College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China.
College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China; College of Environment and Resources, Southwest University of Science & Technology, Mianyang, 621010, China.
Environ Pollut. 2024 May 1;348:123787. doi: 10.1016/j.envpol.2024.123787. Epub 2024 Mar 26.
The co-occurrence of microplastics (MPs) and heavy metal(loid)s (HMs) has attracted growing scientific interest because of their wide distribution and environmental toxicity. Nevertheless, the interactions between MPs and HMs in soil-plant systems remain unclear. We conducted a meta-analysis with 3226 observations from 87 independent studies to quantify the impact of MPs addition on the plant biomass and HMS accumulation. Co-occurrence of MPs and HMs (except for As) induced synergistic toxicity to plant growth. MPs promoted their uptake in the shoot by 11.0% for Cd, 30.0% for Pb, and 47.1% for Cu, respectively. In contrast, MPs caused a significant decrease (22.6%, 17.9-26.9%) in the shoot As accumulation. The type and dose of MPs were correlated with the accumulation of HMs. MPs increased available concentrations of Cd, Pb, and Cu, but decreased available As concentration in soils. Meanwhile, MPs addition significantly lowered soil pH. These findings may provide explanations for MPs-mediated effects on influencing the accumulation of HMs in plants. Using a machine learning approach, we revealed that soil pH and total HMs concentration are the major contributors affecting their accumulation in shoot. Overall, our study indicated that MPs may increase the environmental risks of HMs in agroecosystems, especially metal cations.
微塑料（MPs）和重金属（loid）s（HMs）的共同存在引起了越来越多的科学关注，因为它们广泛分布且具有环境毒性。然而，土壤-植物系统中 MPs 和 HMs 之间的相互作用仍不清楚。我们进行了一项荟萃分析，共包含 87 项独立研究的 3226 个观测值，以量化 MPs 添加对植物生物量和 HMS 积累的影响。MPs 和 HMs 的共同存在（除了 As）对植物生长产生协同毒性。MPs 分别使 Cd、Pb 和 Cu 在地上部分的吸收增加了 11.0%、30.0%和 47.1%。相比之下，MPs 导致地上部分 As 积累显著减少（22.6%，17.9-26.9%）。MPs 的类型和剂量与 HMs 的积累有关。MPs 增加了 Cd、Pb 和 Cu 的有效浓度，但降低了土壤中 As 的有效浓度。同时，MPs 添加显著降低了土壤 pH 值。这些发现可能为 MPs 介导的影响对影响植物中 HMs 积累的机制提供了解释。我们使用机器学习方法揭示了土壤 pH 值和总 HMs 浓度是影响其在地上部分积累的主要因素。总的来说，我们的研究表明 MPs 可能会增加农业生态系统中 HMs 的环境风险，尤其是金属阳离子。
