Health and Environment | Wipe instead of wash

The story of diclofenac, the active ingredient in pain gels like Voltaren, has essentially already been told. Even in low concentrations, diclofenac can harm aquatic life and birds. In trout, for example, it causes clouding of the cornea and bleeding. "Furthermore, the lamellae in the fish's gills thicken, making it more difficult for them to absorb vital oxygen." Gerd Maack of the German Environment Agency (UBA) reported on this again in detail at WeActCon 2025. The forum for sustainability in healthcare took place for the third time in Berlin this week. All possible interactions between health and the environment will be addressed here. The entry of drug residues into waterways is a major and as yet unaddressed problem.

The effects of diclofenac attracted particular attention when its use in veterinary medicine, especially in cattle, wiped out entire vulture populations in India. A few years ago, the first cases were observed in vultures in Spain, despite attempts by animal rights activists to prevent its approval for veterinary use in the EU. Diclofenac is extremely toxic to vultures, even in the smallest doses: a bird can die if it ingests just a few micrograms per kilogram of carrion.

But back to Germany: The relevant gels are widely advertised and used here – and are available without a prescription. Approximately 80 tons of diclofenac are consumed annually. Pain gels are particularly problematic, for several reasons. When applied externally, a maximum of six percent of the active ingredient actually reaches the desired target in the body; the skin acts as an effective barrier. Doctors now advise against their use for non-specific back pain. Voltaren should only be used for chronic arthritis.

While the release of diclofenac into the environment is comparatively high, it is not the only drug that is excreted after ingestion or whose residues are improperly disposed of. Among other things, biologist Maack warns of the potential environmental consequences if pharmaceutical production were to be relocated to Germany. In 2019, over 400 active ingredients were detected in surface waters in concentrations of one microgram per liter or more. Internationally, it is also considered certain that pharmaceuticals have an environmental impact. "This is supported by 2,000 publications on the subject from a wide variety of countries," says Maack.

Of the human medicines approved in Germany, 1,300 have environmentally relevant effects, according to the UBA biologist. Their mechanisms of action clearly show that antibiotics, for example, are effective against all bacteria, and that the hormonal systems of all vertebrates are similarly structured.

The Federal Environment Agency is now investigating the entry of medications, particularly into waterways, and researching their effects. It also wants to raise public awareness of the issue. This includes not only patients but also doctors, for example. Environmental information for newly approved medications has been mandatory at the European level for about ten years, and this information can also be found in various databases. However, this information has not yet found its way into the software of general practitioners, hospitals, or pharmacies. Scientists are currently working on a UBA project to develop a simple traffic light system that contains graduated warnings on the environmental impact of around 2,100 medications. Models for such a pharmaceutical index already exist in Sweden, Finland, and Scotland.

The fact that diclofenac is appearing in German waters at all is due to the use of pain gels: These are washed off in large quantities and thus end up in sewage treatment plants, where even new treatment stages cannot contain them . To prevent the cream and gel residues from subsequently having an undesirable effect on animals and plants, the UBA now offers information postcards, among other things. The slogan here is "Wipe instead of wash." Excess amounts should be wiped away with paper tissues, including from hands. The tissues should then be disposed of in the household waste, and any remaining amounts, including the tube, are likely to be disposed of there as well.

This presents another problem with the disposal of medications: there are no uniform regulations across the country. In addition to household waste, recycling centers or special mobile hazardous waste collection units are also possible. More detailed information can be found on the website https://arzneimittelentsorgung.de .