A Remedy for Deadly Water
In Bangladesh last year, Johanna Mathieu saw unmistakable signs of the poisoning afflicting the impoverished country. “Everyone would show us their hands,” says the 26-year-old doctoral student in mechanical engineering. The painful and disfiguring sores, blisters and dark spots are telltale indicators of the deadly toll exacted by arsenic-laced water wells.
Mathieu heads a student team at UC Berkeley responding to what experts consider the largest mass poisoning in history: millions of Bangladeshis are drinking water containing hazardous levels of arsenic. “They say between 30 and 70 million people are exposed,” says Mathieu. She is working with an interdisciplinary group led by Ashok Gadgil, a senior scientist at Lawrence Berkeley National Laboratory and an adjunct professor in the Energy and Resources Group, to develop a simple, inexpensive process for removing the toxic element from the water supply.
Waste ash from coal-fired power plants may provide a solution. Gadgil has discovered a method of coating the powdery and readily available coal ash with oxides, hydroxides and oxihydrides of iron. The resulting material binds to arsenic and can then be filtered out of the water. This material, which resembles cocoa powder, is called ARUBA (for “arsenic removal using bottom ash”). “We’re trying to find something both technically effective and affordable for people in one of the poorest countries in the world,” says Gadgil, whose project is supported by UC Berkeley’s Blum Center for Developing Economies and the National Collegiate Inventors and Innovators Alliance (NCIIA). Mathieu, who is working to scale up production of ARUBA and design a filter system, says, “I can say with confidence that the method surely works.”
Arsenic occurs naturally in groundwater and has been found in 1.5 million of the 5 million tube wells tested in Bangladesh, according to UNICEF. Along with the lesions observed by Mathieu, cancer, neurological problems, hypertension and death are among the chilling health effects of arsenic poisoning. Outside the city of Jessore last spring and summer, Mathieu measured arsenic levels of more than 1,000 parts per billion—100 times the World Health Organization’s recommended exposure limit—in some village wells.
This summer, she is returning to Bangladesh with Gadgil and four other Berkeley students to test a prototype filter system and explore how it might be introduced. Their vision calls for village-wide treatment facilities, each capable of delivering clean drinking water to 2,000 people. The annual cost would be $6 to $14 for a household of five, with each member using two liters of water daily.
Many Bangladeshis in affected areas are agricultural laborers who earn just a couple of dollars a day. Partnering with researchers from two Bangladeshi universities, the ARUBA team will assess the willingness of inhabitants to pay for clean water. The researchers also hope to identify a company interested in installing and operating the filter systems. “We really want to push it out the door to a company that has its heart in the right place and will want to take it on,” says Mathieu, a 2004 MIT graduate who previously taught school in Tanzania with the Peace Corps.
Ironically, many of Bangladesh’s tainted wells were installed in the 1970s by relief organizations hoping to halt a deadly epidemic stemming from pathogens contaminating surface water. The arsenic wasn’t discovered until the wells were tested in the 1990s.
Today, most Bangladeshis are aware of the problem—and accustomed to the steady stream of researchers who come to study it, says Mathieu. On her previous trips, “Everyone was asking, ‘Can you test our well? Can you test our well? We really need a solution to this.’”
Scientists say there may be more than one approach to a disaster of such magnitude. Gadgil is also investigating an electrochemical process for removing arsenic and already invented a system for inexpensively disinfecting surface water with ultraviolet light.