Efforts to remove toxic arsenic from drinking water in the Indian state of West Bengal are failing, according to a study published this month.
Dipankar Chakraborti of Jadavpur University, who led the study, says that instead of trying to decontaminate groundwater containing high levels of arsenic, efforts should focus on supplying clean surface water to affected areas.
Chakraborti's team monitored 18 of 2,000 decontamination plants made by 11 different manufacturers in India, Germany and the United States, and installed at wells in West Bengal.
They found that none reduced arsenic to levels the World Health Organization considers safe.
Eightyper cent of local villagers had abnormal levels of arsenic in their urine.
The study is published in Environmental Science and Technology.
Excessive arsenic in well-water threatens the health of millions of people in West Bengal and neighbouring Bangladesh. The toxin can cause skin diseases and cancer.
Environmental Science and Technology 39, 4300 (2005)