Sewage reveals secrets

In order to monitor the spread of the coronavirus, RIVM has been monitoring the sewage water since February this year. For example, the research institute first saw the national increase in the number of corona infections and later also the decrease in sewage water. RIVM now checks sewage water from 29 different locations across the country on a weekly basis. That number will increase to more than 300 audited locations in the near future.

Corona in stool

The wastewater research is an additional method to monitor the spread of corona. It is one of the ways to quickly extinguish a potential source of fire: someone can be infected with the virus, but have no complaints. However, the virus is then contagious to others and it can be found in the faeces – and therefore also in the sewage water. In that sense sewage water is a good predictor of an outbreak. The time between seeing a contamination in the sewage water and an actual increase in the number of corona cases has not yet been sufficiently investigated. The researchers currently assume a period of approximately one week.

Timely intervention easier

The amount of virus particles that a corona patient (whether or not sick) has in the stool differs per person. It is therefore impossible to say that an x ​​number of virus particles in the wastewater means that a y number of people are infected. One person can excrete a lot of virus particles, but it is equally possible that ten infected persons excrete very few virus particles. Nevertheless, sewage research is very important, say the researchers. It gives a good indication of a possible revival of the virus in a certain area. And that makes timely intervention a lot easier.

Sewage research: not for the first time

In the study, RIVM is collaborating with a large number of water boards and water boards, a water company and the Union of Water Boards. Every sewage treatment plant takes several samples every day to check the water quality. Part of this now goes to RIVM, where researchers check the samples specifically for the coronavirus. RIVM also previously conducted sewage research into polio and into bacteria that are resistant to antibiotics.

Research into drug use

Partly as a result of the aging population, the amount of medicine residues in the sewage and in the groundwater up. This has negative consequences for plants and animals. For example, the remains of the contraceptive pill can cause a sex change in fish. And painkillers change the tissue of fish. Not good developments, therefore, and that is why various parties (such as water boards and drinking water companies, but also healthcare institutions and RIVM) are making agreements to reduce the amount of medicine residues in the sewage and groundwater. For example, more and more hospitals first purify their waste water themselves before it is discharged and doctors try to limit the use of medicines by their patients. In addition, the techniques for purifying water are getting better and better. Do you have any medicines left? Then hand it in at the pharmacy or at the recycling center. In this way you ensure that the remains thereof do not end up in the sewage and groundwater.

Research on drug use

Sewage also tells a lot about the use of drugs. Every year, measurements are taken in our country as well as in many other European countries. For example, the 2019 measurement showed that there was a striking amount of cocaine and MDMA (ecstasy) in the sewage water in Amsterdam. And in Eindhoven, the sewage contained drug waste – a waste discharge of methamphetamine. It was also striking that in 2019 methamphetamine was present in the sewage water in Utrecht for the first time. The Trimbos Institute uses these measurements in the sewage water as additional information in research into drug use in the Netherlands.