Atrazine in fish feed and African catfish (Clarias gariepinus) from aquaculture farms in Southwestern Nigeria

Extensive use of atrazine as herbicide in crop farming in Nigeria may lead to its accumulation in fish feed ingredients or aquatic ecosystem from aerosol or by runoff resulting in its residue in aquatic animals. Atrazine residues were determined in fish feed and catfish (Clarias gariepinus) fillets from commercial aquaculture farms in Southwestern Nigeria by matrix solvent particle dispersion and quantification using an ELISA kit. The mean atrazine concentrations in feed and fish were about 1.3–1.5 μg/kg and 1.4–1.8 μg/kg respectively. Atrazine was mostly detected in catfish from Ogun State (91.3%) and feed from Lagos State (80.0%) with mean concentrations of 1.4 � 0.4 μg/kg and 1.5 � 0.5 μg/kg, respectively. Mean atrazine concentration in catfish samples from Lagos State was significantly higher (P < 0.05) than the mean concentration in catfish samples from Ogun State. This study showed that the Estimated Average Daily Intake (EADI) of atrazine in fish samples from the selected states were below the Acceptable Daily Intake (ADI) value of 6 μg/kg for herbicide residues and thus within safe limit but their presence in fish is a cause for concern