Arsenic-contaminated water in Bangladesh, India and Vietnam is one of the most pressing health problems, but bacteria will be used to fight it.
Escherichia coli bacteria have an intrinsic ability to detect arsenic and have achieved that, genetically modified, by guessing arsenic emitting fluorescence. To do this, they have introduced in the bacteria the genes of the proteins that produce the color, together with those that give them resistance to arsenic.
Thus they have achieved the most sensitive arsenic test so far and have already started testing in Vietnam. It can only be used in a laboratory, as it cannot be forgotten that they are genetically modified bacteria.