"Water is the material of life. It is matrix, mother and medium. There is no life without water." With these words Albert Szent-Gyorgyi, Hungarian physiologist, reminded us of the importance of water at the beginning of the 20th century. Water pollution is a phenomenon that has grown rapidly in recent decades: from industrial to military, from plastic to agriculture, from the so-called 'urban' to thermal pollution; these are just some of the pollutions that, day after day, are destroying our ecosystem.

Little known, but one of those closest to everyday life, is pollution from medicines (including antibiotics), drugs of abuse, chemicals and pesticides which, once dispersed in the water, reach the seas, rivers, basins and aquifers, affecting the balance of entire ecosystems. It is important to remember that water purification plants are NOT always able to eliminate these substances in their entirety, thus making this environmental problem a fundamental one to study, analyze and solve.

Water is a good to be preserved; research and awareness must become beacons for a better future. In our country we are well aware of the problems of drought and water loss and we must defend the blue gold, the source of life.

Our territory is not saved from water pollution; the Milanese area is home to a high concentration of pollutants, which can be traced back to drugs of abuse, medicines and chemical products for personal care. The "Mario Negri" Institute for Pharmacological Research, together with the Norwegian Institute for Water Research and the SCORE network, conducted the study "Monitoring the consumption of drugs of abuse by analyzing urban wastewater"¹ from which, through the analysis of the waters of the rivers that flow through the Milan area (the Olona, the Seveso and the Lambro), the sewage waters produced by the city of Milan and those of the aquifers from which drinking water is extracted, it emerged that every year Milan discharge into metropolitan waterways:

In addition to Italy, the problem of water pollution is developed in the rest of the world as well. The study "Pharmaceutical Pollution of the World's Rivers", published in Proceedings of the National Academy of Science, led by a team of researchers from the University of York, examined 258 rivers around the world, from the Mississippi to the Amazon River, for measure the presence of 61 drugs. The result was concentrations at potentially toxic levels in more than a quarter of the locations studied. The results of the sampling show that the problem of drug pollution affects rivers on all continents. Low- and middle-income countries, which are least equipped with adequate infrastructure, are the most affected. The most polluted regions are in fact those of sub-Saharan Africa, South America and South Asia. In general, the elements and human activities associated with greater contamination are the construction of landfills along the river banks, the inadequacy of wastewater management systems and in the design and production of drugs.

'One of the main environmental problems in the world' reads the report of the Joint Research Center of the European Commission (JRC, 2017) and another European report, the Chemicals in European waters (European Environmental Agency, 2018), describes the phenomenon of 'the cocktail effect', dangerous with a 'One Health' logic, i.e. the synergy between human, animal and environmental health.

WWF Italy raises the alarm by recalling that every year in the world 220 billion tons of chemicals are released into the environment and that globally over 100 thousand toxic substances are on the market. In Europe alone, in 2020, over 200 million tonnes of chemicals hazardous to human health and over 50 million tonnes hazardous to the environment were produced and used.

Of the 9 million deaths attributable to pollution recorded in 2019, 5.67 million would be the result of air pollution, responsible for the highest number of deaths. Water pollution, on the other hand, was responsible for 1.36 million premature deaths. Lead caused 900,000 deaths, while 870,000 people died from problems related to other toxic substances.

Although this type of pollution is barely perceptible to the naked eye, it is very dangerous and harmful to the health of ecosystems, including the human species. We want to focus on the dangers of some pollutants, in particular those that we would like to remove through constructed wetlands (sources listed numerically at the foot of the page):

Diclofenac

The nonsteroidal anti-inflammatory drug diclofenac is one of the commonly used and frequently encountered drugs in water bodies. Active ingredient of Voltaren, it is used a lot in intensive animal farms, especially pigs. A toxic effect on plants and algae, in particular an algaecide activity², is attributed to it.

Carbamazepine

Carbamazepine is an anticonvulsant drug; it works by reducing electrical activity in the brain; it is used alone or in combination with other medicines to control some types of seizures associated with epilepsy. It also finds application in the treatment of neuralgia and psychiatric disorders. It has been verified that significant concentrations of the drug in the environment have enriched series of genes that regulate the development and function of the nervous system in fish species. Altered gene sets have also been associated with potential neurological disorders, including autism spectrum disorders (ASDs). Furthermore, the drug molecule is transmitted from the mother to the embryo³.

Sulfamethoxazole

Sulfamethoxazole is a very common broad-spectrum bacteriostatic antibiotic. Its residue is often found in water and can therefore bioaccumulate in the brain of aquatic organisms via the bloodstream. Some studies have shown that this antibiotic induces toxicity of the cerebral capillaries in some animal species, such as in the Zebrafish⁴.

Ciprofloxacin

Ciprofloxacin is a synthetic antibacterial drug belonging to the quinolone class. More precisely, ciprofloxacin is a fluoroquinolone. It has a bactericidal action, i.e. it is able to kill bacterial cells. Its level of concentration in surface water is associated with the frequency of human activities; found in farmland and ponds, can cause medium to high risk to algae and bacteria in aquatic systems⁵. The drug promotes resistance of bacteria to antibiotics⁶.

Glyphosate

Glyphosate is a nonspecific organophosphate pesticide, which finds wide application in the protection of crops from weeds. Its high solubility in hydrophilic solvents, especially water, and high mobility allow for rapid leaching of glyphosate into soil, leading to groundwater contamination and accumulation in plant tissues, thus complicating herbicide elimination. It therefore induces the reduction of crops, low quality agricultural products, the deterioration of soil fertility, contributing to water pollution and consequently threatening human and animal life⁷.

Chlorpyrifos

Chlorpyrifos is a broad spectrum chlorinated organophosphate pesticide used for the control of a variety of insects and pathogens in crops, fruits, vegetables as well as households and various other places. Pesticide toxicity has been associated with neurological dysfunction, endocrine disorders, and cardiovascular disease. It can also induce developmental and behavioral abnormalities, hematological malignancies, genotoxicity, histopathological aberrations, immunotoxicity, and oxidative stress, as evidenced by animal modeling. In addition, eye irritation and dermatological defects due to the toxicity of chlorpyrifos have also been reported. The mechanism of action of the pesticide involves blocking the active sites of the enzyme acetylcholinesterase (AChE), thus producing adverse effects on the nervous system⁸.