Centre for Environmental Sustainability and Remediation, School of Science, RMIT University, Bundoora, Victoria 3083, Australia.
Centre for Environmental Sustainability and Remediation, School of Science, RMIT University, Bundoora, Victoria 3083, Australia.
Sci Total Environ. 2020 Sep 10;734:138559. doi: 10.1016/j.scitotenv.2020.138559. Epub 2020 May 14.
Microplastic ingestion in invertebrates reduces somatic and reproductive growth. This could be caused by energy reserves being detracted from growth processes and redistributed to maintenance processes that preserve life. A potential sink for this diverted energy is the antioxidant system, which minimises oxidative damage and reinstates redox homeostasis following disturbances caused by exposure to pollution. Several microplastic studies have used genetic and molecular redox biomarkers to assess how microplastic ingestion affects the functioning of the antioxidant system. This systematic review synthesises the current understanding of redox biomarker responses in invertebrates that have ingested microplastics. We found that biomarker response information exists for only seven invertebrate taxa, and early life stages have received little scientific attention. The microplastics used by most studies were polystyrene (45% of studies), spherical (51% of studies), and were < 10 μm in diameter (31% of studies). We found multiple examples of microplastic ingestion posing an oxidative challenge to invertebrates, which required upregulation of antioxidant system components. However, the lack of systematic experiments prevented us from clearly identifying which characteristic of microplastics caused these responses. We identify several areas for consideration when investigating biomarker responses to microplastic ingestion and offer research priorities for future studies.
无脊椎动物摄入微塑料会减少其体躯和生殖生长。这可能是由于能量储备被转移到维持生命的过程中，从而影响了生长过程。这种被转移的能量可能会被抗氧化系统消耗，该系统可以减少氧化损伤，并在因暴露于污染而引起的干扰后恢复氧化还原平衡。一些微塑料研究已经使用遗传和分子氧化还原生物标志物来评估摄入微塑料如何影响抗氧化系统的功能。本系统综述综合了目前对摄入微塑料的无脊椎动物的氧化还原生物标志物反应的理解。我们发现，只有七种无脊椎动物类群的生物标志物反应信息，而很少有科学研究关注早期生命阶段。大多数研究中使用的微塑料是聚苯乙烯（45%的研究）、球形（51%的研究），且直径小于 10μm（31%的研究）。我们发现多个微塑料摄入对无脊椎动物造成氧化应激的例子，这需要上调抗氧化系统成分。然而，由于缺乏系统的实验，我们无法清楚地确定是微塑料的哪些特征导致了这些反应。我们确定了在研究微塑料摄入对生物标志物反应时需要考虑的几个方面，并为未来的研究提供了研究重点。
