Do not urinate in the lake if you are taking these medicines – 2024-08-11 00:13:18

A study conducted by the University of Stockholm reveals that urine can increase the amount of blue-green algae in water. The picture shows blue-green algae on Hietaniemi beach. Jani Korpela

Can I pee in the water while swimming? Does a few desi people’s urine really spoil a huge amount of water?

Merikarvia magazine says that an adult produces between one and two liters of urine per day. It contains the nutrients that blue-green bacteria, algae and other aquatic plants need for their growth, i.e. nitrogen and phosphorus.

In practice, urinating in water can increase the amount of blue-green algae. This is evident from a study conducted by the University of Stockholm in 2017, in which different deciliter amounts were added to containers containing seawater of human urine.

The study found that just three deciliters of urine in a thousand liters of seawater turned the water green.

There are also drug residues in human urine, which can become their own load on the environment. With the help of an expert, Iltalehti found out whether a swimmer splashing in natural waters should urinate into the water. The answer is clear.

Medicines are transferred from urine to nature

Human urine also contains drug residues in waterways, says an assistant professor at the University of Helsinki Tiina Sikanen from the Faculty of Pharmacy.

The human body removes foreign substances through urine. First, the medicinal substances are processed in the liver and they are excreted in the urine. Among other things, drug use is mapped with wastewater studies, where the concentrations of different substances are measured.

– If a person uses regular medication, there will always be drug residues in the urine, Sikanen says.

Finland has an excellent system of wastewater treatment plants, Sikanen says. Human urine and excrement are also cleaned from water at wastewater treatment plants, but because there are so many chemicals in the secretions, not all of them can be removed by the wastewater treatment plants, but some amounts always end up in the waterways.

Waste water treated in Finland ends up in the Baltic Sea before long.

– The amount of drug residues in water bodies correlates quite a lot with the population density, Sikanen elaborates.

Therefore, water bodies near cities naturally have higher concentrations than sparsely populated rural areas. In Finland, according to Sikanen, the concentrations are very moderate compared to countries in Eastern Europe or Central Europe, for example.

Many pharmaceuticals pose hidden threats

Medicinal substances are very different, as is their effect on water bodies and aquatic organisms. Effects are measured based on three different criteria, Sikanen says.

– Antibiotics, for example, are their own chapter. Antimicrobial resistance caused by them is of course a hidden threat all over the world. But in general, drugs are small molecules. They are designed in such a way that they bind to certain target proteins in humans and then they are actually eliminated with the urine, Sikanen says.

Environmental effects are studied using three different criteria. The first criterion is to assess whether the drug breaks down in the environment. Another criterion is to study the bioaccumulation of the drug, i.e. whether the drug is such that it accumulates in the body of fish, for example.

The third criterion is the concentration of the medicinal substance’s toxicity, which is compared to the concentrations measured in the environment. Toxicity can be studied, for example, with algae, water fleas, fish and earthworms.

– These are measured as part of the risk assessment required by the authorities, Sikanen says.

For example, the dose of diabetes medications or antibiotics is already high even for humans, and thus their environmental concentration is often high if it is compared to other medicinal substances.

Then there are also particularly harmful medicinal substances, which include, for example, anticancer drugs, Sikanen adds. Cancer drugs are already poison for humans, so they are also poison for the environment.

– Of course, if substances used as cancer drugs end up in that environment, they are harmful. However, their use is so small that the concentrations of cancer drugs in the water are not necessarily that terribly high. They do not necessarily exceed the limit concentration that causes adverse effects.

Quantitatively, there are the most anti-inflammatory drugs, such as ibuprofen and paracetamol, in water bodies. But they are not necessarily as harmful as, for example, anticancer drugs. According to Sikanen, the most important thing is how high the concentration of the medicinal substance is in the water.

So, if a citizen wants to take care of clean water, is it worth avoiding urinating in swimming water?

– Absolutely. If possible, go to the bathroom. I absolutely do not recommend urinating in water, even if there are no drug residues in the body. It is good to deliver all human waste properly, Sikanen says.

– That’s why there are toilets on the beaches too, which should be preferred.