Air in eight Italian cities is riddled with drugs, according to a recent study conducted by the Institute of Atmospheric Pollution Research at the National Research Council in Rome. The study analyzed the air for the presence of two legal drugs: caffeine and nicotine, and two illegal drugs: cocaine and cannabinoids.Commissioned by Italy's anti-drugs department, contents of the air from six cities were analyzed every day for a year, while two cities had their air studied on seven random days per month. The researchers tested for each of the substances using samples taken from the cities' air quality monitoring stations.
A hazy combination of smoke and fog blurs the view of Bologna from the mountains above the northern Italian city, which scored high in the environmental survey. The smog is made up of what the scientists call particulate matter or fine particles suspended in the air.
While particulate matter - or PM - can be produced by natural sources like volcanoes and dust storms, the PM found in cities is usually caused by people, such as factories and cars.
What's with PM?
"When they started measuring PMs, they understood that these concentrations needed to be kept under control," Cristina Volta of the Bologna regional environmental protection agency (ARPA) told DW. "Studies like this are important to discover and start tackling an issue rather than ignoring it."
Scientists first discovered psychotropic substances - drugs like caffeine, nicotine, cocaine and cannabinoids - in water, and are now measuring it in the air. There is worry in towns like Bologna: located in the giant basin of the Po Valley, where there's lots of traffic, it's rarely windy, and the air tends to stagnate.
"Tests that showed the presence of these substances in the water had already made us prick up our ears," said Volta. "But finding them in ambient air together with fine particles is a step forward in our knowledge about the presence of these substances."
In Europe, there's only been one similar study which was conducted in three Spanish cities. They fared marginally better than the Italian ones. Another study from Latin America revealed much higher levels of psychotropic substances in the air. Volta said she would like to see more extensive PM research worldwide.
"Even if we know they are being consumed, we don't yet know how they disperse in the air and what effect they have," Volta said, adding that the influence of PM should not be underestimated.
Lab analysis of the filters revealed high levels in all the cities studied - with the northern Italian city Turin coming out worst for all both sets of legal and illegal substances, while Bologna had some of the highest levels of caffeine and cannabinoids.
The local population in the cities studied weren't shocked at the thought of caffeine and cocaine in the air."The community of the people that attend university is very big," said one local resident. "Therefore you can find a higher percentage of people that smoke marijuana."
"I'm from Florence and, for example, in the Arno River there is the highest rate of cocaine in the water," said another native. "Maybe it's more dangerous smog and things like that than cocaine or caffeine or cannabis."
But not everyone is unfazed, one man said the results of the study make him more concerned about the use of drugs.
"The fact that Bologna is one of the cities where they found the highest levels and the fact that it's a city full of students should maybe serve as an incentive to implement stricter controls (on drugs) in the city," he said.
Volta, however, said there's no reason for the people of Bologna to fear getting stoned during a walk in the park.
"We're talking about concentrations in the region of nanograms and sometimes even as little as picograms per cubic meter of air," Volta clarified. "These are very low concentrations that are important indicators of consumption."
The study was conducted to find an index to tell more about the consumption and everyday use of psychotropic drugs. Though current levels are no cause for immediate concern, Volta said the next phase of research should focus on long-term passive exposure to these substances.