Lai Hailong, Han Shuwen, Sun Jinyu, Fang Yujing, Liu Ping, Zhao Haitao
College of Environmental Science and Engineering, Yangzhou University, 225009, Yangzhou, Jiangsu Province, China.
Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700AB, Wageningen, the Netherlands.
Heliyon. 2024 Aug 31;10(18):e37308. doi: 10.1016/j.heliyon.2024.e37308. eCollection 2024 Sep 30.
Many studies have reported the toxic effects of microplastics (MPs) on organisms, especially on how conventional plastics affect organisms after short-term exposure. The effects of biodegradable plastics on organisms are, however, largely unexplored, especially concerning their impact after long-term exposure. We perform a series of experiments to examine the effects of conventional (polyethylene (PE)) and biodegradable (polylactic acid (PLA)) microplastics on earthworms at three concentrations (0.5 %, 2 %, and 5 % (w/w)) and particle sizes (149, 28, and 13 μm) over short- (14 d) and long-term (28 d) periods of exposure. Negative effects on earthworms are more pronounced following exposure to PE than PLA, particularly over the shorter term. After longer-term exposure, earthworms may adapt to PE and PLA environments. A close relationship exists between the effects of MPs on earthworms and activities of superoxide dismutase, catalase, and malondialdehyde enzymes, which we use to evaluate the degree of antioxidant damage. We report both PE and PLA to negatively affect earthworms, but for the effects of PLA to be less severe after longer-term exposure. Further investigation is required to more fully assess the potential negative effects of PLA use on soil organisms in agriculture.
许多研究报告了微塑料（MPs）对生物体的毒性作用，特别是传统塑料在短期暴露后如何影响生物体。然而，可生物降解塑料对生物体的影响在很大程度上尚未得到探索，尤其是长期暴露后的影响。我们进行了一系列实验，以研究传统（聚乙烯（PE））和可生物降解（聚乳酸（PLA））微塑料在三种浓度（0.5%、2%和5%（w/w））和粒径（149、28和13μm）下，在短期（14天）和长期（28天）暴露期间对蚯蚓的影响。暴露于PE后对蚯蚓的负面影响比PLA更明显，特别是在短期内。长期暴露后，蚯蚓可能会适应PE和PLA环境。MPs对蚯蚓的影响与超氧化物歧化酶、过氧化氢酶和丙二醛酶的活性之间存在密切关系，我们用这些酶来评估抗氧化损伤的程度。我们报告PE和PLA都会对蚯蚓产生负面影响，但长期暴露后PLA的影响较轻。需要进一步调查，以更全面地评估PLA在农业中使用对土壤生物的潜在负面影响。
