塑料在许多方面使我们的生活受益,但是它们在环境中的长期坚持会导致严重的问题。塑料在使用后的快速分解和解毒是重大挑战。作为一种可能的解决方案,生物降解塑料引起了人们的注意,以及聚合物毒性的环境风险评估研究,使用指示生物,像水蚤和鱼,在全球范围内增加。然而,此类研究通常集中在标准化物质上,而不考虑由于塑料降解产品而引起的毒性变化。此外,测试通常集中在急性毒性,而对生物体繁殖和寿命的长期影响在很大程度上是未知的。了解降解聚合物对生物活性的影响对于准确的风险评估至关重要。在这项研究中,我们研究了聚己内酯(PCL)降解过程中产生的物质的生物毒性,一种常见的可生物降解的塑料,使用指示生物,大型水蚤.我们检查了PCL,低聚己内酯(OCL),和聚合物裂解产生的单体,以及碳二亚胺,在聚酯合成过程中添加。因此,PCL,不溶于水,在100mg/L的暴露浓度下降低个体存活率和后代总数,虽然水溶性降解产物没有观察到毒性,OCL,和单体。此外,碳化二亚胺,预计在PCL降解过程中会释放,表现出强烈的毒性,0.1-10mg/L显着降低个体存活率和后代总数。这些发现表明,由于聚合物降解和添加剂释放而引起的物理性质变化可以显着改变其毒性。
Plastics have benefited our lives in many ways, but their long persistence in the environment causes serious problems. Rapid decomposition and detoxification of plastics after use are significant challenges. As a possible solution, biodegradable plastics have attracted attention, and for environmental risk assessment research on polymer toxicity, use of indicator organisms, like water fleas and fish, has increased globally. However, such research often focuses on standardized substances without considering changes in toxicity due to plastic degradation products. Additionally, tests generally focus on acute toxicity, while long-term effects on organismal reproduction and lifespan are largely unknown. Understanding the impact of degraded polymers on biological activities is crucial for accurate risk assessment. In this study, we investigated the biological toxicity of substances generated during degradation of polycaprolactone (PCL), a common biodegradable plastic, using the indicator organism, Daphnia magna. We examined PCL, oligocaprolactones (OCLs), and monomers resulting from polymer cleavage, as well as carbodiimides, added during polyester synthesis. As a result, PCL, which is insoluble in water, reduced individual survival and total number of offspring at an exposure concentration of 100 mg/L, while no toxicity was observed for water-soluble degradation products, OCLs, and monomers. Furthermore, carbodiimides, which are expected to be released during PCL degradation, showed strong toxicity, significantly reducing individual survival and total number of offspring at 0.1-10 mg/L. These findings suggest that changes in physical properties due to polymer degradation and release of additives can significantly alter their toxicity.