Patel Kajal, Chaurasia Meenakshi, Rao Kottapalli Sreenivasa
Natural Resource Management Lab (306), Department of Botany, University of Delhi, New Delhi, 110007, India.
Environ Sci Pollut Res Int. 2023 Feb;30(10):27622-27635. doi: 10.1007/s11356-022-24157-4. Epub 2022 Nov 16.
Heavy metals beyond their permissible limits are major contaminants and causes of concern due to their persistent nature and health hazards. Several studies validated the utilization of plants as biomonitors and bioaccumulators for heavy metal pollution. Therefore, this study was conducted to examine the proficiency for heavy metal monitoring and mitigation by commonly found plant species in urban areas of Delhi. For this objective, four sites (viz., control, residential, commercial, and industrial) and sixteen usually growing plant species were selected. Four heavy metals, i.e., lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn), were analysed for soil and dust from each site, and leaf samples from each plant, at all sites, and various other parameters were calculated. Among the four elements, Pb and Cd showed maximum geoaccumulation and contamination at all sites. Pollution load index (PLI) values for both soil and dust indicated that industrial sites (1.78, 2.15) were most contaminated followed by commercial (1.52, 1,87), residential (1.41, 1.67), and control (1.22, 1.37) sites. Concentrations of Pb, Cu, and Zn were found to be highest in Morus alba, while Cd concentrations were found to be highest in Millettia pinnata (L.) Panigrahi. From various analyses, we concluded that commonly found plant species such as Ficus religiosa L., Terminalia arjuna (Roxb. Ex DC.) Wight &Arn., Morus alba L., Prosopis juliflora (Sw.) DC., and M. pinnata proved to be exceptional biomonitors and bioaccumulators for heavy metals in urban areas. Therefore, these plant species are highly recommended for plantation in urban areas for decontamination of the air and soil by mitigating heavy metal pollution.
超出允许限度的重金属是主要污染物，因其持久性和健康危害而备受关注。多项研究证实植物可作为重金属污染的生物监测器和生物累积器。因此，本研究旨在考察德里市区常见植物物种对重金属的监测和缓解能力。为此，选取了四个地点（即对照点、居民区、商业区和工业区）以及16种常见植物物种。对每个地点的土壤、灰尘以及所有地点每种植物的叶片样本分析了四种重金属，即铅（Pb）、镉（Cd）、铜（Cu）和锌（Zn），并计算了各种其他参数。在这四种元素中，Pb和Cd在所有地点均表现出最大的地累积和污染程度。土壤和灰尘的污染负荷指数（PLI）值表明，工业场地（1.78, 2.15）污染最严重，其次是商业场地（1.52, 1.87）、居民区场地（1.41, 1.67）和对照场地（1.22, 1.37）。发现桑（Morus alba）中Pb、Cu和Zn的浓度最高，而镉浓度在羽叶决明（Millettia pinnata (L.) Panigrahi）中最高。通过各种分析，我们得出结论，诸如菩提树（Ficus religiosa L.）、诃子（Terminalia arjuna (Roxb. Ex DC.) Wight & Arn.）、桑（Morus alba L.）、牧豆树（Prosopis juliflora (Sw.) DC.）和羽叶决明等常见植物物种被证明是城市地区重金属的优秀生物监测器和生物累积器。因此，强烈推荐在城市地区种植这些植物物种，以通过减轻重金属污染来净化空气和土壤。
