Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia.
Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia.
Environ Pollut. 2021 Jun 1;278:116910. doi: 10.1016/j.envpol.2021.116910. Epub 2021 Mar 10.
Plastic particles smaller than 1 μm are considered to be highly dangerous pollutants due to their ability to penetrate living cells. Model experiments on the toxicity of plastics should be correlated with actual concentrations of plastics in natural water. We simulated the natural destruction of polystyrene, polyvinyl chloride, and poly(methyl methacrylate) in experiments on the abrasion of plastics with small stones. The plastics were dyed in mass with a fluorescent dye, which made it possible to distinguish plastic particles from stone fragments. We found that less than 1% of polystyrene and polyvinyl chloride were converted to submicron size particles. In the case of more rigid poly(methyl methacrylate), the fraction of such particles reaches 11%. The concentration of particles with a diameter less than 1 μm in the model experiments was from 0.7 (polystyrene) to 13 mg/L (poly(methyl methacrylate)), and when transferring the obtained data to real reservoirs, these values should be reduced by several orders of magnitude. These data explain the difficulties associated with the search for nanoplastics in natural waters. The toxicity of such particles to hydrobionts in model experiments was detected for concentrations greater than 1 mg/L, which is unrealistic in nature. Detectable and toxic amounts of nano- and submicron plastic particles in living organisms can be expected only in the case of filter-feeding organisms, such as molluscs, krill, sponges, etc.
小于 1μm 的塑料颗粒被认为是高度危险的污染物，因为它们能够穿透活细胞。塑料毒性的模型实验应与天然水中塑料的实际浓度相关联。我们通过用小石子磨损塑料的实验模拟了聚苯乙烯、聚氯乙烯和聚甲基丙烯酸甲酯在自然环境中的破坏。这些塑料被大量染色，使用荧光染料可以将塑料颗粒与石头碎片区分开来。我们发现，不到 1%的聚苯乙烯和聚氯乙烯转化为亚微米大小的颗粒。对于更硬的聚甲基丙烯酸甲酯，这种颗粒的比例达到 11%。在模型实验中，直径小于 1μm 的颗粒浓度从 0.7（聚苯乙烯）到 13mg/L（聚甲基丙烯酸甲酯）不等，在将获得的数据转换到实际储层时，这些值应降低几个数量级。这些数据解释了在天然水中寻找纳米塑料所面临的困难。在模型实验中，只有当浓度大于 1mg/L 时，才能检测到这些颗粒对水生生物的毒性，而在自然界中，这种浓度是不现实的。只有在滤食性生物（如软体动物、磷虾、海绵等）中，才能预期到生物体中存在可检测到的有毒量的纳米和亚微米塑料颗粒。
