Overview
- The CONICET–UNLP team sampled 16 pharmaceuticals across the Luján, Reconquista, Matanza-Riachuelo and the Del Gato, Maldonado, El Pescado and Espinillo streams, from rural headwaters to urban reaches.
- Rural waters typically contained two or three drugs, whereas urban stretches carried residues of nearly all targeted compounds.
- Carbamazepine was most frequent, followed by paracetamol, ibuprofen and atenolol, with paracetamol levels described as unusually high versus international reports.
- Patterns varied by season, with sildenafil far more prevalent in summer and respiratory drugs such as salbutamol rising in winter.
- Contamination peaked downstream of sewage-treatment discharges yet remained high where no sewers exist, indicating clandestine releases, septic systems and possibly leaking landfills as additional pathways.