Medicines are supposed to work in the body. However, depending on the preparation, up to 90 percent of the active ingredient is excreted unchanged and ends up in the waste water. According to the Federal Environment Agency (UBA), sewage treatment plants only intercept some of the substances. Drugs can therefore be detected in water as well as - in significantly smaller quantities - in drinking water.
It is true that manufacturers have to carry out studies on environmental behavior and toxicity. According to experts, however, the results are hardly ever made public. "Environmental authorities and the public often don't have access to the data," explains lawyer and environmental scientist Kim Teppe. As a result, effective water protection is made considerably more difficult. In contrast to industrial chemicals, for example, drug manufacturers have only had to submit data to the approval authorities and can also rely on extensive exceptions, so that in practice no data is often submitted at all, as Teppe explains.
EU plans new human medicines legislation
Meanwhile the wind is changing. Negotiations for new regulations are underway at EU level. The Commission has announced that it will present a first draft of the new human pharmaceutical law in the coming days or weeks. "Hopefully, environmental concerns such as closing data gaps and data transparency will then be addressed at least to some extent," hopes Teppe, who has been working for the Federal Environment Agency (UBA) for several months. In 2022, she was awarded the Körber Foundation’s German Study Prize for her legal doctoral thesis on the problem at the Hamburg University of Applied Sciences (HAW) and the University of Hamburg.
The substance diclofenac - in Germany, among other things, a component of ointments that are supposed to work against pain - is an example of how medicinal substances can have surprising and terrible consequences for nature and the environment: When Indian farmers began in the 1990s to feed their cattle with Treating diclofenac began a mass die-off of vultures. Stocks shrank by 90 percent or more, some species almost died out. Even the smallest amounts of the drug cause excruciating, fatal kidney failure in birds of prey that ingest it while eating carcasses.
80 tons of diclofenac per year in Germany alone
In Germany alone, around 80 tons of the active ingredient are used every year. "A maximum of six percent arrive at the desired destination in the body," says Gerd Maack from the UBA's specialist group for the environmental assessment of medicinal products. "The skin is an effective barrier, that's its job." When applied as an ointment, the majority of the active ingredient contained goes into the sewage when washing hands, showering or washing worn clothing. Only part is eliminated in the sewage treatment plants.
The EU Water Framework Directive now provides for a further purification stage, and more and more 4th purification stages are being installed in Germany too. They hold back trace substances, for example through so-called ozonation or activated carbon filtration. "But many active ingredients such as X-ray contrast media just rush through there," says Maack from Uba. Various other measures are therefore being discussed, such as an environmental compatibility traffic light as additional information for specialist staff. "Active ingredients such as diclofenac should no longer be sold without a prescription," says Maack, another possibility.
Health mentality needs to change
Maack is convinced that the diclofenac ointments are often not medically necessary - with the exception of arthritis. "People need to be much more aware of what they put into the environment when they use it." Experts have been emphasizing for years that the mentality when it comes to health issues in Germany must change fundamentally: more willingness to take action, such as a better diet and a higher level of exercise, is necessary. "Part of the problem is that there's a common belief that a drug or treatment should fix every disease and you don't have to do anything yourself," says Maack.
In Germany, thousands of tons of biologically active substances from human and veterinary medicine are currently released into the environment via waste water, sewage sludge and liquid manure. More than 2000 different substances are on the market. The problem will become more explosive: the baby boomer generation is reaching retirement age - and older people in particular are taking a lot of medication. Compared to 2015, an up to 70 percent increase in the use of prescription drugs can be expected by 2045, says UBA expert Maack.
Substances add up in the environment
In addition, the amounts of many substances in the environment add up. "Drugs are often very stable compared to other chemicals," explains Maack. After all, they are created to survive inhospitable parts of the body such as the gastrointestinal tract and passages through cell walls. In the environment, they are often only broken down very poorly and retain their biological effectiveness for a long time.
When it comes to new developments, pharmaceutical companies pay attention to an even longer shelf life - for example, so that medicines only have to be taken once a day instead of twice a day, says Maack. So far, no attention has been paid to environmental compatibility during development. The pharmaceutical company association vfa states that it is only possible to a limited extent to develop chemical-synthetic active ingredients that are readily biodegradable from the outset.
Substances also get into drinking water
More and more, more and more durable: What does that ultimately do? It is difficult to unequivocally prove concrete consequences. Reliable connections have not yet been recorded for humans. Phenomena observed in the environment can only rarely be traced back to individual pollutants because there are countless pollutants and influencing factors that typically interact in a complex network, as Maack explains. In addition, there are chronic effects and changes in the genetic material, which are even more difficult to track down.
What is clear is that the substances inevitably get into drinking water and mineral water through the withdrawal of water from bodies of water and groundwater. "It's not necessarily less polluted than water from the tap," says Maack. The concentrations are usually far away from the therapeutically effective ones. However, the possible long-term consequences for humans and potential interactions are completely unclear, Maack points out. "We are all the long-term subjects for this."
