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This page aims to explain in simple terms, and for the broad public, some key facts about human pharmaceuticals in the environment and in drinking water.


Pharmaceuticals are substances that can be found in prescription medicines and over-the-counter therapeutic drugs: high blood pressure medicine, pain relief tablets, cough syrup, eardrops, contraceptive pill, vaccines, the list goes on... Despite our limited current understanding of this emerging environmental issue, the scientific community tends to agree that we should already explore ways of limiting the input of PPs into the environment, thus anticipating action needed in the future.


1. Human health risks

2. Effects on wildlife and the environment 

3. Dispelling some common myths

4. What can we do?




1. Human health risks


The detection of pharmaceuticals in the environment and in drinking water has been the subject of both significant scientific research and journalistic coverage. Trace concentrations of pharmaceuticals (naturally excreted by the human body after consumption, or disposed of unsafely e.g. via toilets) travel through the raw sewage and wastewater effluents, reach environmental waters, and sometimes make their way into drinking water.


Pharmaceuticals occur in drinking water at concentrations generally more than 1000-fold below the lowest clinically active dosage; there is broad scientific consensus that they are therefore very unlikely to pose risks to human health. The World Health Organization, for instance, reached this conclusion in a review of the topic in 2011. Nonetheless, knowledge gaps exist in terms of assessing the risks of long-term exposure to low concentrations, and the combined effects of mixtures of pharmaceuticals. Future research in these areas may be beneficial, particularly to characterize the risks for sensitive subpopulations, such as embryos and the elderly.


However, it is not only about human health: there are grounds for concern regarding the environmental impact of pharmaceuticals. It is also important to remember that it is possible for everyone to contribute to reduce the presence of pharmaceuticals in the environment.



2. Effects on wildlife and the environment


Although the levels of pharmaceuticals present in the environment are too low to be considered a risk to human beings, their presence raises questions, particularly about the potential for low concentrations of pharmaceuticals having long-term (chronic) effects on aquatic life.


To date, two cases of direct cause and effect have been identified in which pharmaceuticals affected wildlife. The first is that of the anti-inflammatory diclofenac, used as a veterinary drug for cattle. Tens of millions of vultures in Asia died as a result of feeding on the corpses of treated cows. Another clear effect is the feminization of male fish, reported in many countries; the oestrogen derivate ethinyl estradiol, in combination with other hormones or hormone‑mimicking substances (non pharmaceuticals), is considered responsible for this effect (Kümmerer & Hempel (Eds.), 2010; EEA 2010).


In spite of only two cases of direct cause and effect, there is concern regarding the possibility of other effects on wildlife, current or future. This is due to the large number of pharmaceutical compounds, the fact that they are designed to be biologically active, and the knowledge gaps concerning them. Various factors can amplify risks or disguise their impact. For example, effects on smaller organisms, such as species of small snails, may be unnoticed due to their size. Compounds most frequently mentioned as problematic are antibiotics, antiparasitics, antidepressants, and anticancer medications.

The concern is sufficient to have taken up a few pharmaceutical compounds in discussions setting maximum concentration limits for Europe’s rivers and lakes.



3. Dispelling some common myths


Many myths surround the presence of trace amounts of pharmaceuticals in drinking water. Pharmaceuticals are very rarely detected in treated drinking-water, and when they are, their concentration is extremely low. In the words of the World Health Organisation, “appreciable adverse impacts on human health are very unlikely at current levels of exposure in drinking-water” (WHO, 2011).

However, the subject of pharmaceuticals has often been misrepresented or overdramatized in the media. Various articles present inaccurate information or aim for sensationalism. Most of the misconceptions are related to human health; many relate to the effects on sexuality.


The following points show some of the most frequent myths on the topic, which have no basis in reality.


