Fate of 14C-bisphenol F isomers in an oxic soil and the effects of earthworm

Abstract

Bisphenol F (BPF) pollution in environment increased, but the studies on its fate and uptake in soil-earthworm systems were limited. Using 14C-tracers, environmental fate of BPF isomers in an oxic rice soil with/without earthworm Metaphire guillelmi was studied. After 59 days of incubation, mineralization increased in the order of 2,2′-BPF (18.7% ± 0.3% of the initial amount) < 2,4′-BPF (21.7% ± 0.2%) < 4,4′-BPF (26.9% ± 0.1%). About 70% was converted to bound residues (BRs) and most of the BRs resided in the humin fraction by physical entrapment and ester-linkages. M. guillelmi decreased the mineralization and BRs of 4,4′-BPF in soil, indicating that earthworm increased the ecological risk of 4,4′-BPF. About 5.2% ± 0.1% of the initial amount was accumulated in M. guillelmi and mostly in gut. Considerable amounts of the accumulated 4,4′-BPF were present as earthworm-bound residues (earthworm-BRs). The elimination of 4,4′-BPF from M. guillelmi was very slow, and there was still 96.2% of the initial accumulated radioactivity presented in earthworm after 5 days of depuration. The results of this study firstly provide the isomer - specific partitioning of three BPF isomers in an oxic soil and the uptake and depuration of 4,4′-BPF in earthworm during soil incubation.