Detection of chlorpheniramine in tissues of Oreochromis niloticus in a river impacted by domestic sewage in Cubatão, SP

Abstract

The increasing environmental degradation in coastal ecosystems, linked to the discharge of domestic sewage, has led to the introduction of various contaminants into aquatic environments, including pharmaceuticals such as chlorpheniramine, a widely used antihistamine. This study aimed to qualitatively detect the presence of this compound in O. niloticus tissues collected from the Santana and Paranhos rivers, located in the municipality of Cubatão, São Paulo, an area severely impacted by untreated sewage from surrounding communities. Muscle and liver samples were analysed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Chlorpheniramine was detected in fish tissues, confirming the contamination of the aquatic ecosystem by pharmaceuticals derived from anthropogenic activity. This is the first report of this antihistamine in fish from a mangrove river in Cubatão, highlighting the urgent need for monitoring and proper management of pharmaceutical residues in aquatic environments.