Bioaccumulation and toxicity of terbuthylazine in earthworms (Eisenia fetida)

Terbuthylazine is an effective and widely used s-triazine herbicide. However, limited data exists on its toxicity and bioaccumulation in earthworms (Eisenia fetida). In this study, we investigated the bioaccumulation, anti-oxidant enzyme activity, detoxification enzyme activity, and DNA damage in earthworms when exposed to terbuthylazine. The results indicated that terbuthylazine in soil had low bioaccumulation in earthworms and the biota-soil accumulation factors of terbuthylazine declined with an increasing soil terbuthylazine concentration. In the enzyme activity assays, the superoxide dismutase (SOD), catalase (CAT), and glutathione-S-transferase (GST) activities showed upward trends when compared with the control. The carboxylesterase (CarE) activity increased on day 21. The 8-hydroxy-2-deoxyguanosine (8-OHdG) content, a DNA damage bioindicator, was higher than that of the control on day 21. Combined with the integrated biological response index version 2 analysis, these results can provide a comprehensive evaluation of the toxicological effects that terbuthylazine has on earthworms and soil ecosystems.