Annual report highlights, 2005/6 - Environment & Health Research Unit

Certain groups of South African children have blood lead levels that are high enough to be causing reductions in their IQ scores, inhibiting their performance at school, and compromising their ability to achieve over their lifetimes.

This result of research conducted by the group has contributed to the implementation of three critical steps that will ensure that future young South Africans will be better protected against lead in the environment: the phasing out of the use of leaded petrol in South Africa as from 1 January 2006, a decision by the Department of Health to regulate the use of lead in paint and the launch of the first nationwide lead awareness campaign by the Minister of  Health, Dr Manto Tshabalala-Msimang, on 6 December 2005. The MRC’s lead poisoning prevention research  team intends to continue conducting surveys of the blood lead levels of South African children in order to make sure that blood lead levels decline following the implementation of these steps, and also to identify groups of children at risk from other sources of lead.

21 December, 2006een commenced to determine the effectiveness of increased awareness and improved personal and domestic hygiene in preventing the exposure of young children to environmental lead.

Indoor air pollution caused by the indoor burning of biomass fuels has been associated with increased risk of child acute lower respiratory infections (ALRI) in developing countries. Whereas the sustainability of technical interventions such as cleaner fuels and improved cooking technologies has been questioned in poor rural contexts, the group found that a behavioural change intervention reduced child indoor air pollution exposure by over 90%. The percentage of households that burned fuel indoors was also reduced from 67% at baseline to 32% at follow-up.

It is estimated that a complete shift from indoor to outdoor cooking is associated with a 33% reduction in ALRI incidence, while a partial shift (i.e. sometimes cooking indoors and sometimes outdoors) is associated with a 7% reduction in ALRI incidence. The study highlights the feasibility of low cost strategies to reduce child indoor air pollution exposure (and ALRI incidence) in poor rural contexts in the medium term.

Housing, especially associated with poverty, is one of the most powerful determinants of health, as those who live in poor quality housing are likely to have poor health. Results from the Health, Environment and Development (HEAD) study, which monitors changes in living conditions and aspects of the physical, social and psychological dimensions of health in urban areas in Gauteng over a period of at least five years, show that depression and food security are the two main causes for concern. Relatively high proportions of respondents in Riverlea (20%), Braamfischerville (22%) and the informal settlements (25%) reported they felt depressed most or all of the time. In these areas too, respondents reported a serious concern in relation to food security. In Riverlea, Braamfischerville and the informal settlement areas respectively, 23%, 32% and 36% of respondents said that children sometimes, often or always go to bed hungry because of a lack of food.

Making paint safe again
Although researchers have known since the early 1980s that South African children were exposed to high levels of lead, the source was mainly attributed to the lead added to petrol. This seemed to be confirmed when, after the introduction of unleaded petrol in 1996, MRC studies began to show associated reductions in child blood lead levels.

However, a study conducted by the Health and Development Research Group in 2002 showed that lead was still very much present in the blood of South African children – and paint started to emerge as an important suspect in the search for its source.

Inspired by these findings, the MRC team collected paint and dust samples from the homes of the twenty children with the highest blood lead levels identified in the 2002 survey. The results showed that over one third of the paint samples and 79% of the dust samples had lead levels above the international standards.

These findings were worrying indeed, and the group of scientists next decided to examine the levels of lead in residential paint in houses across Johannesburg. Of the 239 homes they tested, 20% were found to have unacceptably high lead levels in their paint. Considering that the South African Paint Manufacturers’ Association had entered a voluntary agreement to limit the use of lead in paint in the mid-1970s, it came as a surprise that homes built after this time had paint with high lead levels.

A 2005 screening study of lead in certain children’s painted toys found that some of them contained as much as 135 903 micrograms of lead per gram of paint. This was an astounding 1 500 times higher than the recommended safety level of 90 micrograms. Painted toys with a high lead content included children’s building blocks and puzzles – toys that are commonly used in homes, schools and pre-school institutions.

These alarming findings were conveyed to MRC President Prof Anthony MBewu who, in turn, presented a technical report to the Minister of Health. The Ministry immediately took steps towards legislative action to regulate the use of lead in paint, thereby replacing the current voluntary agreement.

On 6 December 2005 Dr Manto Tshabalala-Msimang, the South African Minister of Health, launched the first nationwide lead hazard awareness campaign in the country at the Little People Pre-School in Riverlea.

MRC staff were, and continue to be, integrally involved in the design of information materials to support the campaign.