Ding Jing, Liu Chenxu, Chen Qifang, Zhang Zhaoyun, Han Jinglong, Liang Aiping, Zhu Dong, Wang Hongtao, Lv Min, Chen Lingxin
School of Environmental and Material Engineering, Yantai University, 30 Qingquan Road, Yantai, 264005, China.
State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
Environ Pollut. 2022 Feb 1;294:118647. doi: 10.1016/j.envpol.2021.118647. Epub 2021 Dec 7.
Microplastics (MPs) have become an emerging threat for organisms. However, the toxicity mechanisms on biota, especially soil biota remain largely unclear. This study distinguished the effects of five types of MPs and their extractable additives on a typical soil oligochaete Enchytraeus crypticus using a traditional ecotoxicological approach combined with gut microbiota analysis. A variety of inorganic and organic compounds were screened in extractable solutions. Both MPs and their extractable additives decreased the growth and survival rates of the worms and shifted the gut microbiota, and the effects were type-specific. The differences between the effects of MPs and their extractable additives on traditional ecotoxicological parameters were insignificant, suggesting that extractable additives were the main toxicity pathways on soil fauna. The type-specific effects of MPs were attributed to the varied chemical compositions of extractable additives, and the compounds responsible for the shift of gut microbiota were further identified. The distinguishable effects on gut microbiota between MPs and their extractable additives together with the significant regressions between gut microbiota and traditional ecotoxicological parameters confirmed that gut microbiota could be a more sensitive indicator of organism's health conditions. Combined, the study provided an important insight into the toxicity mechanisms of MPs on soil fauna and extractable additives of MPs may be a hidden threat.
微塑料（MPs）已成为对生物体的一种新威胁。然而，其对生物群，尤其是土壤生物群的毒性机制仍 largely unclear。本研究采用传统生态毒理学方法结合肠道微生物群分析，区分了五种类型的微塑料及其可提取添加剂对典型土壤寡毛纲动物隐尾蚓的影响。在可提取溶液中筛选了多种无机和有机化合物。微塑料及其可提取添加剂均降低了蚯蚓的生长和存活率，并改变了肠道微生物群，且这些影响具有类型特异性。微塑料及其可提取添加剂对传统生态毒理学参数的影响差异不显著，这表明可提取添加剂是对土壤动物的主要毒性途径。微塑料的类型特异性影响归因于可提取添加剂的化学成分不同，并进一步确定了导致肠道微生物群变化的化合物。微塑料及其可提取添加剂对肠道微生物群的可区分影响以及肠道微生物群与传统生态毒理学参数之间的显著回归证实，肠道微生物群可能是生物体健康状况更敏感的指标。综合来看，该研究为微塑料对土壤动物的毒性机制提供了重要见解，微塑料的可提取添加剂可能是一个潜在威胁。
