Triadimefon, a chiral fungicide, could be metabolized to triadimenol which has two chiral centers. In this work, Tubifex tubifex was exposed to triadimefon through the aqueous and soil phase to explore the relative importance of the routes of uptake. Bioaccumulation of triadimefon in tubifex was detected in both treatments, and the kinetics of the accumulation processes were significantly different in these two experiments. In spiked water treatment, (S)-triadimefon was preferentially accumulated over the (R)-triadimefon, whereas the enantioselective bioaccumulation was not detected in the spiked soil microenvironment. Simultaneously, four stereoisomers of triadimenol were also found in the tubifex tissue. Although the amount of these stereoisomers were different from each other with relatively more accumulation of the most fungi-toxic stereoisomer (1S,2R), the abundance ratios in the two exposure treatments were similar at the same sampling, following the order (1S,2S) > (1R,2S) > (1R,2R) > (1S,2R). The bioaccumulation factor was calculated for parent compound triadimefon and metabolite enrichment factor for metabolite. The results showed that both uptake routes, epidermal contact in the aqueous phase and ingestion of solid particles in soil, were important to the bioaccumulation of the triadimefon and triadimenol in tubifex.

No abstract

No abstract

No abstract

No abstract

No abstract

No abstract

The enantioselective bioactivity, toxicity, and environmental behaviors of isocarbophos (ICP) were investigated. The order of the bioactivity and toxicity was S-(+) ≥ rac > R-(−), and the difference of R-(−) and S-(+) was up to 232 times. The usage of S-(+)-ICP may efficiently reduce the usage amount of rac-ICP by 35% under the same effect, and the toxicity was not increased. Based on the toxic unit analysis, the additive effect and synergistic effect of ICP enantiomers were found in the four nontarget organisms, and R-(−)-ICP might cooperate the side-effects of S-(+)-ICP. The accumulation of rac-ICP in earthworms was enantioselective with an enantioenrichment of R-(−)-ICP, so the usage of racemic ICP might increase the exposure risk of R-(−)-ICP to earthworms. From the comprehensive results, the production of enantiomer enriched S-(+)-ICP might increase bioactivity and reduce environmental pollution, while the toxicity of S-(+)-ICP to other nontarget organisms needs to be further assessed.