Home Sci-TechEnvironment West Africa: Lead Found in Rural Drinking Water Supplies in West Africa

West Africa: Lead Found in Rural Drinking Water Supplies in West Africa

West Africa: Lead Found in Rural Drinking Water Supplies in West Africa

Scientists are warning that drinking water supplies in parts of rural West Africa are being contaminated b y lead- containing  mater ials 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 le ad  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 a nd  boreholes with hand pumps .

Sixty percent of the samples contained lead – nine percent were at a level that   exceeded  World   Health   Organisation guidelines .

T he researchers found  that  lead contamination  was significantly associated with  the use of lead-containing components in water systems.

No-known safe  level

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.

Lead contamination in plumbing systems has been a  recognised  problem for decades which has been controlled in urban areas  served by large, piped water systems  by  implementing corrosion control and  using lead-free or low-lead components, enforced through testing and monitoring, building codes, and regulations.

Evidence shows there is still a problem in higher-income countries with lead contamination in water from private wells and small, piped systems. The picture in low and middle-income countries has been less well studied, although the problem is believed to be widespread – and the potential implications for public health are much greater because  of the  global scale and the  number of people who rely on  small  community water-supply systems.

In Sub-Sharan Africa alone, it is estimated that 184 million people use  boreholes with  handpumps to access water  and 112 million people use rural piped supplies .

‘Opportunity for effective prevention’

Jamie Bartram, Professor of Public Health and Environment at the University of Leeds, who supervised the  latest  research, s aid the evidence  demonstrated  the need  for coordinated  and urgent  remedial action.

“We have  an opportunity for effective prevention and improved water supply practice worldwide. The required actions are overdue and unquestionably beneficial. The cost of ensuring that components are lead-safe is negligible,” he said.

“Using certified-safe components has multiple benefits, minimizing  the risk to  other hazardous contaminants. In contrast, delay carries further disease burden, increases the ultimate cost of protecting populations, and accumulates remediation burdens for future generations. ”

The study,  Occurrence of Lead and other Toxic Metals Derived from Drinking-Water Systems in three West African Countries , is published in the journal  Environmental Health Perspectives .

The International Plumbing Code  (IPC) , from the  International Code Council , recommends that lead in a plumbing component should not exceed 0.25 percent, based on weight.

Of the 130 plumbing components tested by the research team, 82 percent had a lead level that exceeded the I PC  recommended maximum. Brass components were the most problematic. In fact, 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 .

Dr Michael Fisher, Assistant Professor at the University of North Carolina at Chapel Hill, led the study. He said: “It is clear is that lead is present in most tested systems in this study and finds its way into drinking water at levels of concern.

“These findings suggest several affordable, feasible, no-regrets opportunities to reduce or prevent this contamination from occurring. Collaboration among multiple stakeholders will be required to achieve rapid success.

“Le ad exposure from other sources like pa i nt and petrol ha s been successfully phased out  and lead ca n be successfully eliminated from drinking water systems through concerted and collaborative responses.“

Need for coordinated  action

The scientists say manufacturers could discourage the use of unsuitable components, for example through explicit labelling and engagement in professional networks.