This week's crime allowed Stockholm to test wastewater in the central and southern parts for seven days to map how many drugs are in circulation. The state research institute RISE analyzed the levels of drug residues in the wastewater, which were washed every day by the 850,000 people living in the area.

"The analysis responses showed the highest levels we have seen since we started measuring in Sweden," says Johan Lindberg, chemist and group manager at RISE, who analyzed the test results from the collected wastewater.

Over 200 kilograms of cannabis in one week - the biggest income of all

Converted to weight, 223.5 kilos of cannabis, worth a total of around SEK 24.6 million, was smoked this week. This shows that cannabis is the biggest source of income for the lakes.

Cannabis is by far the largest source of income for the lakes. Photo: SVT Grafik

The cocaine corresponds to almost 3.4 kilos and a value of SEK 3 million. An additional three million was spent on 13.5 kilos of amphetamine. During the week before payroll in October, a total of almost SEK 31 million was burned on drugs in Stockholm.

Do half of Stockholmers smoke cannabis?

The test was done over seven days to get the most reliable figure possible on drug habits. On average, the study found that every day, the equivalent of 255,600 doses of cannabis, 4,810 lines of cocaine and 64,443 doses of amphetamine were consumed.

During the week, it was Tuesday that most drugs were consumed in the area. On Tuesday, 440 doses of cannabis were consumed per thousand inhabitants. 4.7 doses of cocaine and 79 doses of amphetamine.

The use of different drugs varies over the week - where cocaine consumption almost doubles over the weekend. Photo: SVT Grafik

But that does not mean that almost half of Stockholmers used cannabis. The test says nothing about how many people have used the drug, but only gives answers to how large quantities have been washed down by the examined Stockholmers.

More cocaine on the weekends

The analysis also shows that drug behavior changes over the week - cannabis use is greater during the weekdays and decreases during the weekends when cocaine sales instead go up to double.

- It is one of the most reliable tests one can do to find out what the drug habits look like and should be carried out over time in Sweden's largest cities to map how much drugs are in circulation, says Johan Lindberg at RISE.

The water was tested in parts of central and southern Stockholm where 850,000 people live - but where more are staying. Photo: SVT Grafik

The basis plays a role: "The figures should be interpreted with caution"

The fact that the test was done at Henriksdal treatment plant, which receives wastewater from central Stockholm, among other things, can affect the figures - it is likely that more drugs are used around the pubs in the inner city than in the rest of Stockholm. In addition, drugs in central Stockholm are used by people who live in other parts of the city, or who are on a temporary visit.

- The figures should be interpreted with caution, one must take into account that the population base may vary and that there may be people traveling to Stockholm, it is those who were in Stockholm during these days that we have tested drugs, says Johan Lindberg at RISE .

This also means that the total figure of just over SEK 30 million would be significantly higher if the whole of Stockholm were investigated.

See more in Week's crime tonight at 21.