Reducing Childhood exposure to lead study
University of Ibadan, Ibadan, Oyo State, Nigeria
Healthy children are the world's greatest assets
Arc. Eugenious Adebamowo, Department of Civil Engineering, University of Ibadan, Oyo State, Nigeria
Dr. Oluwole Agbede, Department of Civil Engineering, University of Ibadan
Professor Mynepalli Sridhar, Department of Epidemiology, Medical Statistics and Environmental Health, University of Ibadan, Ibadan, Nigeria
Professor Clement Adebamowo, Division of Oncology, Department of Surgery, University of Ibadan, Ibadan, Nigeria
Lead is one of the most ubiquitous and poisonous heavy metal. It is widely distributed in the environment (air, soil, sediment, surface and ground water, food, dust, paint) and biological systems. It occurs both naturally and as a result of human activities. One of the commonest sources of human exposure to lead is through exhaust from use of leaded petrol. However this practice is being discontinued worldwide thereby shifting the focus to other sources of lead exposure such as the domestic environment through house paint, potable water, house dust and soil.
The toxic effects of lead may involve several organ systems within the body and may vary from subtle biochemical effects to clinical features of lead poisoning (plumbism). Significant exposure affects the nervous, hematological, renal and reproductive systems leading to anemia, nephrotoxicity, developmental delays, hypertension and behavioral disorders etc. While both adults and children can suffer from chronic low dose lead exposure, the effect is more marked in children. Children can be exposed to lead chronically in the domestic environment through the use of lead-based paint, lead-contaminated water, and dust. Lead-based paints are the most common sources of exposure of children to lead in the domestic environment.
Nigeria, like many developing countries, has been undergoing severe economic crisis. This has led to significant reduction in activity in all aspects of the economy including the construction industry. As a result many housing units are old and have not been renovated for many years. They are therefore likely to have old, flaking paint which is associated with increased risk of childhood lead poisoning. Common paints available in Nigeria are mostly the gloss and emulsion varieties for house paints and silken and auto base for vehicle paints. Other special types exist, with most manufactured in Nigeria. Most paints containers only indicate direction for effective use and they have no information on composition.
Pipe-borne water is another common source of chronic low dose lead exposure in the domestic environment. In some areas with soft water, leaded water pipes and solders, the level of lead in the water rises significantly. Ordinarily, the concentration of lead in nature (e.g. ground and surface water) is generally low, but unwholesome human practices have led to somewhat increased levels in water especially run off water. With leaded water-pipes and solders, the level of lead in water can rise considerably. In Nigeria, there is poor municipal water supply with significant proportion of the population reliant on ground water and run-offs for their source of potable water. The lead level in such sources of water is often unknown and the water is hardly treated before use. However, several studies have shown that their levels were above the permissible levels.
Children can also be exposed to lead through dust inhalation and ingestion. The amount of lead ingested depends on the lead level of the soil, the looseness and whether the area is landscaped. Within buildings, window wells are the strongest independent predictors of blood lead levels in children, regardless of the condition of the building. With this background, we, members of this research team decided to start a comprehensive translational research program on lead exposure. We started with evaluation of the knowledge, attitudes and practices towards lead exposure in South Western Nigeria. This will enable us develop the most appropriate health education materials and message about this environmental health problem. These studies are now being published: