This bizarre story popped up, uncritically reported on Reuters yesterday:
There's something in the air tonight: Cocaine
ROME (Reuters) - Scientists have discovered particles of cocaine and marijuana, as well as caffeine and tobacco, in the air of Italy's capital, they said on Thursday.
The concentration of drugs was heaviest in the air around Rome's Sapienza university, though the National Research Council's Dr. Angelo Cecinato warned against drawing conclusions about students' recreational habits.
Calling their study "the first in the world to show the presence of particles of cocaine suspended in the atmosphere of the city", the researchers said they took samples in Rome, the southern city of Taranto and in Algiers in North Africa.
Nicotine and caffeine were detected in all three, "showing how widespread consumption of these substances is and how they remain in the atmosphere", state-funded CNR said in a statement.The concentration of cocaine in Rome's atmosphere was only 0.1 nanogrammes (1 nanogramme is one billionth of a gramme) per cubic metre at its height during winter months, the researchers said. But the conclusions were worrying for public health.
"It is well documented that even small concentrations in the air of these pollutants can seriously damage health," said Dr. Ivo Allegrini of the CNR's Institute for Atmospheric Pollution.
approx .01 gram of cocaine visible in this photo
I have neither the time nor will to point out the multiple tiers of silliness in the above news item, except to reassure potential visitors to the great city of Rome, even if they should have the misfortune of straying within the vicinity of students, that one ten-billionth of a gram per cubic meter of cocaine, marijuana, tobacco, or caffeine (or even, heaven forfend, as a cocktail) shouldn't fill them with panic.
Assuming that one active dose of cocaine is about 100mg (consumed in one go), then at 0.1ng per cubic metre that means one dose in 10^12 cubic metres, i.e. a cube of air 10km each side. So, that's roughly the amount of air you'd breathe in 2 billion, billion, billion, billion, billion (2x10^15) breaths*. Or, put another way, normal breathing for somewhere in the region of two hundred million years (+ or - a few million years, depending on age/body weight/lung capacity etc).
Just think, if you had a list of other contents of that cubic meter, measured in ten-billionths of a gram , well you'd..
...nope. I just can't be bothered.
* thanks to Andrew Taylor