Drug Substances Prevailing in the Air of New Zealand City

Four drug substances (caffeine, nicotine, methamphetamine, and THC) were quantified in ambient Auckland air during the weekdays and weekends over 5 weeks. These traces were analyzed by scientists at the University of Auckland and the findings were published in the journal Atmospheric Pollution Research. International drug use has increased by 30% between 2009 and 2019, a trend that is reflected in Aotearoa New Zealand (United Nations Office on Drugs and Crime, 2019). Aside from self-reporting, wastewater analysis is the only method currently used to estimate drug use in Aotearoa New Zealand.

Air Monitoring for Illegal Drugs: An Alternative for Wastewater Analysis

One of the key limitations of wastewater analysis is that it is restricted to areas of drug excretion. Wastewater drug analysis can also be affected by heavy rainfalls and drug stability in the wastewater sewer system.

Air sampling is an alternate method for estimating community-level drug use, which could potentially be used to identify areas of use, manufacturing, or handling. Drugs that are commonly smoked by users, such as methamphetamine and cannabis, can result in airborne emission that can create primary aerosol or gases that condense onto existing ambient particles.

As drugs are often found at small concentrations in urban air, large sample volumes and highly sensitive techniques, such as LC-MS, are typically employed in airborne drug investigations.

To better understand the concentrations of drugs in Aotearoa New Zealand's largest city, this method was developed for the off-line analysis of caffeine, nicotine, methamphetamine, and tetrahydrocannabinol (THC) within total suspended particulate matter.

Drugs of Abuse in Airborne Particulates in Urban Environments

The largest concentration of meth detected was 104 picograms (a picogram is one-trillionth of a gram) per cubic meter of air. The average for 10 samples over five weeks was 24.8 picograms per cubic meter.

Assuming an active dose of 5 milligrams and 16 cubic meters of air inhaled per person each day, it would take an individual over 8,000 years to inhale an active dose.

Methamphetamine concentrations were higher than in overseas cities such as Barcelona. Airborne drug concentrations spiked in the week leading up to the Christmas holidays and also over New Year’s Eve.

Unsurprisingly, nicotine had the highest average concentration of the four drugs at 4.91 nanograms (a nanogram is one billionth of a gram) per cubic meter, 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. However, they highlight that we don’t know as much as we should about what’s in the air that we breathe.



Source-Eurekalert