Emerging Contaminants and Superbugs

On emerging pollutants.

The improvement in the currently available analysis methods has allowed the detection of new pollutants in the environment whose presence is practically limited to traces, which until now remained hidden from our detection capabilities, which has increased concern about what we pour into our waters.

We are beginning to be aware that other compounds are found in our waters, which the scientific community has termed “emerging”, but which are old acquaintances of our environment. Compounds whose presence in water is disturbing because the concentrations that would be permissible, their persistence, or even their effects on living beings are not known.

In this way, in the last decade, compounds have begun to be studied in our waters, such as chlorinated paraffins, brominated flame retardants (such as the famous Bisphenol A), perfluorinated compounds, or metabolites derived from the degradation of chemical products such as pesticides, on which practically no one had studied until now their effects on the environment.

Its effects are beginning to be revealed to be very serious, and beyond its direct toxicity on systems and organs in living beings, carcinogenic effects, bioaccumulation, or even endocrine disruptions are beginning to be seen that could even affect the survival of certain species.

Between 12% and 64% of the male corcones studied in the Gernika, Pasaia and Deba estuaries, on the Basque coast, were intersex, and in most males, between 60% and 91% had vitellogenin in the liver, a protein that only appears in females.

Medicating rivers

Among the most worrying emerging pollutants are drugs, not only because of the familiarity of their use and disposal, but also because of their extent and the seriousness of their impacts.

Its presence in our waters is due not only to the discharge that occurs with its consumption in homes, but also to a series of other sources of origin such as:

• Livestock activities, which use drugs and antibiotics to treat animals, and which end up in the waters due to the infiltration generated to the soil when applying manure and other waste in agriculture.
• Aquaculture, which often uses fungicides, antibiotics and antiparasitic compounds extensively to treat fish crops.
• The same hospitals, an important source of discharging drugs and their metabolites into urban wastewater courses, destined for our treatment plants.
• The remains of drugs that, according to certain studies, 20% of consumers still throw down the toilet, a contamination out of pure irresponsibility that we all pay for.

This means that we have an approximate amount of 2 to 5 grams of drugs per 1000 inhabitants per day, of which our current treatment plants can perfectly account for analgesics and anti-inflammatory drugs, but they have problems assimilating the rest of the groups, which are usually between 20% and 60% effective in their purification, so that would mean between 0.5 and 1.5 grams per day of drugs discharged into the public channel per 1000 inhabitants.

A city like Madrid could account for approximately 4.7 kilos a day of medicines discharged into its rivers, and that's only taking into account the city's discharge.

It is not surprising that it is then possible to find traces of medications such as carbamazepine or even traces of caffeine and nicotine in the faucets in our homes.

Superbugs for the End of the World.

Among the harmful effects on health and the environment that are already being studied for these new emerging pollutants, there is one of them in particular, precisely linked to the use of drugs and biocides, which many scientists have described as the future Armageddon of humanity, although this time God seems to be able to take on a tiny size.

It's about the growth of drug resistance by bacteria in a battle between evolution and pharmacological technology in which pathogenic bacteria are winning with the invaluable help of the human being.

Within this battle, one of the main lines seems to be precisely the pollution of water and the current means available for its purification, which in many cases end up becoming an important system for the propagation of natural resistance in the environment.

In fact, the studies carried out so far show that 30% of the antibiotics present in wastewater are not eliminated in treatment plants and are discharged directly into the river, encouraging the appearance of resistance downstream of the treatment plants in bacteria present in the natural environment.

Despite this, the main problem is due to the ability of our current purification systems to spread resistance between existing bacteria in wastewater, becoming an “amplifier” of them, as well as the inability to guarantee the complete destruction of the enterobacteria found in this environment.

This poses not only a risk to the workers of the treatment plant itself, or to those who move the sludge from them, but also to public health itself, especially in those cases in which the water is reused or used for recreational or bathing purposes downstream of the purification system.

This has already been demonstrated by several studies that have discovered superbugs in water discharged from treatment plants that are resistant to most antibiotics, even the most advanced antibiotics, also called third-generation antibiotics, used precisely to combat these resistances in the hospital environment.

It is estimated that in the United States, superbugs already kill about 23,000 people a year, and are present in at least 2 million diseases, according to official data, a trend that seems to rise to 25,000 deaths in the case of Europe, two-thirds of them due to superresistant gram-negative bacteria.

The vast majority of these deaths occur in hospital-acquired infections, but the problem could begin to transcend these types of infections, lying behind some of the most difficult to treat infections, and becoming a problem of global reach and distribution.

This trend could lead us to a serious situation, in which old minor illnesses and minor infections, which until now were treated in a simple and effective way, become fatal diseases without available treatment or require aggressive hospitalization treatments.

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