水环境中的微塑料：环境危害的本证和反证及主要研究空白

科学界与公众对微塑料(microplastics, MPs)的污染越来越重视。我们对文献进行了系统综述，以评价MPs对环境危害的证据权重。我们发现MPs在地表水和沉积物中均有存在。主要以珠状组成为主的碎片和纤维只是检测到的MP形态中的一小部分。检测出的MPs环境浓度很低，与能够影响生物分子水平上的毒性终点、以及摄食、繁殖、生长、组织炎症和死亡率的浓度有数量级的差别。MPs作为疏水性有机化合物的携带者使其在生物体中富集的作用很弱。现有数据表明MPs对环境造成的危害并不明显。实验室毒性实验中使用的MPs与环境中检测到的MPs在颗粒形态、尺寸范围和浓度等方面都有差距。研究中环境介质的选择少受关注。我们亟需开展更高质量的整体监测和更多实际环境效应的研究。只有这样，我们才能够全面表征MPs的环境风险，以便制定实施真正改善环境质量的管控措施。 精选自Emily E. Burns, Alistair B.A. Boxall. Microplastics in the aquatic environment: Evidence for or against adverse impacts and major knowledge gaps. Environmental Toxicology and Chemistry,2018,37:2776–2796.
详情请见 https://doi.org/10.1002/etc.4268

Microplastics in the aquatic environment: Evidence for or against adverse impacts and major knowledge gaps

There is increasing scientific and public concern over the presence of microplastics (MPs) in the natural environment. Here, we present the results of a systematic review of the literature to assess the weight of evidence for MPs causing environmental harm. We conclude that MPs do occur in surface water and sediments. Fragments and fibers predominate with beads making up only a small proportion of the detected MP types. Concentrations detected are orders of magnitude lower than those reported to affect molecular level endpoints, feeding, reproduction, growth, tissue inflammation and mortality in organisms. The evidence for MPs acting as a vector for hydrophobic organic compounds (HOC) to accumulate in organisms is also weak. The available data therefore suggest that these materials are not causing harm to the environment. There is however a mismatch between the particle types, size ranges, and concentrations of MPs used in laboratory tests and those measured in the environment. Select environmental compartments have also received limited attention. There is an urgent need for studies that address this mismatch by performing better quality and more holistic monitoring studies alongside more environmentally realistic effects studies. Only then will we be able to fully characterize risks of MPs to the environment in order to support the introduction of regulatory controls that can make a real positive difference to environmental quality.