May 15, 2025
DHAKA – Thirty-two years ago, Bangladesh’s first groundwater arsenic was discovered in Chamagram village of Chapainawabganj by the Department of Public Health Engineering (DPHE). At the time, it was labelled as the largest mass poisoning in human history. Since then, hundreds of millions of dollars have been spent on testing tube wells, promoting alternative water sources, and raising awareness. And yet, millions of people in Bangladesh continue to drink water contaminated with arsenic every day. The question is: why?
The answer is not simple. The persistence of arsenic exposure is not due to a lack of scientific knowledge or technological solutions. It is the result of a complex set of barriers, such as hydrogeological, social, institutional, and economic factors, that continue to undermine mitigation efforts. Arsenic contamination is patchy and unpredictable. In a single village, some wells may be safe while others situated just metres away are highly toxic. This spatial heterogeneity in groundwater arsenic distribution in aquifers makes it difficult to apply one-size-fits-all solutions. Without regular and comprehensive testing, it is almost impossible for communities to know whether their water is safe.
Moreover, initial testing efforts in the early 2000s were large-scale but short-lived. Many wells that were once labelled safe have never been retested, and others have deteriorated over time. As a result, many families unknowingly drink from contaminated wells, either because the last test was conducted some 10 or 15 years ago, or because new wells were installed under the assumption that they were arsenic-free.
Institutional weaknesses also play a major role. There is no centralised groundwater authority in Bangladesh responsible for monitoring and managing drinking water quality. Different government agencies (e.g. Bangladesh Water Development Board, DPHE) often operate in silos, with little coordination between the departments of health and local governance. As arsenic mitigation projects come and go, communities are often left with infrastructure they cannot maintain or without the technical support needed to sustain safe water practices.
Social and behavioural factors are equally important. Many families prefer the convenience and control of their own household tube well, even if a safe community source is available further away. Women, who are typically responsible for collecting water, are reluctant to walk long distances or queue for water every day. Risk perception is low, especially because arsenic-related diseases take years to manifest. Without visible symptoms or immediate consequences, the urgency to switch to safer sources fades.
Meanwhile, the cost and maintenance of mitigation technologies remain prohibitive for many rural households. Filters often clog or break down, and community treatment plants fall into disuse without adequate maintenance or oversight. Rainwater harvesting systems, while effective in theory, often fail in practice due to poor design, insufficient storage capacity, or user disinterest. Piped water schemes have made progress in urban and peri-urban areas, but are still far from being universal in rural Bangladesh.
Yet, there are reasons for cautious optimism. DPHE has continued its nationwide efforts to reduce arsenic exposure, particularly in rural areas. One major project had focused on identifying high-risk communities, testing arsenic levels in existing wells, installing deep tube wells (such as No. 6), promoting rainwater harvesting systems, and building the capacity of local government institutions and communities to provide safe drinking water. These efforts reflect the government’s continued recognition of the seriousness of the crisis and its long-term impacts.
To truly end the arsenic crisis in Bangladesh, several additional actions must be taken beyond the lifespan of any single mitigation project. A new national-scale survey of tube wells is urgently needed to detect not only arsenic but also salinity, faecal contamination, and other chemical hazards that may compromise water safety. This must be followed by the establishment of a monthly or seasonal monitoring system at strategic locations across the country to track changes in groundwater arsenic and water quality over time.
Recent advances in artificial intelligence offer a powerful opportunity to support these efforts. Machine learning models can be used to develop high-resolution arsenic risk maps, enabling more targeted interventions. These data-driven tools can help prioritise areas for well-testing and safe water provision more efficiently than ever before.
Public awareness must also be significantly enhanced. This means not just campaigns, but formal inclusion of groundwater science and arsenic health risks in national primary and secondary education curricula. Educating the next generation is critical to breaking the cycle of exposure. This is currently missing in the primary school textbooks.
Finally, collaboration between the water and health sectors must deepen. Institutions with expertise in public health, such as icddr,b and others, should work in tandem with groundwater experts and engineers to monitor health outcomes, promote safe water behaviours, and respond to emerging risks. Only through such an integrated and sustained approach can Bangladesh achieve its goal of arsenic-free drinking water for all.
Professor Mohammad Shamsudduha teaches at Department of Risk and Disaster Reduction at University College London in UK. He can be reached at m.shamsudduha@ucl.ac.uk.
Views expressed in this article are the authors’ own.