Lately, the role of microplastics (MP) as vectors for dissolved contaminants and as vehicle for their transfer to aquatic organisms has received attention. Similarly to MP, other inorganic and organic particles may act as passive samplers. However, limited comparative knowledge exists at this respect. In the present study we have comparatively investigated the risk for mussel of MP and the pesticide chlorpyrifos (CPF) alone and in combination with MP and phytoplankton particles of microalgae (MP-CPF and MA-CPF, respectively). We selected MP and microalgae of similar size to expose mussel to the same volume of particles (≈1.5 mm ≈ equivalent to 1.5 mg MP ) and the same concentration of contaminant (CPF, 7.6 μg L). MP were virgin HDPE microparticles (≤10 μm) while the microalgae species was (4–8 μm). Mussels were exposed for 21 days to MP, CPF, MP-CPF and MA-CPF. Then, a suite of neurotoxicity, oxidative stress and oxidative damage biomarkers were measured in samples collected at day 7 and 21. Additionally, these biochemical markers were assessed in an integrated manner with others measured at physiological, immune and cell component level in the same organisms, previously published. Overall, MP did not elicit significant alterations on the majority of parameters measured. In contrast, mussels exposed to CPF, MA-CPF and MP-CPF showed evidence of neurotoxicity and oxidant imbalance at day 7, added to a detrimental physiological condition and immune imbalance at day 21. At the latter time MP-CPF mussels showed greater alterations than CPF or MA-CPF mussels. This suggested a synergistic toxicity of MP combined with CPF greater than that produced by the contaminants alone (MP or CPF) or by MA combined with CPF.

中文翻译：

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颗粒效应：毒死蜱与微塑料和浮游植物颗粒组合对贻贝的毒性比较


最近，微塑料（MP）作为溶解污染物的载体以及作为污染物转移到水生生物的载体的作用受到了人们的关注。与 MP 类似，其他无机和有机颗粒也可以充当被动采样器。然而，这方面的比较知识有限。在本研究中，我们比较研究了单独使用 MP 和农药毒死蜱 (CPF) 以及与 MP 和微藻浮游植物颗粒（分别为 MP-CPF 和 MA-CPF）组合对贻贝的风险。我们选择了相似大小的 MP 和微藻，将贻贝暴露于相同体积的颗粒（≈1.5 mm ≈ 相当于 1.5 mg MP）和相同浓度的污染物（CPF，7.6 μg·L）。 MP 是原始 HDPE 微粒（≤10 μm），而微藻物种是（4-8 μm）。贻贝暴露于 MP、CPF、MP-CPF 和 MA-CPF 中 21 天。然后，在第 7 天和第 21 天收集的样本中测量了一系列神经毒性、氧化应激和氧化损伤生物标志物。此外，这些生化标志物与同一生物体中在生理、免疫和细胞成分水平上测量的其他生物标志物以综合方式进行评估，先前发布。总体而言，MP 并未引起大多数测量参数的显着变化。相比之下，暴露于 CPF、MA-CPF 和 MP-CPF 的贻贝在第 7 天时表现出神经毒性和氧化不平衡的证据，并在第 21 天时加剧了有害的生理状况和免疫失衡。在后期，MP-CPF 贻贝显示出更大的变化比 CPF 或 MA-CPF 贻贝。这表明 MP 与 CPF 组合的协同毒性大于污染物单独（MP 或 CPF）或 MA 与 CPF 组合产生的协同毒性。