, President of the MRC. "We look forward to further
public health benefits, especially for children, from the commendable petrol
lead phase-out planned for 2006 by the Department of Minerals and Energy."
Dr Makgoba added that the MRC plans to monitor children's blood lead levels
beyond 2006, especially among high-risk groups such as those living in
conditions of poverty, to ensure compliance with international action levels.
For more information about blood lead levels, please contact Ms Mathee at
tel.: (011) 717-2403, cell 082 464 7038 or e-mail amathee@mrc.ac.za.
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