Tag: pharmaceutical waste

Categories : Environmental EffectsTags :

Wastewater Treatment Plants Are a Major Source of Pharmaceutical Pollution

On By ModernMedia

Common antidepressants, antibiotics and allergy drugs are being discharged into waterways, as conventional treatment fails to remove them

Photo by Myriam Zilles on Unsplash

Municipal wastewater treatment plants are ineffective at removing Prozac (fluoxetine) and other common pharmaceuticals in wastewater, causing the drugs to be discharged into lakes, rivers and streams where they pose a risk to aquatic organisms. Paulina Chaber-Jarlachowicz of the Institute of Environmental Protection – National Research Institute in Warsaw, Poland, and colleagues reported these findings in a new study published September 24, 2025 in the open-access journal PLOS One.

Most wastewater treatment plants break down organic compounds in wastewater using microbes, which are then removed as activated sludge. Existing research, however, suggests these methods do not remove pharmaceuticals effectively, causing them to be released into waterways. While some drugs do break down eventually, most persist in the environment, where they continue to be active, even at extremely low concentrations.

In the new study, researchers collected samples from six municipal wastewater treatment plants in Poland to investigate their ability to remove more than a dozen common pharmaceuticals. They measured the levels of drugs coming into the plant in the wastewater, determined how much is discharged to the environment in the treated water and sludge, and estimated the associated ecological risks.

The researchers found that all six wastewater treatment plants released pharmaceuticals into the environment. Only the pain reliever drugs naproxen (Aleve) and ketoprofen and the antihistamine salicylic acid were effectively removed during treatment.

For some pharmaceuticals, including the antidepressant fluoxetine (Prozac), the pain reliever diclofenac, and the anti-seizure drug carbamazepine, the treatment processes actually led to higher levels of the compounds in the discharged water than in the original wastewater. Fluoxetine and the allergy drug loratadine (Claritin) posed the greatest risk to aquatic organisms, due to their ability to disrupt hormone signaling and development at the levels seen in the treated water.

The new results add to the growing body of evidence demonstrating that conventional methods used by municipal wastewater treatment facilities are unable to remove many common drugs, making the plants a source of pharmaceutical pollution. These findings will lay the groundwork for further research into the inactivation of pharmaceutical compounds and their breakdown products in sewage and sludge.

The authors add: “The study’s findings demonstrated that municipal wastewater treatment facilities using conventional mechanical-biological processes (CAS) are ineffective at removing pharmaceuticals from wastewater. The annual emissions of pharmaceuticals to rivers from wastewater treatment plants in the study area amounted to at least 40Mg. Ketoprofen, sulfamethoxazole, carbamazepine and fluoxetine were identified as the primary contributors to the total mass load and emissions of pharmaceuticals.”

Provided by PLOS

Categories : Environmental EffectsTags :

Selenium Reduces Health Impact of Pollutant Mixtures

On By ModernMedia
Photo by Bill Oxford on Unsplash

A study in mice conducted by the University of Cordoba proves that exposure to mixtures of metals and drug residue exacerbates health impacts, and evaluates the positive effects of a diet enriched in selenium to reduce this harm.

People are exposed daily, through the environment and their diets, to external substances that can be harmful to their health. Metals and the residue of pharmaceuticals, for example, in high doses, contaminate water and food, creating mixtures where they can interact, with this increasing their individual toxicity.

Analysing the effects of environmental pollution on organisms is essential to develop regulations establishing maximum doses of these pollutants for people. But mixtures of pollutants pose unknown challenges as they may interact with each other.

To understand the health effects of exposure to these ‘cocktails of contaminants’, a team at the University of Cordoba, evaluated, in mice, the toxicity of a mixture of contaminants that is very common in the environment and that accumulates along the food chain: a combination of metals (arsenic, cadmium, mercury) and drugs (diclofenac, flumequine).

In order to determine how these compounds interacted with each other, “we studied the controlled exposure of mice to this mixture and analysed how it affects the proteins in the liver; that is, how their liver proteostasis changes when ingesting these mixtures of contaminants for two weeks,” explained Professor Nieves Abril, senior author of the paper published in Science of the Total Environment.

Their conclusion is negative: the cocktail effect synergises these compounds, doing increased damage to health when the compounds act together.

“We used a massive protein detection technique (shotgun proteomic), which allowed us to compare how the proteins of the group exposed to the mixture of contaminants were altered compared to the control group,” April explained.

Of the proteins affected, they selected 275 as sentinels to verify what was changing and, after computer analysis, they were able to determine the metabolic pathways that were altered and their consequences for health. These analyses revealed a disproportionate defence response having a contrary and harmful effect on the system.

The researcher stressed that “although these pollutants generated oxidation in the cells separately too, when they acted together we found that the oxidation was so intense that all the antioxidant defence responses were activated continuously, without deactivating them, which ends up doing damage and causing many proteins to stop working.” The analyses showed a sustained expression of the response mediated by NRF2, which is the regulator that sets in motion a good part of the antioxidant defences, which caused a reducing stress.

Selenium as hope

It’s not all bad news in the study, as selenium could be a way to reduce the damage caused by exposure to these pollutants. A third group of mice were given doses of selenium, a mineral often found in vitamin supplements found in pharmacies, and proteomic analyses showed relief from the molecular damage done by the pollutants.

Selenium itself is an oxidant, but in low doses it activates responses in a controlled manner, predisposing the body to better defence.

Source: University of Córdoba