Aquatic ecosystems are increasingly polluted as a result of human activities and, although thanks to treatment plants we can control some of the waste that ends up in rivers, seas and groundwater, many others escape and disperse. Due to this, it is necessary to analyze what are its effects on organisms and on the functioning of ecosystems.
Although much of the aquatic pollution comes from industrial and agricultural activities, there are numerous products of daily use that also end up in the water. A few years ago we already documented in an extensive report how various studies have located a wide variety of drug remains in the water of rivers and seas.
In 2014, a study carried out at the University of the Basque Country found feminization symptoms in a species of marine fish as a result of exposure to endocrine disruptors. Now, a team from the same university has just published a study in the journal Environmental Toxicology and Chemistry in which it detects that certain drugs and sunscreens pollute the water, accumulate in fish and cause side effects.
“The concentration of this type of pollutant is worrying, because consumption is increasing and in the treatment plants we are unable to eliminate them, they reach the fish and are changing their metabolism,” says Haizea Ziarrusta, lead author of the work. “We do not know to what extent that will influence at the individual level, and the problem could reach population levels. As we pollute the sea, that is, as pollutants increase, the situation worsens, and it is necessary to know if there is a risk that the pollutants accumulated by fish reach humans ”.
The team of researchers carried out different experiments with gilthead sea bream (Sparus aurata ) to evaluate the bioaccumulation of amitriptyline (antidepressant), ciprofloxacin (antibiotic) and oxybenzone (ultraviolet filter used in many sun creams) and their distribution in the tissues of these animals. “Furthermore, we have investigated the biotransformation of these pollutants and characterized their degradation products; finally, we have investigated the changes caused by these pollutants at the molecular level, analyzing the metabolism of the fish ”, explains Ziarrusta.
Effects on metabolism
And, although the risk of accumulation of these pollutants in fish and other species is known, it is necessary to investigate in depth what happens when they enter your body: how they accumulate, distribute, metabolize and eliminate. “The lack of knowledge about the transformation and biodegradation of drugs and personal care products can lead to underestimate the true effects of exposing fish to these pollutants ” explains the researcher. “These by-products, those derived from transformations and metabolites, can be as dangerous or more dangerous than their precursors.”
For example, the scientists analyzed the alterations that occurred in sea bream after exposure to an environmentally relevant concentration of amitriptyline for 7 days. The results revealed the appearance of oxidative stress in both the brain and the liver , as well as other alterations in energy metabolism that had not been documented to date.
The pollutants studied “produce secondary effects in their plasma, brain and liver, because they interfere with their metabolism, and can even affect them at the organism level,” adds Ziarrusta.
There is still much work to be done: “the analytical approaches we have developed can also be used to investigate other types of pollutants and species; in this way, decisive information can be gathered to assess environmental risks and establish new regulatory measures ”, concludes the researcher.
Reference:
Ziarrusta et al, 2019. Amitriptyline at an environmentally relevant concentration alters the profile of metabolites beyond monoamines in gilt‐head bream Environmental Toxicology and Chemistry DOI: 10.1002/etc.4381
