Scientists are warning that drinking water supplies in parts of rural West Africa are being contaminated by lead-containing materials used in small community water systems such as boreholes with handpumps and public taps. They analysed scrapings taken from the plumbing of 61 community water supply systems in Ghana, Mali and Niger. Eighty percent of the tested systems had at least one component that contained lead in excess of international guidance. Lead is released into the water when the components corrode.
The study, by a research team from the University of Leeds, University of North Carolina at Chapel Hill and Boston University, also took samples of the water from those 61 water distribution systems, and from a further 200 taps and boreholes with handpumps. Sixty percent of the samples contained lead – nine percent were at a level that exceeded World Health Organisation guidelines. The researchers found that lead contamination was significantly associated with the use of lead-containing components in the water systems. There is no-known safe level of exposure to lead. It accumulates in the body and crosses the blood-brain barrier and can cause irreversible damage to cognitive and neurological development, particularly in children and babies in the womb.
Jamie Bartram, Professor of Public Health and Environment at the University of Leeds, who supervised the latest research, said the evidence demonstrated the need for coordinated and urgent remedial action. Of the 130 plumbing components tested by the research team, 82 percent had a lead level that exceeded the IPC recommended maximum. Brass components were the most problematic. The researchers say the use of brass in a water system increased the expected lead concentrations in drinking-water samples by a factor of 3.8. Where drinking water was contaminated, the mean value of lead in the water was approximately 8 micrograms in a litre of water – where a microgram is one-millionth of a gram. The individual values, the 95 percent confidence limit, ranged from 0.5 micrograms/litre of water to 15 micrograms/litre of water. The World Health Organisation guideline value is 10 micrograms/litre of water.
Source: Eurek Alert!
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