Occurrence of insecticides, fungicides, and herbicides in household drinking and irrigation water in an intensive floriculture region of Ecuador

Pesticides are widely used in agriculture, floriculture specifically, posing significant ecological and health risks. Limited research has been conducted on the presence of neonicotinoid insecticides (NNI) and atrazine, in drinking and irrigation water in agricultural regions of Latin America. This study describes targeted and non-targeted analysis of concentrations of pesticides in drinking and irrigation water sampled in 2022 and 2023 in an industrial floricultural region in Pedro Moncayo, Ecuador. In targeted analysis, we found NNI in treated drinking water in 20.5% of household tap water samples (8 out of 39), in a community well, and in 57.7% of irrigation water samples (n = 15 out of 26). Imidacloprid and thiamethoxam emerged as the most frequently detected NNI in drinking water. Atrazine was detected in two household taps and one well. In exploratory non-targeted analysis, we found 63 compounds, including insecticides, herbicides, and fungicides, including azoles, in drinking and irrigation water samples. Fungicides accounted for 59% of all compounds (37 out of 63) detected. Intense pesticide use in floriculture in proximity to residential areas and aging piped water systems may allow pesticides to leach into treated drinking water pipes and irrigation water. The presence of a wide range of pesticides, especially NNI and fungicides (azoles, specifically), in drinking and irrigation water poses health risks to community members.