Pesticide usage has contributed to increasing food production; it has also caused them to be found in ecosystems inducing adverse effects on biota. Fish are the most abundant and diverse vertebrates in the world and are of great importance both economically and ecologically. Some fishes are indicators of the environmental quality of aquatic ecosystems and provide insight as to how pollutants might influence public health. The tilapias species can be considered biomonitors because they present little displacement representing the contamination level of a site. This study aimed at three goals: (1) to determine the concentration of 20 pesticides in tilapia muscle in the Ayuquila-Armería basin, (2) to describe the spatiotemporal variation of analytes and (3) to evaluate the risk of consuming contaminated fish. The presence of 11 pesticides was determined. Ametrine, glyphosate and malathion concentrations showed significant differences by season. The risk assessment showed that the consumption of tilapia muscle from the Ayuquila-Armería basin does not represent a risk for the population. Diazinon concentrations were relatively low compared to the other pesticides concentrations, but its toxic characteristics were the ones that most negatively influenced the risk assessment. The results obtained are relevant from the social and economic points of view.
Keywords: Pesticide pollution; bioindicator; food contaminant; resident fish; risk assessment.