The sewer is a treasure trove for researchers who want to find out more about people's behaviour and health, a Norwegian-Australian research group says. The photo shows VEAS, the sewage treatment plant for 600,000 people in the municipalities of Asker, Bærum and Oslo. Kjell Rune Jonassen from VEAS is talking to Malcolm Reid, research manager at the Norwegian Institute for Water Research (NIVA).

Researchers find evidence of anxiety and alcohol use in wastewater

Norwegian and Australian scientists can now learn more about people's health from what they find in our untreated wastewater.

In sewers that drain areas where people have less education and lower incomes overall, researchers find higher levels of both prescription painkillers and antidepressants.

"In areas where people have more money and higher educational levels, we found higher levels of vitamins," researcher Saer Samanipour from the Norwegian Institute for Water Research (NIVA) says in a press release.

In more affluent residential areas, wastewater reveals that residents eat a diet with a high fibre content and lots of citrus fruits. And consume more alcohol.

Based on the wastewater running through our sewers, the research team says it can say something about both the eating habits and the health of people living in a particular area.

Sewerage becomes socio-demographics

Previous sewage studies have been used to find remnants of illegal drugs. You can read more about that research in this article: Sewage detectives scour wastewater for drugs.

Now these same Norwegian and Australian scientists believe that they can learn much more about us from the substances they detect in our wastewater before it runs into a sewage treatment plant. Among other things, they believe they can say a lot about people's educational levels and finances from what gets flushed down the toilet.

In this way, samples from wastewater can be useful for studying the sociodemographic factors in different populations.

This study was funded by Australian authorities along with the regional research fund for Oslo and Akershus. The study was done in Australia in 2016, the same week as the country held a census. Norwegian researchers now see this as a useful tool in Norway as well.

Various anxiety drugs

Researchers from NIVA and the University of Queensland in Australia found that untreated wastewater showed a clear connection between lower educational levels and household incomes — and higher consumption of blood pressure medicines, painkillers and antidepressants.

In urban areas where more elderly people lived, researchers found higher levels of morphine and other drugs related to age-related chronic disorders.

The scientists pointed out, however, that the amount of anxiety-reducing drugs that can be detected in wastewater is equally high, regardless of whether people live in a residential area with higher or lower incomes. At the same time, they see that the types of anxiety-reducing medication people use clearly vary between different socioeconomic groups.

The Norwegian and Australian researchers believe our sewage shows that people from all walks of life are equally affected by anxiety. At the same time, they believe that people with lower educational levels and perhaps more physically demanding jobs also need pain relief to help with their anxiety symptoms.

Sweeteners and drugs

The use of antibiotics varies little between different social groups, the sewage told the researchers.

The sewage also showed little differences in the use of artificial sweeteners.

But the wastewater indicated a clear reduction in tobacco use in areas where people belonged to the middle class and upper middle class. And more people smoked in areas where many live alone.

Not surprisingly, the researchers found that if they found a lot of residual antidepressants in the sewage, they also found a lot of anxiety drugs, methadone, codeine and morphine.

Is it OK to look in your sewer?

One relevant question in the context of this study is whether we think it is ethical to have someone investigate our untreated wastewater.

Or do researchers who look at our leavings show disrespect for people's privacy?

The researchers themselves point out that this research method allows them to learn a lot, while also ensuring the anonymity of individuals.


P.M. Choi et al.: «Social, demographic, and economic correlates of food and chemical consumption measured by wastewater-based epidemiology», PNAS, 2019.


Read the Norwegian version of this article at

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