Humans are exposed to plastic particles, but there are no studies on environmental plastics in cell cultures or animals. The toxicological understanding arises from model particles like polystyrene, polyethylene or non-plastic particles like food-grade titanium dioxide. The majority of studies on polystyrene particles show toxicological effects on measures of oxidative stress, inflammation, mitochondrial dysfunction, lysosomal dysfunction and apoptosis. The toxic effects in cell cultures mainly occur at high concentrations. Polyethylene particles seem to generate inflammatory reactions, whereas other toxicological effects have not been assessed. There are very few studies on effects of polystyrene particles in animal models and these have not demonstrated overt indices of toxicity. Studies in animals are the likely way for hazard assessment of micro- or nanoplastics. However, co-culture systems that mimic the complex architecture of mammalian tissues can cost-efficiently determine the hazards of micro- and nanoplastics. Future studies should include low doses of micro- and nanoplastic particles, which are more relevant in the assessment of health risk than the extrapolation of effects from high doses to realistic doses. Based on studies on model particles, environmental exposure to micro- and nanoplastic particles may be a hazard to human health.

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小尺寸塑料颗粒的危害评估：颗粒毒理学的概念框架有用吗？

人类会接触到塑料颗粒，但是尚无关于细胞培养物或动物中环境塑料的研究。毒理学理解来自模型颗粒，例如聚苯乙烯，聚乙烯或非塑料颗粒，例如食品级二氧化钛。对聚苯乙烯颗粒的大多数研究表明，其对氧化应激，炎症，线粒体功能障碍，溶酶体功能障碍和细胞凋亡的测定具有毒理学作用。细胞培养物中的毒性作用主要发生在高浓度下。聚乙烯颗粒似乎会产生炎症反应，而其他毒理作用尚未评估。很少有关于聚苯乙烯颗粒在动物模型中作用的研究，并且这些研究还没有显示出明显的毒性指数。动物研究是评估微塑料或纳米塑料危害的可能方法。但是，模仿哺乳动物组织复杂结构的共培养系统可以经济高效地确定微塑料和纳米塑料的危害。未来的研究应包括低剂量的微米级和纳米级塑料颗粒，与从高剂量到实际剂量的外推作用相比，与健康风险评估更相关。根据对模型颗粒的研究，环境中暴露于微米和纳米塑料颗粒可能会对人体健康造成危害。与从高剂量向实际剂量进行外推相比，与评估健康风险更相关。根据对模型颗粒的研究，环境中暴露于微米和纳米塑料颗粒可能会对人体健康造成危害。与从高剂量向实际剂量进行外推相比，与评估健康风险更相关。根据对模型颗粒的研究，环境中暴露于微米和纳米塑料颗粒可能会对人体健康造成危害。