The drinking water of Bangladesh, known to be contaminated with toxic agents, can be addressed, according to an international team of volunteer researchers, led by a scientist at The Hospital for Sick Children. Following years of study of the contaminants in the water, the team has developed a practical strategy to ensure its safety.
Over the three-year study, eleven scientists from four countries led by Dr. Bibudhendra (Amu) Sarkar, Senior Scientist Emeritus in the Molecular Structure & Function program at SickKids, and professor in biochemistry at the University of Toronto, collected groundwater samples from 67 tubewells in western Bangladesh – the worst affected area where this work was carried out – which were then sent to Dubai, France and the U.S. to undergo testing for every toxic element found above World Health Organization (WHO) guidelines. Bangladesh’s 150 million people rely on these wells, as the previous practice of drinking surface water was deemed unsafe due to high incidences of water-borne diseases such as cholera and typhoid.
Of the tubewells tested, 96 per cent exceeded WHO guidelines for at least one of the following: arsenic, manganese, uranium, lead, nickel, chromium, boron and barium. While arsenic remains the single greatest risk to public health, the current practice of testing every tubewell for arsenic alone is ineffective, since it misses many other toxins. Of the 67 per cent of tubewells with safe levels of arsenic, 87 per cent had unsafe levels of manganese and 64 per cent had unsafe levels of uranium.
“While not all of the tubewells showed dangerous concentrations of arsenic, over 60 million people are drinking unsafe water,” explains Dr. Sarkar, the research team leader. “Public education has raised awareness of the link between arsenic poisoning and many types of cancer, but the dangers of chronic ingestion of manganese, which is associated with neurological damage, including parkinsonian disorders, and chronic uranium ingestion, linked to kidney and bone damage, remain unclear. As life expectancy continues to rise in Bangladesh, the prevalence of chronic disorders is likely to grow.”
Home-scale drinking water treatment systems are on the market, but most have only been designed to remove arsenic. They also pose a problem if the arsenic laden sludge created as a by-product is disposed of unsafely and re-enters the ecosystem. Until a long-term sustainable solution can be found, the research team proposes a three-step testing strategy which includes systematic, graduated testing of the tubewells. This proposed testing program is economical because it prioritizes the analysis of toxic elements, in order of highest levels of concentration found, and stops the testing once a sample is found to be unsafe for use as drinking water. An earlier societal study by this team showed that 90 per cent of western Bangladeshis are willing to share safe tubewell water with their less fortunate neighbors.
The team hopes its findings will prompt similar studies in the densely populated state of West Bengal in India, which borders western Bangladesh, and where aquifers with similar characteristics are found and issues of toxicity may be similar. Other plans include continued monitoring of Bangladesh’s drinking water and a study of its health effects on the paediatric population.
This was the third related study conducted by this team of “scientists without borders.” The current study was supported by Better Life Laboratories, Norwich University, the Bangladesh Association for Needy Peoples Improvement, CNRS at the Université de Bordeaux 1, and SickKids Foundation.