A Fix for Fixtures: Addressing Lead Contamination in West African Drinking Water.

Lead in drinking water is an issue of global concern.1 New research published in Environmental Health Perspectives documents the problem in previously unexamined areas of rural West Africa,1 further indicating the wide reach of this harmful contaminant.

Lead rarely occurs naturally in drinking water; most often it leaches from lead-bearing plumbing components, such as pipes, solder, or brass fittings. Characteristics of the piped water, such as low pH level or low phosphate content, can cause these components to corrode over time, allowing the metal to contaminate drinking water.2

The new study of drinking water in three West African countries pinpoints plumbing fixtures, such as brass taps, as a source of high lead levels. Image: © Riccardo Mayer/Shutterstock.

Health scientists have not identified a safe level of lead exposure.3 In children, even low-level exposures may cause nervous system damage, learning disabilities, shorter stature, hearing loss, and impaired formation and function of blood cells.4 Worldwide, an estimated 800,000 children have blood lead levels at or above ,5 the concentration at which the U.S. Centers for Disease Control and Prevention recommend intervention.6

In the new study, a team of researchers based at the University of North Carolina (UNC) Water Institute sampled 261 community water systems (hand pumps and public taps) in rural areas of Ghana, Mali, and Niger.

In 9% of drinking water samples, lead concentrations exceeded the World Health Organization (WHO) guideline value of .4 Additional testing of metal scrapings obtained from plumbing system components identified lead-containing brass fittings as an important source of contamination, with galvanized steel and other lead-containing materials as secondary sources. The authors concluded that their results are broadly comparable to those obtained from studies in many high-income countries.7,8,9 In 2019, the U.S. Geological Survey National Water Quality Program reported analyses of water from more than 8,300 wells across the United States. In about one-third of the wells—concentrated in eastern and southeastern states—they identified characteristics that could cause lead in plumbing components to leach into tap water.10 Similarly, a study of private drinking water systems in Virginia found that 20% of 2,146 tap water samples had lead concentrations exceeding .7

Even though the samples from Ghana, Mali, and Niger exceeded regulatory guidelines less frequently than those in the Virginia study, the same underlying issues are responsible: corrosion of lead-containing plumbing components, says Michael Fisher, an assistant professor of environmental sciences and engineering at UNC–Chapel Hill and first author of the new article. “If you look at occurrence and concentrations, I think a strong case can be made that these are qualitatively similar stories about a qualitatively similar process in Virginia and largely rural West Africa settings,” Fisher says. In both settings, testing also revealed an association in tap water between levels of lead and copper, often found together in brass fittings.11

Kelsey Pieper, an assistant professor at Northeastern University in Boston, Massachusetts, who served as lead author of the Virginia study, says the new paper is notable for drawing a connection between two seemingly disparate settings and calling attention to lead contamination in a previously understudied context. “I think this paper does a great job of starting a new dialog about lead in drinking water in sub-Saharan Africa. It is starting a discussion that really hasn’t been had before,” she says. Pieper was not involved in the new study.

University of South Florida associate professor Jeffrey Cunningham, also not involved in the new study, says the article broadens researchers’ and public health authorities’ understanding of not only where leaded plumbing components are contaminating drinking water sources but also how. Cunningham worked on a 2015 study in Madagascar that found 67% of drinking water samples drawn from household wells had lead concentrations exceeding WHO guidelines.12

“One of the big things that I took away from [the new study] is the importance of brass,” Cunningham says, noting that much of the contamination in the Malagasy communities he studied derived from all-lead components fashioned from melted-down car batteries. “As we proceed in our own research,” he says, “I think that’s one of the things that’s going to be important for us to look at.”

Fisher suggests that risk of lead exposure can be reduced by using lead-free components when replacing existing fixtures or installing new systems. Getting these components to rural areas that lack easy access, from the United States to Africa and beyond, may require addressing global supply chains. “If the wrong parts are getting into the supply chain and used for drinking water systems in our backyard,” Fisher says, “there may well be an issue globally.”