The 5T Paradox of Triclosan: From Toiletries to Toxic Trash, a Growing Threat to Humanity

Triclosan (TCS) persists as a contaminant of concern in the Anthropocene, despite regulatory actions. Environmental dissemination continues through wastewater effluents, biosolid application, and improper disposal practices. This narrative review synthesizes current evidence regarding triclosan's environmental fate, transformation pathways, and toxicological impacts, drawing upon findings from environmental chemistry, ecotoxicology, and molecular health sciences. Emphasis is placed on persistence in sediments and aquatic environments, transformation via photochemical and chlorination processes into more toxic derivatives, and bioaccumulation across trophic levels. Mechanistically, it interferes with endocrine signaling, mitochondrial function, lipid metabolism, and microbial community structure, thereby promoting antibiotic resistance and metabolic dysregulation. This review systematically connects exposure pathways to ecological disruption and potential human health outcomes, specifically endocrine and cardiometabolic effects. Integrating environmental monitoring data, mechanistic toxicology, and epidemiological trends, this analysis presents triclosan as a model contaminant for elucidating the long-term propagation of ecological imbalance and chronic disease risk by legacy antimicrobials in modern industrial societies.