Enough tap water will cure your headache

The difference between the concentration of any pharmaceutical in a liter or two of water (the amount likely to be drunk each day by an adult) and the amount of that drug taken therapeutically by a patient could easily be a million-fold. Even if people drank water contaminated with very low concentrations of pharmaceuticals throughout their entire life, the total amount of the most pharmaceuticals ingested may not reach the amount of a single therapeutic dose (Kümmerer & Hempel, 2010).


Excessive man breasts caused by female hormones in the drinking water

Reports of an increasing number of men suffering from gynaecomastia (excessive breasts) is often wrongly believed to be caused by female hormones in the drinking water. In reality, this condition is caused by other factors: 1) pubertal gynaecomastia, common in boys, sees breast tissue grow due to hormonal imbalance; 2) breast growth can be side effect of drugs used to suppress prostate cancer; 3) genetic conditions like Klinefelter's Syndrome. Other causes include obesity and anabolic steroid use.


The drop in male fertility is caused by female hormones in the drinking water

The claim that the drop in sperm count may be caused by men ingesting synthetic estrogen in the drinking water originating from the contraceptive pill is not substantiated. Scientific evidence to back up this assertion has yet to emerge.The sperm controversy is rather caused by a host of “gender-bending” chemicals from a wide variety of substances that have become ubiquitous in daily life. Alarm about chemicals affecting human health has been raised many times by environmental groups since the first case of feminizing of fish was discovered a few years ago. As it is the case for fish, the effects observed in men cannot be strictly linked back to pharmaceuticals. Endocrine disruptors are contained in other products we consume.


Babies being born girls when they should have been born boys

The claim that the normally ratio of boys born for every girls is slipping due to the presence of female hormones in the water is also uncorroborated. As for defects observed on baby boys, also wrongly claimed to be caused by female hormones, they also find root in the array of chemicals that surround us. Gender-bending chemicals are considered likely to account for a proportion of birth defects in baby boys and the testicular cancer and fertility problems the boys may suffer later in life.



Selected press stories:

4. What can we do?


PHARMAS will help enable different actors play their role in contributing to one of this project’s overall goals: reducing the presence of pharmaceuticals in the environment. Different actions can help reduce their presence. The following are important actions that can be performed by all of us in daily life.Other initiatives are challenges for other social actors, e.g. scientists, industry, and policy makers.


Use medicines responsibly

Using medicine responsibly is important to safeguard human health and that of the environment. Patients should comply with their doctor’s recommendations and consume pharmaceuticals only when necessary; this also means avoiding self-medication. Medicines that are no longer necessary or that have expired should be brought back to the local pharmacy to be properly disposed of. This also prevents accidental intake, for instance by children.


Dispose of unwanted and old medicines the right way 

Medicines should not be flushed down the toilet or the drain nor should they be thrown in the trash bin with the rest of the regular household waste. In order to have their desired effect on the human body, pharmaceuticals are pretty stable compounds. When we flush the toilet or turn on the tap, the water that goes down the drain flows towards the sewage treatment plant to undergo treatment. The stability of the molecules can hinder their biological degradation in conventional sewage treatment plants; many pharmaceuticals are only partially removed, and others not at all. Pharmaceuticals will then travel to the rivers and lakes from the effluent of sewage treatment plants, where they can have an effect on aquatic organisms. Eventually, the stable molecules can then make their way into the groundwater and finally - via drinking water - back to humans.


The disposal of pharmaceuticals with the domestic solid waste raises similar concerns. Pharmaceutical compounds that end in landfills can seep through the soil (with the landfill leachate) and contaminate groundwater if the landfill is not properly sealed. Additionally, pharmaceuticals in waste bins are a potential risk for children and pets who might reach them. Only when the domestic waste is burnt is it a good option to dispose pharmaceuticals in house garbage, but this practice is not widespread in the EU; disposing waste in landfills is the more common approach.


The EU legislation requires Member States to set up take back programmes for unwanted and old medicine. In many cases, these official collection points are located in pharmacies.



Links to some take-back programmes in EU countries