不同材质微塑料对三氯生的吸附及其在斑马鱼体内累积分布的影响

The Adsorption of Tricolsan by Microplastics of Different Polymers and Its Effect on Tricolsan Accumulation in Zebrafish

微塑料(MPs)通过吸附作用不仅可以影响有机污染物在环境中的迁移、转化和归趋,甚至会影响污染物在生物体内的累积分布和毒性效应。为考察MPs和三氯生(TCS)等在环境中复合污染的生态和健康风险,以斑马鱼为模式生物,以聚乙烯(PE)、聚丙烯(PP)和聚氯乙烯(PVC)材质MPs为目标MPs,TCS为目标污染物,开展了不同材质MPs对TCS的吸附和生物累积实验。吸附实验结果表明,3种MPs对TCS的吸附能力依次为:PP>PE≈PVC。MPs对TCS的吸附机制主要为表面吸附和外液膜扩散作用,吸附过程为多层吸附。累积分布实验结果表明,单独TCS暴露条件下,TCS在肠道、肝脏、脑、性腺和剩余鱼体中的累积量分别为191.56、63.92、21.32、25.19和11.59μg·g-1。MPs的存在显著提高了TCS在斑马鱼肠道和肝脏中的累积量,与TCS组相比,TCS+PP组、TCS+PE组和TCS+PVC组中肠道TCS的累积量分别提高了51.9%、12.7%和38.6%(P<0.05),肝脏TCS的累积量分别提高了152.9%、70.9%和118.4%(P<0.05)。此外,TCS累积量与MPs的吸附能力呈正相关,PP+TCS组肠道和肝脏中TCS累积量显著高于TCS+PE组和TCS+PVC组(P<0.05)。本文详细探究了不同材质MPs对TCS的吸附和生物累积的影响,研究结果可为MPs和有机污染物复合污染的生态和健康风险评价提供基础数据。

Microplastics(MPs)can not only affect the migration,transformation and fate of organic pollutants in the environment,but also affect the bioaccumulation,distribution and toxic effect of organic pollutants in the organism.Considering the environmental health risks of the coexistence of MPs and triclosan(TCS)in the environment,the adsorption and bioaccumulation experiments were conducted by using zebrafish as the model organism,MPs of the polymers of polyethylene(PE),polypropylene(PP)and polyvinyl chloride(PVC)as the target MPs,and TCS as the target pollutant.The results of adsorption experiments show that the adsorption capacity of three types of MPs for TCS follows the order of PP>PE≈PVC.The adsorption mechanism of MPs for TCS is mainly surface adsorption and gradual sorption by intra-particle diffusion.The adsorption process is multi-layer adsorption.For TCS alone exposure,the accumulation of TCS was 191.56,63.92,21.32,25.19,and 11.59μg·g-1 in the gut,liver,brain,gonad and rest body,respectively.MPs significantly increased the accumulation of TCS in the gut and liver.Compared with the TCS group,the accumulation of TCS in the gut of TCS+PP group,TCS+PE group and TCS+PVC group significantly increased by 51.9%,12.7%and 38.6%(P<0.05),and the accumulation of TCS in the liver of TCS+PP group,TCS+PE group and TCS+PVC group significantly increased by 152.9%,70.9%and 118.4%(P<0.05).In addition,the accumulation of TCS was positively correlated with the adsorption capacity of MPs.TCS accumulation in the gut and liver of TCS+PP group was higher than that of TCS+PE and TCS+PVC groups(P<0.05).The influence of MPs of different polymers on the bioaccumulation and distribution of TCS were studied and the results can provide basic data for the environmental health risk assessment of the combined effects of MPs and organic pollutants.