Breitholtz Magnus, Wollenberger Leah, Dinan Laurence
Institute of Applied Environmental Research (ITM), Stockholm University, S-10691, Stockholm, Sweden.
Aquat Toxicol. 2003 Apr 10;63(2):103-18. doi: 10.1016/s0166-445x(02)00159-5.
A full life-cycle (</=26 days exposure) toxicity test with the harpacticoid copepod Nitocra spinipes was used to study the effects of one nitro musk (musk ketone) as well as three polycyclic musks (Tonalide, Celestolide and Galaxolide). A subchronic individual life-table endpoint, the larval development rate, was recorded after 7-8 days exposure of juveniles and was significantly decreased in copepods exposed to sublethal concentrations of musk ketone, Celestolide and Galaxolide. However, none of the Tonalide concentrations had any effect on larval development. The lowest Galaxolide concentration (0.02 mg/l), which affected juvenile development, was about 100 times below the adult 96-h-LC(50)-value of 1.9 mg/l (95% confidence interval: 1.4-2.7 mg/l). However, none of the four musks had any agonistic or antagonistic activity in the ecdysteroid-sensitive Drosophila melanogaster B(II)-cell line. This indicates that the decrease in larval development rate was due to pharmacological effects rather than steroid receptor-mediated endocrine disruption. A modified Euler-Lotka equation was used to calculate a population-level endpoint, the intrinsic rate of natural increase (r(m)), from individual life-table endpoints, i.e. mortality rate, time of release of first brood, sex ratio, the fraction of ovigerous females among all females as well as the number of nauplii per ovigerous female. The second highest musk ketone concentration (0.1 mg/l) was the only treatment, which significantly affected r(m) (***P<0.001). At the highest musk ketone (0.3 mg/l) and Celestolide (0.3 mg/l) concentrations, all copepods were dead at the end of the exposures. This shows that a sensitive individual life-table endpoint is protective over the population-level endpoint r(m). Though we think that it is necessary to obtain population-level endpoints from standardised toxicity test, for ecologically successful risk characterisation of synthetic musks as well as other chemicals. The results from the present study show that it is possible to obtain population-level data from the full life-cycle test with N. spinipes. However, there seems to be little risk that synthetic musks are harmful to copepods at present environmental concentrations.
利用猛水蚤类桡足动物尖额刺镖水蚤进行了全生命周期（暴露时间≤26天）毒性试验，以研究一种硝基麝香（酮麝香）以及三种多环麝香（吐纳麝香、佳乐麝香和 galaxolide）的影响。在幼体暴露7 - 8天后，记录了一个亚慢性个体生命表终点指标，即幼体发育速率，暴露于亚致死浓度的酮麝香、佳乐麝香和galaxolide的桡足动物的幼体发育速率显著降低。然而，吐纳麝香的所有浓度对幼体发育均无影响。影响幼体发育的最低galaxolide浓度（0.02 mg/l）比成年个体96小时半数致死浓度（LC(50)）值1.9 mg/l（95%置信区间：1.4 - 2.7 mg/l）低约100倍。然而，这四种麝香在蜕皮甾类敏感的黑腹果蝇B(II)细胞系中均无激动或拮抗活性。这表明幼体发育速率的降低是由于药理作用而非类固醇受体介导的内分泌干扰。使用修正的欧拉 - 洛特卡方程，根据个体生命表终点指标，即死亡率、首次产卵时间、性别比、所有雌性中抱卵雌体的比例以及每个抱卵雌体的无节幼体数量，计算出一个种群水平的终点指标，即自然内禀增长率（r(m)）。第二高的酮麝香浓度（0.1 mg/l）是唯一显著影响r(m)的处理（***P<0.001）。在最高的酮麝香（0.3 mg/l）和佳乐麝香（0.3 mg/l）浓度下，所有桡足动物在暴露结束时均死亡。这表明一个敏感的个体生命表终点指标对种群水平的终点指标r(m)具有保护作用。尽管我们认为有必要从标准化毒性试验中获取种群水平的终点指标，以便对合成麝香以及其他化学品进行生态上成功的风险特征描述。本研究结果表明，有可能从尖额刺镖水蚤的全生命周期试验中获取种群水平的数据。然而，目前环境浓度下合成麝香对桡足动物有害的风险似乎很小。
