Large amounts of medicinal drugs end up in the Baltic Sea

It was not until the 2010s that pharmaceuticals were perceived as a significant environmental pollutant. Even though medicines have been used and released into the environment for decades, this problem has only recently come to light.


Medicines are harmful because they are synthetic compounds which do not occur naturally in nature. They are also hazardous because they are designed to affect their subject even at low concentrations. This also holds true for organisms which are not the medicine’s primary target.

Medications in a domestic medicine cabinet.

Wastewater treatment plants are not designed to remove drug residues

Medicinal drugs enter the environment from pharmaceutical factories, hospitals, veterinary medicine, and human use. Much of the drug load comes from the urine and faeces of humans and animals.

Drug residues are transported to wastewater treatment plants which are not designed for the removal of medicinal drugs. Purification plants act selectively on how they deal with medicines. Some drugs decompose, others bind to the sewage sludge, while yet others pass directly through the treatment plant and end up in the sea.

An infographic about medicines in the home.
Medicinal products are released into the sea and have an impact on marine animals. Medicines end up in waterways because urban wastewater treatment plants are not designed to remove such harmful substances. The adverse effects of drugs in waterways are not yet known. Take outdated or unnecessary medicines to your pharmacist for disposal. Do not throw them down the toilet or into the rubbish bin. Some drugs pass into the waterways through the wastewater treatment plant and adversely affect aquatic organisms. Source: SYKE. Illustration: Kaskas Media Oy.

Analgesic ointment, painkillers, heart medicine, antiepileptic drugs - all occur in marine biota

The most common drug residues derive from anti-inflammatories, cardiovascular medicines, as well as drugs which act on the central nervous system. Such medicinal drugs appear not only in the water but also in the tissues of aquatic organisms.

For example, several well-known medicinal drugs, including diclofenac, ibuprofen, and ketoprofen have been detected in communities of blue mussels growing near the discharge pipe of the wastewater treatment plant at Viikinmäki, in Helsinki.

The proper recycling of medicines is important

Outdated or otherwise unused medicines should always be recycled correctly. They should not be disposed of in the toilet or in the rubbish. If the drugs are flushed down the toilet, they will likely end up in waterways after simply passing through the wastewater treatment plant.

Medicines for disposal should be taken to the pharmacy. In this case, the medicines will be disposed of correctly and without any burden on the environment.

Very little is known about the effects of drugs on marine life

There is a great deal of information about the volume of medicinal drugs produced, as well as their uses. By contrast, information on their concentrations in water bodies depends on the drug in question. Even less is known about their fate and their effects on the environment.

There are currently no guidelines for the environmental monitoring of pharmaceuticals. There are also no drug concentration limits for treated wastewater.