Researcher detects antidepressants in the Tietê basin – 12/26/2023 – Environment

With the help of 40 researchers from seven public universities and the Butantan Institute, biologist and professor at USP (University of São Paulo) Luis Schiesari conducts an unprecedented mapping of life and water quality in the Tietê river basin.

The research he coordinates scans the presence of medicines — such as antidepressants —, pesticides, recreational drugs, bacteria and viruses in 52 small river basins that feed the Tietê River in the metropolitan region of São Paulo.

The same study also compares the morphology and behavior of different species of fish, amphibians and invertebrates that live in these habitats. The idea is to understand how advances in urban coverage impact aquatic ecosystems and, from there, devise strategies to protect them.

The research is financed by USP, Fapesp (São Paulo State Research Support Foundation) and CNPq (National Council for Scientific and Technological Development).

The research group published its first article, signed by professor Ricardo Taniwaki, from UFABC, in November. The work showed the presence of Covid virus RNA in monitored rivers and streams, particularly in those with medium urban coverage and poor basic sanitation.

Also in November, Schiesari submitted a new article to the journal “Science of Total Environment” with data indicating the presence of antidepressants in the Alto Tietê basin — a stretch of the river that runs from Salesópolis (SP) to Pirapora do Bom Jesus (SP).

The scan included 200 drug molecules and was carried out in partnership with professor José Luiz da Costa and biomedical scientist Aline Franco Martins, both from the Faculty of Pharmaceutical Sciences at Unicamp (State University of Campinas).

According to the data submitted, which will still undergo peer review, 93% of the basins with some level of urban coverage contained one to eight different antidepressant molecules — venlafaxine, bupropion and sertraline were the most frequent.

These molecules can reach collection points through direct disposal or through feces and urine discharged through clandestine connections into rivers.

Brazilian law does not determine a maximum value for the concentration of pharmaceuticals in treated water and, in general, treatment systems are not effective in removing them from the water. Even metabolized, the molecules can still exert a pharmacological effect on living beings.

“Although they are not expected to have an acute effect, by definition they are molecules designed to have a biological effect and therefore can have unanticipated impacts on organisms and environments”, Schiesari tells Sheet.

Although the effects of antidepressant accumulation on aquatic life are not yet fully understood, research published in recent years indicates that they can affect development, reproductive behavior and hunting patterns of fish and other animals.

Sought by the report, Cetesb (Companhia Ambiental do Estado de São Paulo), a government agency responsible for monitoring water quality in the state of São Paulo, says it monitors residues of anti-inflammatories and contraceptives in the water of creeks and streams in the state .

Also contacted, Sabesp (Companhia de Saneamento Básico do Estado de São Paulo), responsible for treating water and sewage in the metropolitan region, stated that the treatment stations meet the standards of the legislation of the Ministries of Health and the Environment.

With a degree in biology from USP, a master’s and doctorate in ecology from the University of Michigan (USA), Schiesari has already conducted fieldwork in the central Amazon, savannah and Atlantic forest.

For more than a decade, however, he has dedicated himself to studying life in environments altered by human action, such as pastures, crops and cities. Therefore, he defines himself as an ecologist of modified environments.

“The preserved environment is irreplaceable in terms of ecosystem services and biodiversity, but it is possible to design human structures with less impact”, says the scientist. “To do this, we need to understand modified ecosystems.”

At the end of November, the report from Sheet accompanied Schiesari in two basins analyzed by the research project, called “Ecology of Modified Environments”.

The first is on the Rio Grande, in the Nascentes de Paranapiacaba Municipal Park, in Santo André (SP). It is what the professor calls a reference: it is entirely preserved and serves as a basis of comparison for the study of degraded streams.

The second, on the outskirts of the city of Mauá (SP), is almost completely integrated into the urban fabric. At the point visited by the report, the stream has a straightened path and a retaining wall on both banks. In addition, it receives garbage and sewage through clandestine connections.

According to Sabesp, 660 thousand people live without sewage collection in the city of São Paulo — a count that, according to experts, is underestimated because it excludes irregular housing. It is this sewage, discharged irregularly into streams on the outskirts, that flows into the Tietê and feeds the river’s pollution patch, now 160 km long.

Schiesari emphasizes that basic sanitation is the first step towards recovering urban rivers as ecosystems, but it is not a silver bullet.

It is also necessary to review strategies used in the past, such as course corrections, concreting banks and backfilling, he says. According to data from São Paulo City Hall, 280 rivers in São Paulo are now underground.

“The most common engineering solutions were designed to guarantee hydraulic efficiency for rivers, and not to preserve them as ecosystems”, says the professor.

In preserved environments, rivers and streams have curves, rapids, pools and rocks that guarantee the survival of a series of specialist organisms, those that live only in specific environmental conditions.

“Rivers straightened and made concrete by human action allow only very tolerant species, which are the minority, to survive”, explains the ecologist.

Schiesari says that, to increase the quality of these streams as ecosystems, it would be important to ensure the maintenance of bank vegetation, which controls erosion and serves as food and shelter for living beings.

“Another level of intervention would be the reconstruction of water beds, with increased structural complexity, and, in extreme cases and depending on very careful studies, the reintroduction of native species”, he concludes.

In March this year, the Tarcísio de Freitas (Republican) administration announced R$5.6 billion for initiatives to recover and clean the Tietê River. The program foresees, among other measures, desilting the riverbed, increasing basic sanitation coverage and recovering the vegetation on the banks. There is no plan for restructuring the already altered watercourses.

“An aquatic ecosystem with hundreds of contaminants flowing, volatilizing, raining and being breathed in is not good for humans”, summarizes the professor when asked about the importance of preserving river ecosystems. “The same factors that condition the well-being of organisms condition human well-being.”