This paper is relevant to the impact areas in the following areas:
|Insect Res. (BT), Insect Resistance
|aquatic nontarget organisms
Abstract or Summary
The widespread cultivation of Bacillus thuringiensis crops has raised public concerns on their risk to nontarget organisms. Persistence of Cry1Ac protein in soil, sediment and water and its toxicity to nontarget aquatic organisms were determined. The dissipation of Cry1Ac toxin was well described using first order kinetics, with the half-lives (DT50) ranging from 0.8 to 3.2, 2.1 to 7.6 and 11.0 to 15.8 d in soil, sediment and water, respectively. Microbial degradation played a key role in the dissipation of Cry1Ac toxin and high temperature accelerated the processes. Cry1Ac toxin was more toxic to the midge Chironomus dilutusthan the amphipod Hyalella azteca, with the median lethal concentration (LC50) of C. dilutusbeing 155 ng/g dry weight and 201 ng/mL in 10-d sediment and 4-d water bioassays, respectively. While Cry1Ac toxin showed toxicity to the midges, risk of Bt proteins to aquatic nontarget organisms was limited because their environmentally relevant concentrations were much lower than the LC50s.
Dissipation of Insecticidal Cry1Ac Protein and Its Toxicity to Nontarget Aquatic Organisms (held on an external server, and so may require additional authentication details)
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