Methamphetamine, nicotine, caffeine and tetrahydrocannabinol (THC) have been detected in downtown Auckland's air pollution, according to a new study.
Traces of the drugs were caught by filters at a pollution monitoring site on Customs St near the bottom of Queen St, according to an analysis done by scientists from Waipapa Taumata Rau - University of Auckland.
Levels of the drug were higher than in overseas cities, such as Barcelona in Spain, and spiked in the week leading up to Christmas and also over New Year's Eve.
Master of Science student Olivia Johnson and Dr Joel Rindelaub, a research fellow in the School of Chemical Sciences, revealed the largest concentration of meth detected was 104 picograms (a picogram is one-trillionth of a gram) per cubic metre of air, which would mean it would take an individual over 8000 years to inhale an active dose.
The average for 10 samples over five weeks was 24.8 picograms per cubic metre.
Nicotine had the highest average concentration of the four drugs at 4.91 nanograms (a nanogram is one billionth of a gram) per cubic metre, a level lower than in many cities overseas.
Caffeine, likely from sources including steaming takeaway coffees, and THC, from people smoking cannabis, were both detected at lower average concentrations than in studies elsewhere.
"The results aren't as concerning as a headline might make them sound," Dr Rindelaub said.
"However, they highlight that we really don't know as much as we should about what's in the air that we breathe."
The study, the first of its type in New Zealand and Australia, says the airborne monitoring of drugs could be complementary to wastewater analyses, which are carried out for the likes of cocaine, fentanyl, heroin, methamphetamine and MDMA to track drug consumption in communities around the country.
Dr Rindelaub and Johnson said it would be easier to assess the effectiveness of policies such as restrictions on tobacco products with the technique.
Hamish Patel, a PhD candidate and air quality scientist at Mote Ltd., and Associate Professor Gordon Miskelly also worked on the study, which used liquid chromatography with tandem mass spectrometry to analyse samples collected from December 7, 2020, to January 11, 2021.
The study was only looking for methamphetamine, nicotine, caffeine, and THC, so it's unknown what other drugs may be floating around.
In a separate study published in December last year, Dr Rindelaub and colleagues said microplastics swirling in Auckland's air are equivalent to more than three million plastic bottles falling from the sky every year.
Over 3300 premature deaths per year are related to air pollution in Aotearoa, Dr Rindelaub said.
