Occurrence, distribution and environmental risk of 19 anthelmintic drugs in river water and sediment from the Jinjiang River, China†

This study explored the occurrence and distribution of 19 anthelmintic drugs (ADs) including the benzimidazole group, salicylanilide group, imidazothiazole group, tetrahydropyrimidine group, diphenylsulfide group, macrocyclic lactone group and hexahydropyrazine group in river water and sediment of the Jinjiang River in Sichuan, China, during summer and winter seasons. All targets were detected in river water (up to 74.64 ng L⁻¹) and sediment (up to 1701 ng g⁻¹) samples. The predominant ADs were benzimidazoles regardless of seasons and matrices, accounting for 43–82% of the total anthelmintic abundance. Obvious seasonal variation of AD concentrations in the two matrices was observed, which could be attributed to the seasonality of human and veterinary uses of ADs. Evident spatial variation (urban and rural areas) of ADs in winter was indicative of the influence of anthropogenic activities on the environmental concentration of ADs. Though benzimidazoles accumulated in the water and sediment with the highest concentration among all the ADs, macrocyclic lactones were of the highest risk to non-target organisms through ecological risk assessment, with an RQ_Ecotox value up to 2713. This work contributes to comprehensively assessing the contamination level, ecological level and transmission characteristics of ADs in the environment.