Translocation, distribution, and metabolism of tolfenpyrad in soil-cultivated and hydroponic endive (Cichorium endivia) and the assessment of potential health risk

Tolfenpyrad is broadly used in the agricultural industry; however, the environmental fate of tolfenpyrad in crops has not been clearly demonstrated. In this work, the translocation and distribution of tolfenpyrad were investigated in endive under soil-cultivated and hydroponic conditions. Endive roots can easily absorb and accumulate tolfenpyrad from cultivation media due to the high bioconcentration factors (> > 1). Except for the easy downward translocation in hydroponic endive (translocation factors (TFs) close to 1), the upward and downward translocation was limited (TF < 1). Moreover, three metabolites were identified. Tolfenpyrad dissipated quickly in hydroponic endive (half-lives of 5.2–6.9 d) and the health risk is acceptable (risk quotient <100 %). These findings may be attributed to the hydrophobicity of tolfenpyrad, as well as specific morphological and growth rate properties of endive under different cultivation conditions. The results provide information for the proper application of tolfenpyrad and risk prevention in crops for consumers.