A multi-year study of the level of "ice", or methamphetamines, in Adelaide's wastewater didn't just top the three Australian cities in the research, it was the highest concentration of the drug in the world.

In the largest study of meth in urban wastewater, the results published in the journal Addiction on Wednesday said Adelaide's wastewater revealed between 507 and 659 milligrams of methamphetamine - or "ice" - per 1,000 people each day.  Canberra's and Toowoomba's sewage had measured between 270 and 331mg.  

"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," said University of South Australia research associate Dr. Richard Bade, one of the lead authors of the study.  University of Queensland was also one of the 41 research institutions taking part in the study.  

The research spanned between 2011 and 2017, examining the sewage from 120 cities around the world with a total population sample of some 60 million people.  Out of all of those cities, only Seattle came close to Adelaide with 418 milligrams of methamphetamine per 1,000 people per day.  But the study was weighted towards Europe and Seattle was the only US city, so one could imagine how those numbers might skyrocket for cities across the American South with intense Meth problems, especially in Texas and Florida.