Concentrations of pesticide residues in fish tissue are below detectability in the Menoua River (West Cameroon).

Fresh water fish are an important source of animal protein in the diet of Africans, but despite their exposure to pollutants, particularly pesticides, in rivers and streams, there is scarcity of data on fish accumulation levels of these pollutants. The concentrations of 259 pesticide residues were measured in two highly consumed fish species (Clarias gariepinus and Oreochromis niloticus) sampled from the Menoua River, in the West Region of Cameroon. The pesticide residues were determined using QuEChERS (Quick Easy Cheap Effective Rugged and Safe) followed by gas chromatography-mass spectrometry. The results obtained show that concentrations of all pesticide residues in the samples were lower than 0.01 mg/kg and therefore below the WHO maximum residue limit for the evaluated pesticides. However, the non-detection of pesticides in the studied fish does not call for complacency as this does not imply a complete absence of pesticides. Low levels of pesticide mixtures have been shown to result in combined effects that are synergistic. There is therefore a need for further research on the possible biological effects, including endocrine disruption, growth and reproduction inhibition on the fish populations as well as dietary risk assessment on the local population. The contamination of water, sediment and other aquatic resources also remains a question for future research.