This is a new one on me. I knew that trace amounts of cocaine was found on money pretty much everywhere but it now seems that if you are in Rome all you have to do is inhale the air outside:
A study of psychotropic drug levels in ambient air from eight Italian cities found background levels of cocaine, cannabinoids – the active ingredients in marijuana – nicotine and caffeine in every urban centre.
Turin had the highest concentrations of cocaine, says Angelo Cecinato at the Institute of Atmospheric Pollution Research in Rome. Meanwhile, Bologna and Florence had some of the highest cannabinoid levels, which Cecinato attributes to the large student populations in the two cities.