# Occurrence and temporal changes of pharmaceuticals in the Warta River in Poland during and after the COVID-19 pandemic

## TL;DR

This study shows how pharmaceutical levels in a Polish river changed during and after the pandemic, reflecting shifts in public health and behavior.

## Contribution

The study links pharmaceutical concentrations in a river to pandemic-related societal behavior changes, including mental health and healthcare access.

## Key findings

- Pharmaceutical concentrations near treated sewage outflow increased significantly during the pandemic.
- Lockdowns correlated with higher levels of psychotropic and preventive drugs, indicating mental health impacts.
- Post-pandemic psychotropic drug levels remained high, suggesting ongoing mental health deterioration.

## Abstract

This research aimed to assess the impact of the COVID-19 pandemic on pharmaceutical concentrations in surface water. The Warta River (western Poland) was studied at points upstream and downstream of the treated sewage outflow. Ten pharmaceuticals were analyzed in 12 sampling campaigns during the pandemic (February 2020 - April 2021), and 3 during the post-pandemic period (November 2024 - January 2025) to assess their long-term impact. The results revealed a significant increase in pharmaceutical concentrations near the outflow of treated sewage (range 1.53–20.47 µg/L), confirming that it is the main source of these micropollutants in the environment. Moreover, the concentration increase in the river, overlapped with successive waves of the COVID-19 pandemic. This made it possible to identify patterns of society’s behavior. During lockdowns, preventive and psychotropic drug concentrations increased in the river. These indicate that higher consumption of these pharmaceuticals maybe associated with worse mental well-being and a desire to protect against the virus. However, the concentrations of antibiotics and cardiological drugs decreased, which was linked to more difficult access to doctors and protection from the virus by avoiding the health center. During the post-pandemic period psychotropic drug concentrations increased significantly, suggesting a significant deterioration in society’s mental health.

The online version contains supplementary material available at 10.1038/s41598-025-14568-x.