Adelaide has recorded the highest methamphetamine use of all the cities in the world compared in a paper based on wastewater samples.

Key points: Drug use was measured in 120 cities around the world through its presence in wastewater

Drug use was measured in 120 cities around the world through its presence in wastewater Adelaide had the highest methamphetamine use among the cities tested

Adelaide had the highest methamphetamine use among the cities tested An Australian academic involved in the study says the drug's prevalence has declined since 2017

The paper published in the journal Addiction on Wednesday was the largest wastewater-based study undertaken in the world.

Adelaide, Canberra and Toowoomba were the three Australian cities out of 120 worldwide to have their sewage monitored in the study of 60 million people between 2011 and 2017.

In 2017, Adelaide's wastewater revealed between 507 and 659 milligrams of methamphetamine — or "ice" — per 1,000 people each day, compared with between 270 and 331mg in Canberra and Toowoomba.

The only foreign city to come close was Seattle, with 418mg on average over the three years the city's wastewater was tested.

It was the only US city to be part of the study, which mainly focused on Europe.

Canberra had a much higher cocaine use than the other two Australian cities.

Researchers mapped the use of amphetamine, methamphetamine (also known as ice), ecstasy and cocaine.

The highest cocaine levels were in the British cities of London and Bristol, Amsterdam in the Netherlands, Antwerp in Belgium, and Zurich, Geneva and St Gallen in Switzerland.

Amphetamine use was highest in Belgium and the Netherlands, which was also the highest for ecstasy, also known as MDMA.

One of the lead authors of the study said use of ice had been decreasing in South Australia. ( Supplied: SA Police )

Ice use high but going down: researcher

University of South Australia research associate Richard Bade was one of the lead authors of the study, which involved 41 international institutions, including the University of Queensland.

Dr Bade said methamphetamine use was linked to several health conditions, including mental disorders, elevated heart rates and domestic violence.

"It's important we determine the scale of the illicit drug market so that countries can work out the best way to tackle a $100 billion industry, which is contributing to the global burden of disease and affecting the economic development of many countries," he said.

He said the study did not necessarily find that Adelaide was the world leader in methamphetamine use because many countries and cities were not involved in the study.



"To put into a bit of context, the study was from 2017 and in fact since that time methamphetamine use in South Australia has actually been on the decrease," Dr Bade said.

"… And there's been plenty of initiatives around that reduction of methamphetamine use in Adelaide [since 2017]."

The study's authors found the wastewater results generally matched with other methods of estimating drug use, such as surveys and seizures by authorities.

It found wastewater testing "provides updated and objective estimates of drug use and allows identifying and highlighting new trends and specific profiles of use much earlier" than other indicators.