Earlier this month, the New England Journal of Medicine reported on an outbreak of lead poisoning among young people in Leipzig Germany.
None of the patients had any of the usual environmental risks for lead poisoning so the surge was a mystery.
However, after much investigation, a common link was found: they all were pot smokers.
When some patients provided the investigators with samples of their stash, one showed visual evidence of lead particles (see photo below).
The dealers were adding lead to their dime bags to increase the selling weights. Some 100 people ended up needing treatment for lead poisoning.