Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS/UBO/IRD/IFREMER - Institut Universitaire Européen de la Mer, Technopôle Brest-Iroise - Rue Dumont d'Urville, 29280 Plouzané, France.
Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS/UBO/IRD/IFREMER - Institut Universitaire Européen de la Mer, Technopôle Brest-Iroise - Rue Dumont d'Urville, 29280 Plouzané, France; CEDRE, 715 rue Alain Colas, 29218 BREST Cedex 2, France.
Environ Pollut. 2016 Sep;216:724-737. doi: 10.1016/j.envpol.2016.06.039. Epub 2016 Jun 29.
The effects of polystyrene microbeads (micro-PS; mix of 2 and 6 μm; final concentration: 32 μg L(-1)) alone or in combination with fluoranthene (30 μg L(-1)) on marine mussels Mytilus spp. were investigated after 7 days of exposure and 7 days of depuration under controlled laboratory conditions. Overall, fluoranthene was mostly associated to algae Chaetoceros muelleri (partition coefficient Log Kp = 4.8) used as a food source for mussels during the experiment. When micro-PS were added in the system, a fraction of FLU transferred from the algae to the microbeads as suggested by the higher partition coefficient of micro-PS (Log Kp = 6.6), which confirmed a high affinity of fluoranthene for polystyrene microparticles. However, this did not lead to a modification of fluoranthene bioaccumulation in exposed individuals, suggesting that micro-PS had a minor role in transferring fluoranthene to mussels tissues in comparison with waterborne and foodborne exposures. After depuration, a higher fluoranthene concentration was detected in mussels exposed to micro-PS and fluoranthene, as compared to mussels exposed to fluoranthene alone. This may be related to direct effect of micro-PS on detoxification mechanisms, as suggested by a down regulation of a P-glycoprotein involved in pollutant excretion, but other factors such as an impairment of the filtration activity or presence of remaining beads in the gut cannot be excluded. Micro-PS alone led to an increase in hemocyte mortality and triggered substantial modulation of cellular oxidative balance: increase in reactive oxygen species production in hemocytes and enhancement of anti-oxidant and glutathione-related enzymes in mussel tissues. Highest histopathological damages and levels of anti-oxidant markers were observed in mussels exposed to micro-PS together with fluoranthene. Overall these results suggest that under the experimental conditions of our study micro-PS led to direct toxic effects at tissue, cellular and molecular levels, and modulated fluoranthene kinetics and toxicity in marine mussels.
聚苯乙烯微珠（微 PS；2 和 6 μm 的混合物；最终浓度：32 μg/L）单独或与荧蒽（30 μg/L）联合作用于海洋贻贝 Mytilus spp. 的影响，在控制实验室条件下暴露 7 天和净化 7 天后进行了研究。总体而言，荧蒽主要与作为贻贝实验期间食物来源的藻类 Chaetoceros muelleri 相关联（分配系数 Log Kp=4.8）。当系统中添加微 PS 时，FLU 的一部分从藻类转移到微珠上，这表明微 PS 的分配系数更高（Log Kp=6.6），这证实了荧蒽对聚苯乙烯微珠的高亲和力。然而，这并没有导致暴露个体中荧蒽的生物积累发生变化，这表明与水相和食物相暴露相比，微 PS 在将荧蒽转移到贻贝组织中的作用较小。净化后，暴露于微 PS 和荧蒽的贻贝中检测到的荧蒽浓度高于仅暴露于荧蒽的贻贝。这可能与微 PS 对解毒机制的直接影响有关，如参与污染物排泄的 P-糖蛋白下调所表明的那样，但不能排除其他因素，如过滤活性受损或肠道中仍存在珠粒。微 PS 本身导致血细胞死亡率增加，并引发细胞氧化平衡的实质性调节：血细胞中活性氧的产生增加，以及贻贝组织中抗氧化和谷胱甘肽相关酶的增强。在同时暴露于微 PS 和荧蒽的贻贝中观察到最高的组织病理学损伤和抗氧化标志物水平。总的来说，这些结果表明，在我们研究的实验条件下，微 PS 导致了组织、细胞和分子水平的直接毒性作用，并调节了海洋贻贝中荧蒽的动力学和毒性。
