Chronic Exposure to SSRI n Drinking Water: Public Health Implications under Water scarcity scenarios

Background

Selective serotonin reuptake inhibitors (SSRIs), such as paroxetine, fluoxetine and citalopram, are widely prescribed in Europe and are only partially metabolized, leading to their presence in drinking water. Climate change–related water scarcity is increasing water reuse, potentially concentrating emerging micropollutants. Chronic exposure to mixtures of bioactive compounds may pose a public health concern. This study aimed to assess exposure levels and related health risks.

Methods

A systematic literature review was conducted in major databases using predefined search strategies. Studies published in Europe were included in the last decade. Selection followed predefined criteria through title/abstract screening and full-text review. Data were extracted using standardized forms and qualitatively synthesized, focusing on occurrence in urban water matrices and risk assessment approaches, including cumulative exposure models.

Results

Mean concentrations were in the order of 100–10¹ ng/L in drinking water. Co-occurrence of multiple SSRIs was frequently observed. Cumulative assessments indicated a reduction in safety margins compared with single-compound evaluations. Chronic exposure models suggested that vulnerable groups may approach biologically relevant thresholds, while remaining below therapeutic levels. The hazard quotient (HQ) was <1, indicating adverse health effects are not expected for the estimated exposure in a healthy population, at the update level of knowledge. Findings are preliminary.

Conclusions

SSRI mixtures in drinking water represent a potential emerging issue, particularly under water scarcity conditions. Strengthening monitoring systems, improving treatment technologies, and integrating cumulative risk assessment into public health policies are recommended.

Key messages

• SSRIs in drinking water may pose emerging risks under conditions of water scarcity, making it necessary to reassess the risk evaluation.

• There is a need to improve the monitoring of SSRIs in drinking water and to carry out a thorough assessment of their potential impact on public health.