全氟辛烷磺酸对大型蚤的慢性毒性研究

采用大型蚤21天暴露和子代21天恢复实验法,研究了PFOS对大型蚤的慢性毒性效应及其子代F1(1st)和F1(3rd)的恢复情况。结果显示:PFOS质量浓度高于20mg/L时,F0代总产卵量、终点体长和内禀增长率都受到显著抑制。3个指标在最高浓度组与空白组相比,依次降低了62.2%,40.6%,34.0%(p<0.01)。随PFOS暴露浓度增加,其对大型蚤毒性逐渐加重,PFOS暴露浓度与对大型蚤毒性之间具有明显的剂量-效应关系。当PFOS质量浓度高于30mg/L时,F1(lst)代总产卵量和终点体长受到显著抑制。F1(3rd)代比F1(1st)代大型蚤恢复程度更好,除暴露于50mg/L的总产卵量、终点体长和内禀增长率仍受显著抑制,其他指标都恢复到接近空白组水平。大型蚤总产卵量、终点体长和内禀增长率作为最敏感的指标,建议将其用于评价PFOS的慢性毒性。

Research on chronic toxicity of perfluorooctane sulfonate to Daphnia magna

Though an experiment of exposing Daphnia magna and recovering its offspring for both 21 days, the chronic toxicity of perfluorooctane sulfonate (PFOS) to Daphnia magna and its first and third broods F₁ (1st) and F₁(3rd) were investigated. Results show that when the mass concentration of PFOS is higher than 20 mg/L, the number of offspring, length and innate increase rate are significantly inhibited. Compared with the control group, the reduction of the three indicators under the highest exposure concentration are 62.2%, 40.6%, 34.0%(p<0.01), respectively. The toxic effect becomes more serious with gradually increasing of exposure concentration, which shows an obvious dose-response relationship between PFOS concentration of exposure and the toxicity to Daphnia magna. The number of offspring and length of the F₁(1st) generation are significantly inhibited when PFOS mass concentration is higher than 30 mg/L. The F₁(3rd) generation''s recovery extent is better than that of the F₁(3rd) generation, and all the indicators recover closely to those of the control group except that the number of offspring, length and innate rate of increase are significantly inhibited when the Daphnia magna is exposed to the PFOS of 50 mg/L. As the most sensitive indicator, the number of offspring, length and innate rate of increase of Daphnia magna are suggested for evaluation of PFOS chronic toxicity.