We are aware of the water pollution problems caused by plastics that fall into the sea. They come from different places: waste dumped on public roads, fishing nets, waste from ships and commercial cargo… These plastics, reduced to microplastics, are responsible for polluting the seas and poisoning marine species. Thus, each year, more than a million birds and more than 100,000 marine mammals die as a result of this invasion of plastics in the sea.
But there is a problem of similar magnitude that is beginning to gain prominence in the concern of scientists and biologists, and that is drug contamination in the water of rivers around the world.
A study published by PNAS on 258 rivers in 104 countries around the world shows that the presence of pharmacological pollutants represents a real threat to environmental and human health in more than a quarter of the places analyzed.
Environmental exposure to active pharmaceutical ingredients can have negative effects on the health of ecosystems and humans, and also represents a global threat to the achievement of the UN Sustainable Development Goals.
Pollution of rivers by drugs
The problem of antibiotics and drugs dumped into rivers has been known for a decade, although some regions such as South America and Africa had not been studied until now. The aforementioned study found that South Asia and South America concentrate the majority of rivers with high drug contamination around the world, topping the list of most polluted rivers in the cities of Lahore (Pakistan), La Paz (Bolivia) and Addis Ababa. (Ethiopia). In the case of Europe, the most polluted river is the Manzanares River while, in the United States, the southern city of Dallas has the most polluted river waters in the country.
Regarding the substances that are most found in the fluvial waters studied, anticonvulsants, antidiabetics and caffeine are some of the protagonists of this contamination.
How do drugs get into river water?
The discharge of drugs into the water is partly unavoidable, since it is a consequence of our own consumption. Our kidneys work to excrete “useless” substances from our body. There are studies that indicate that up to 90% of the medicine we take is expelled intact with the urine.
But not only humans are responsible for these events; farm animals, industrial discharges or drugs thrown away, also increase the pharmacological levels of the water.
Damiá Barceló, a member of the Higher Council for Scientific Research and director of the Catalan Institute for Water Research (ICRA), points out that “close to 20% of European citizens still flush medicines down the toilet, instead of taking them to pharmacies or collection of expired medicines”.
Antibiotics and other medicines.
The discovery of antibiotics in rivers was already a known problem years ago, although in this case, scientists determined that in more than 19% of the regions analyzed the presence of these drugs was so high that it could stimulate the development of resistant bacteria. These bacteria are considered by the WHO as one of the main threats against public health, and it is recognized as a “silent pandemic” that caused more than one million deaths in the world in 2019.
Because obviously the water we consume is subjected to purification and potabilization treatments that are responsible for nullifying the incidence of these toxins, but we must think about the species that live in these waters and that are the most realistic indicator of their level of health. . For example, algae and fish are hopelessly faced with the existence of these high levels of toxins that are detrimental to their existence.
In the case of antidepressants, some studies determine that marine animals can suffer a deterioration in their health due to the intake of these medications. Giovanni Polverino, an evolutionary ecologist at the University of Western Australia, recently stated that “The collateral effects of psychoactive pollutants in wildlife are of increasing concern. Psychoactive drugs target receptors in the human brain that are evolutionarily conserved throughout the animal kingdom; so it’s perhaps not surprising that they can affect non-target species.” In other words, the intake of antidepressants by these species can affect their ability to socialize, alter their eating patterns, migratory routes and even their mating. Research published in 2021 also revealed that crayfish exposed to antidepressants present in river waters become much more aggressive, hide much less and are therefore more vulnerable to predators. This certainly affects the food chain and the cycle of life.
The Drinking Water Treatment Plants or Stations (WWTP or WWTP) have means to remove the different contaminants that they may contain from the water. To do this, as we have already mentioned in previous blogs, they have numerous “pools” through which the water passes, and in each of them a contaminant is removed by reacting with some chemical substance that the plant pours into it. However, the huge amount of contaminants from medicines, or emerging contaminants (as they are called in some media) makes it very difficult or almost impossible to find reagents that completely remove them from the water we drink.
In this way, several studies affirm that the water that reaches the taps of our houses contains certain amounts of emerging contaminants or medicines that have not been able to be eliminated in the treatment stations, and that are harmful to health. And this circumstance, as indicated, could be even more serious in the future.
However, the water obtained from the Rain of Life atmospheric generators is unlikely to contain any of these emerging contaminants. For this reason, in addition to many others, its consumption is recommended for drinking and cooking.