为了解观赏性植物对土壤重金属污染的修复效果,以开封市5种菊花(金皇后、墨菊、孔雀草、粉旭桃、玛格丽特菊)为研究对象,分析菊花以及土壤样品中镉(Cd)、铬(Cr)、铜(Cu)、铅(Pb)、锌(Zn)等5种重金属元素的含量,分析菊花对土壤重金属的富集、转移能力.采用单因子指数法、内梅罗综合指数法评价土壤环境质量,并采用模糊综合评价法进一步分析菊花带来的环境效益.结果表明,土壤中5种重金属的含量由大到小为:Zn Pb Cu Cr Cd,土壤重金属为轻度污染,且Cd对综合指数贡献最大;富集能力方面,所选菊花对5种重金属均能够富集;转移能力方面,金皇后的能力最强,其由强到弱的排序为Cr Cd Pb Zn Cu;环境效益分析,以开封菊花为例,2016—2018年开封菊花日滞尘量、日释氧量、日固碳量随着菊花的增多而增强. 相似文献
The uptake, translocation, and human bioaccessibility of metals originating from atmospheric fine particulate matters (PM) after foliar exposure is not well understood. Lettuce (Lactuca sativa L.) plants were exposed to micronic PbO, CuO, and CdO particulate matters (PMs) by the foliar pathway and mature plants (6 weeks old) were analyzed in terms of: (1) metal accumulation and localization on plant leaf surface, and metal translocation factor (TF) and global enrichment factor (GEF) in the plants; (2) shoot growth, plant dry weight (DW), net photosynthesis (Pn), stomatal conductance (Gs), and fatty acid ratio; (3) metal bioaccessibility in the plants and soil; and (4) the hazard quotient (HQ) associated with consumption of contaminated plants. Substantial levels of metals were observed in the directly exposed edible leaves and newly formed leaves of lettuce, highlighting both the possible metal transfers throughout the plant and the potential for human exposure after plant ingestion. No significant changes were observed in plant biomass after exposure to PbO, CuO, and CdO-PMs. The Gs and fatty acid ratio were increased in leaves after metal exposure. A dilution effect after foliar uptake was suggested which could alleviate metal phytotoxicity to some degree. However, plant shoot growth and Pn were inhibited when the plants are exposed to PbO, and necrosis enriched with Cd was observed on the leaf surface. Gastric bioaccessibility of plant leaves is ranked: Cd?>?Cu?>?Pb. Our results highlight a serious health risk of PbO, CuO, and CdO-PMs associated with consumption of vegetables exposed to these metals, even in newly formed leaves in the case of PbO and CdO exposure. Finally, the study highlights the fate and toxicity of metal rich-PMs, especially in the highly populated urban areas which are increasingly cultivated to promote local food.