Zimbabwe: Dying rivers dry up livelihoods

In an effort to concentrate their yield, the `makorokoza’ often mix the residual ore with mercury, a practice that Steady Kangata, the education and publicity manager for the Environmental Management Authority (EMA), said created a health hazard for people and animals downstream. 

“Mercury has the tendency to accumulate in the bodies of animals and humans who consume it, and in the case of people, if it gathers to a certain level, it can cause hair loss and the breakdown of the nervous system,” he said. 
http://www.thezimbabwemail.com/zimbabwe/11566-dying-rivers-dry-up-livelihoods.html