Wan Jun-Kit, Chu Wan-Loy, Kok Yih-Yih, Lee Choy-Sin
School of Postgraduate Studies, International Medical University, 126 Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Kuala Lumpur, Malaysia.
Division of Applied Biomedical Sciences and Biotechnology, School of Health Sciences, International Medical University, 126 Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Kuala Lumpur, Malaysia.
Environ Sci Pollut Res Int. 2021 Mar 1. doi: 10.1007/s11356-021-12983-x.
There has been increasing concern over the toxic effects of microplastics (MP), nanoplastics (NP), and copper (Cu) on microalgae. However, the combined toxicity of the metal in the presence of polystyrene (PS) MP/NP on microalgae has not been well studied, particularly after long-term exposure (i.e., longer than 4 days). The primary aim of the present study was to investigate the effect of PS MP and NP on Cu toxicity on two freshwater microalgae, namely Chlorella sp. TJ6-5 and Pseudokirchneriella subcapitata NIES-35 after acute exposure for 4 days and up to 16 days. The results showed that both microalgae were sensitive to Cu, but tolerant to MP/NP. However, MP/NP increased the toxicity of Cu at EC in both microalgae, which was only noticeable in chronic exposure. Single and combined treatment of MP/NP and Cu induced higher oxidative stress and caused morphological and ultrastructural changes in both microalgae. The adsorption of Cu to MP and NP was low (0.23-14.9%), with most of the Cu present in free ionic form (81.6-105.8%). The findings on different sensitivity of microalgae to Cu in the presence of MP/NP may have significant implication as microalgae are likely to be exposed to a mixture of both MP/NP and Cu in the environment. For example, in air-blasting technology, MP and NP are used as abrasive medium to remove Cu-containing antifouling paints on hulls of ship and submerged surfaces. Wastewater treatment plants receive household wastes containing MP and NP, as well as stormwater runoffs and industrial wastes contaminated with heavy metals.
微塑料（MP）、纳米塑料（NP）和铜（Cu）对微藻的毒性影响日益受到关注。然而，聚苯乙烯（PS）MP/NP存在时金属对微藻的联合毒性尚未得到充分研究，尤其是在长期暴露（即超过4天）之后。本研究的主要目的是在急性暴露4天至16天的情况下，研究PS MP和NP对两种淡水微藻（即小球藻TJ6-5和斜生栅藻NIES-35）Cu毒性的影响。结果表明，两种微藻对Cu敏感，但对MP/NP耐受。然而，MP/NP在两种微藻的半数效应浓度（EC）下增加了Cu的毒性，这仅在慢性暴露中明显。MP/NP和Cu的单一及联合处理在两种微藻中均诱导了更高的氧化应激，并导致形态和超微结构变化。Cu在MP和NP上的吸附率较低（0.23 - 14.9%），大部分Cu以游离离子形式存在（81.6 - 105.8%）。微藻在MP/NP存在下对Cu的不同敏感性的研究结果可能具有重要意义，因为微藻在环境中可能会接触到MP/NP和Cu的混合物。例如，在鼓风技术中，MP和NP被用作研磨介质以去除船舶船体和水下表面含Cu的防污漆。污水处理厂接收含有MP和NP的家庭废物，以及受重金属污染的雨水径流和工业废物。
