A wee dram

摘要

We often hear about people surviving where water is scarce by drinking their own urine. But can drinking urine - one's own or anybody else's - harm you? If so, how? Does it have to be fresh? And how many times can a person recycle it? Obviously it can't last forever. ■ Somebody else's urine may not kill you, but it won't do you much good if it is carrying pathogens, pharmaceuticals or food allergens.