Liu Yanwei, Huang Weigang, Wang Yujue, Wen Qian, Zhou Juanjuan, Wu Shengze, Liu Hui, Chen Guikui, Qiu Rongliang
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
Guangdong Testing Institute of Product Quality Supervision, Foshan 528300, China.
Sci Total Environ. 2024 Mar 1;914:169964. doi: 10.1016/j.scitotenv.2024.169964. Epub 2024 Jan 10.
Naturally aged microplastics (NAMPs) and arsenic (As) have been reported to coexist in and threaten potentially to soil-plant ecosystem. The research explored the combined toxic effects of NAMPs and As to lettuce (Lactuca sativa L.) growth, and the distribution, accumulation and bioavailability of As in soil aggregates. The As contaminated soil with low, medium and high concentrations (L-As, M-As, H-As) were treated with or without NAMPs, and a total of six treatments. The results displayed that, in comparison to separate treatments of L-As and M-As, the presence of NAMPs increased the total biomass of lettuce grown at these two As concentrations by 68.9 % and 55.4 %, respectively. Simultaneous exposure of NAMPs and L-As or M-As led to a decrease in As content in shoot (0.45-2.17 mg kg) and root (5.68-14.66 mg kg) of lettuce, indicating an antagonistic effect between them. In contrast, co-exposure to H-As and NAMPs showed synergistic toxicity, and the leaf chlorophyll and nutritional quality of lettuce were also reduced. NAMPs altered the ratio of different soil aggregate fractions and the distribution of bioavailable As within them, which influenced the absorption of As by lettuce. In conclusion, these direct observations assist us in enhancing the comprehend of the As migration and enrichment characteristics in soil-plant system under the influence of NAMPs.
据报道，自然老化微塑料（NAMPs）和砷（As）在土壤-植物生态系统中共同存在并可能构成威胁。本研究探讨了NAMPs和As对生菜（Lactuca sativa L.）生长的联合毒性效应，以及As在土壤团聚体中的分布、积累和生物有效性。将低、中、高浓度（L-As、M-As、H-As）的As污染土壤分别进行有无NAMPs处理，共六种处理。结果表明，与单独的L-As和M-As处理相比，NAMPs的存在使这两种As浓度下生长的生菜总生物量分别增加了68.9%和55.4%。NAMPs与L-As或M-As同时暴露导致生菜地上部（0.45 - 2.17 mg kg）和根部（5.68 - 14.66 mg kg）的As含量降低，表明它们之间存在拮抗作用。相反，H-As与NAMPs共同暴露表现出协同毒性，生菜的叶片叶绿素和营养品质也降低。NAMPs改变了不同土壤团聚体组分的比例以及其中生物可利用As的分布，进而影响了生菜对As的吸收。总之，这些直接观察结果有助于我们加深对NAMPs影响下土壤-植物系统中As迁移和富集特征的理解。
