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Drug residues as an environmental hazard

Medicines are supposed to work in the body.

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Drug residues as an environmental hazard

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. Sewage treatment plants intercept only part of the substances. Drugs can therefore be detected in bodies of water as well as – in much smaller amounts – in drinking water.

Manufacturers must conduct studies on environmental behavior and toxicity. According to experts, however, the results are hardly ever made public. "Environmental authorities and the public often cannot access the data," explains lawyer and environmental scientist Kim Teppe. As a result, effective water protection is made considerably more difficult.

For other substances such as industrial chemicals, biocides and pesticides, the results of ecotoxicological studies are publicly available. In the case of medicinal products, on the other hand, manufacturers have so far only had to submit data to the approval authorities and can also refer to extensive exceptions, so that in practice often no data is submitted at all, as Teppe explains.

In addition, the data may not be passed on to environmental authorities or the specialist public by the approval authorities. Even with a specific request from a water monitoring authority, manufacturers could classify parts or even the entire environmental dossier as requiring confidentiality with reference to business and trade secrets, says Teppe.

Why is there this difference between the substance groups? "The fact that medicinal substances also have consequences for the environment was not and is not as widely known as, for example, with pesticides, the public pressure was not there," Teppe cites one reason.

In addition, industrial chemicals are often used in much larger quantities, pesticides are used on the field and thus directly into the environment. However, it should also be taken into account that active pharmaceutical ingredients are specially designed for an effect in living beings and are often very persistent, i.e. are only slowly degraded.

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 at its meeting on March 29th. "Hopefully, environmental concerns such as closing data gaps and data transparency will then be addressed, at least to some extent," hopes Teppe. The lawyer herself submitted proposals to the EU Commission.

Kim Teppe was awarded the Körber Foundation's German Study Prize in 2022 for her legal doctoral thesis on the problem at the Hamburg University of Applied Sciences (HAW) and the University of Hamburg.

During her research as part of the "PharmCycle" project at the HAW, she experienced for herself how difficult it is to obtain data from ecotoxicological studies - and complained to the administrative court in Cologne for access to the environmental data. Since then, the procedure has been running, which, according to Teppe, could ultimately lead to a decision by the Court of Justice of the European Union (ECJ).

The ECJ could therefore decide that the environmental risk assessments of medicinal products are information about emissions within the meaning of environmental information law - they would then be made accessible on request, regardless of business and trade secrets.

"It would also be important that data for old active ingredients be supplied later," says Teppe, who has been working for the Federal Environment Agency (UBA) for several months. Such substances make up a large part of the available active ingredients, but were once hardly examined for their environmental effects.

On the list of so-called priority substances within the meaning of the EU Water Framework Directive, not a single active pharmaceutical ingredient has appeared, as Gerd Maack from the specialist group for the environmental assessment of pharmaceuticals of the Federal Environment Agency explains. Substances with a particularly high environmental risk are listed there because of their ecological or human toxicological effect and their widespread distribution in water bodies. For priority substances, legally binding standards are set, for example for controls and targeted measures for water protection.

Here, too, the situation is changing: Active ingredients such as the hormonally active substances estradiol and ethinylestradiol and the painkiller diclofenac could soon be on the list, and discussions are ongoing at EU level, said Maack.

For ethinyl estradiol, the concentration at which no effects on the ecosystem occur (predicted no effect concentration, PNEC) is 0.016 nanograms per liter. The EU average value recorded at official measuring points on surface water is 0.3 nanograms per liter, i.e. more than 18 times higher. Hormonally active substances are often effective even in very low doses.

According to Maack, the proposed PNEC value for diclofenac is 0.04 micrograms per liter, the measured average EU value is 0.4 micrograms per liter, i.e. ten times as much. The substance - 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 treating their cattle with diclofenac in the 1990s, a mass die-off of vultures began. 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.

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 Maack. "The skin is an effective barrier, that's also its job." When applied as an ointment, the majority of the active ingredient goes into the waste water when washing hands, showering or washing worn clothing. Only part is eliminated in the sewage treatment plants.

Maack is convinced that the ointments are often not medically necessary, with the exception of arthritis. “People should be much more aware of what they put into the environment when they are used.” In Sweden, diclofenac preparations to be applied to the skin are only sold on request and after advice on correct use and environmental effects.

Consumers who cannot do without diclofenac ointments should definitely pay attention to one measure: "Do not wash your hands immediately after application, but first wipe them with a cloth and throw it in the garbage," explains Maack. In general, leftovers and residues of medication should not be disposed of in the sink or toilet.

According to a study commissioned by the Federal Association of Energy and Water Industries (BDEW), the diclofenac inputs alone could cause environmental cleaning costs of up to 1.5 billion euros over a period of 30 years up to 2045. The main focus is on additional cleaning stages for sewage treatment plants.

The BDEW demands that drug producers participate in the financing of cleaning services. "We only create effective incentives to reduce emissions if manufacturers have to pay for the pollution they cause," Martin Weyand, BDEW Managing Director Water/Wastewater, was quoted as saying in a statement from mid-January.

The Association of Research-Based Pharmaceutical Companies (vfa) states: "Since medicines for the relief, healing and prevention of diseases are among the basic needs of the population, it is a task for society as a whole to remove the traces of medicinal substances from the water that result from the intake of medicines. that cause problems.” This responsibility for society as a whole also extends to financing.

The EU Water Framework Directive provides for a further purification stage, and more and more 4th purification stages are also being installed in Germany. They hold back trace substances, for example through so-called ozonation or activated carbon filtration. "Many active ingredients such as X-ray contrast media just rush through there," says Maack from the UBA.

Various other measures are therefore being discussed, such as an environmental compatibility traffic light as additional information for specialist staff. "Active ingredients like diclofenac should no longer be sold without a prescription," says Maack. In addition, there must be a fundamental change in the mentality in Germany when it comes to health issues, experts have been emphasizing for years: 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 condition and you don't have to do anything yourself," says Maack. If less reliance was placed on substances and more on behavioral changes, the amount of medication used would decrease in many areas.

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, according to the UBA painkillers, antibiotics, hormones, beta-blockers, contrast media and antidepressants are often found in water.

The problem will become more explosive: the baby boomer generation is reaching retirement age – and seniors 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. It's about blood pressure lowering drugs, painkillers, gastric acid blockers, anti-osteoporosis drugs, neuropharmaceuticals and a lot more.

In addition, the amounts of many substances in the environment add up from year to year. "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. They are often very poorly degraded in the environment and retain their biological effectiveness for a long time, as Maack says.

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. 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. On the one hand, many medicines would have to be storable for years at room temperature and without the exclusion of air, which requires chemical stability. On the other hand, substances in the human body that are particularly easily broken down or converted do not reach their target organs at all or cannot act there long enough.

More and more, more and more durable: What does that ultimately do? It is incredibly 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 and influence each other, as Maack explains. In addition, there are chronic effects and changes in the genetic material, which are even more difficult to track down.

Individual results prove something bad: In a Canadian lake, one of the key species among the fish stopped reproducing under the influence of the pill hormone ethinylestradiol - with consequences for the entire ecosystem, as Maack says. Antidepressants in a lake in Sweden, on the other hand, have changed the behavior of perch. "They left the flock more often, so they were at greater risk of being eaten."

The substances inevitably end up in drinking water and mineral water when water is withdrawn 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."

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