ABSTRACT

While airborne particulate matter (PM) pollution is a serious problem for urban environments, it can be reduced through uptake by plant leaves. In this study, we investigated and compared the uptake of PM-bound toxic metals by different plant species. Enrichment factor (EF) and correlation analyses across different sample types indicated anthropogenic origins of these toxic metals with airborne source signatures. Scanning electron microscopy (SEM) analyses of both leaf surfaces (adaxial and abaxial) suggested that the micro-morphological properties of the leaf surface (e.g. stomata, trichomes, epicuticular wax, and epidermal appendages) control the accumulation of PM and associated metals in plant leaves. Senna siamea leaves showed the most micro-morphological variation as well as the maximum concentration of toxic metals. It was found that foliar uptake of PM-bound toxic metals is affected by leaf surface morphological characteristics. Our results imply that plant speciation strategies can be used to help decrease PM pollution.

摘要

虽然空气中的颗粒物 (PM) 污染对城市环境来说是一个严重的问题，但它可以通过植物叶子的吸收来减少。在这项研究中，我们调查并比较了不同植物物种对 PM 结合的有毒金属的吸收。不同样本类型的富集因子 (EF) 和相关性分析表明这些有毒金属的人为来源具有空气传播源特征。对两个叶片表面（正面和背面）的扫描电子显微镜 (SEM) 分析表明，叶片表面的微形态特性（例如气孔、毛状体、表皮蜡和表皮附属物）控制植物中 PM 和相关金属的积累树叶。番泻叶叶片表现出最大的微观形态变化以及有毒金属的最大浓度。研究发现，PM 结合有毒金属的叶面吸收受叶片表面形态特征的影响。我们的结果表明植物物种形成策略可用于帮助减少 PM 污染。