The rising concern over heavy metals (HMs) and microplastics (MPs) pollution in marine ecosystems, primarily driven by anthropogenic activities, poses significant threats to ecological health. Understanding the combined exposure of HMs and MPs aids in toxicity assessment. In this study, we examined the combined effects of polystyrene microplastics (MPs) and iron (Fe) on oxidative stress, bioaccumulation, histopathology, and genotoxicity in Namalycastis jaya. Oxidative stress was assessed by analyzing the levels of Superoxide dismutase (SOD), Catalase (CAT), Peroxidase (POD), Malondialdehyde (MDA), and Bicinchoninic acid (BCA), while genotoxicity was evaluated using the comet assay. Bioaccumulation analysis, conducted via Inductively coupled plasma-optical emission spectrometry (ICP-OES), indicated that the highest values (4.790 µg/ml) were observed in combined exposure, emphasizing the significant increase in iron (Fe) accumulation in polychaetes facilitated by MPs. Biochemical analysis revealed that oxidative damage in polychaetes became evident within 48 h of exposure to individual contaminants. However, in the case of combined exposures, elevated stress levels were observed within just 24 h. The genotoxic assay further demonstrated a higher degree of DNA damage in the combined exposure compared to individual exposures. Similarly, histopathology revealed mild alterations in the gut epithelium in combined exposures. It is evident that MPs intensify both oxidative and DNA damage induced by Fe in polychaetes. The insights gained from this study provide valuable information for the risk assessment of Fe and MPs in environmental safety, contributing to our understanding of the complex interactions between these pollutants in marine ecosystems.

中文翻译：

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评估铁 （Fe） 和微塑料的综合急性毒性对 Namalycastis jaya 的影响


主要由人为活动驱动的海洋生态系统中的重金属 （HMs） 和微塑料 （MP） 污染日益受到关注，这对生态健康构成了重大威胁。了解 HMs 和 MPs 的联合暴露有助于毒性评估。在这项研究中，我们检查了聚苯乙烯微塑料 （MPS） 和铁 （Fe） 对 Namalycastis jaya 氧化应激、生物积累、组织病理学和遗传毒性的综合影响。通过分析超氧化物歧化酶 （SOD） 、过氧化氢酶 （CAT）、过氧化物酶 （POD） 、丙二醛 （MDA） 和二辛可宁酸 （BCA） 水平来评估氧化应激，而使用彗星测定法评估遗传毒性。通过电感耦合等离子体发射光谱法 （ICP-OES） 进行的生物累积分析表明，在联合暴露中观察到最高值 （4.790 μg/ml），强调 MP 促进了多毛类中铁 （Fe） 积累的显着增加。生化分析显示，多毛类的氧化损伤在暴露于单个污染物后 48 小时内变得明显。然而，在联合暴露的情况下，在短短 24 小时内观察到压力水平升高。遗传毒性测定进一步表明，与个体暴露相比，联合暴露的 DNA 损伤程度更高。同样，组织病理学显示联合暴露中肠道上皮的轻度改变。很明显，MP 加剧了多毛类中 Fe 诱导的氧化损伤和 DNA 损伤。从这项研究中获得的见解为环境安全中 Fe 和 MP 的风险评估提供了有价值的信息，有助于我们理解海洋生态系统中这些污染物之间的复杂相互作用。