Ogunkunle Clement Oluseye, Ziyath Abdul M, Adewumi Faderera Esther, Fatoba Paul Ojo
Department of Plant Biology, Plant Diversity and Environmental Biology Unit, University of Ilorin, Ilorin, Nigeria,
Environ Monit Assess. 2015 May;187(5):281. doi: 10.1007/s10661-015-4441-6. Epub 2015 Apr 22.
Dietary uptake of heavy metals through the consumption of vegetables grown on polluted soil can have serious human health implications. Thus, the study presented in this paper investigated the bioaccumulation and associated dietary risks of Pb, Zn, and Cd present in vegetables widely consumed in Nigeria, namely amaranth and jute mallow, grown on soil irrigated with polluted water from Asa River. The study found that the soil was polluted with Zn, Pb, and Cd with Pb and Cd being contributed by polluted river, while Zn was from geogenic sources. The metal concentration in amaranth and jute mallow varied in the order of Zn > Pb > Cd and Zn > Pb ≈ Cd, respectively. Jute mallow acts as an excluder plant for Pb, Cd, and Zn. Consequently, the metal concentrations in jute mallow were below the toxic threshold levels. Furthermore, non-cancer human health risk of consuming jute mallow from the study site was not significant. In contrast, the concentrations of Pb and Cd in amaranth were found to be above the recommended safe levels and to be posing human health risks. Therefore, further investigation was undertaken to identify the pathways of heavy metals to amaranth. The study found that the primary uptake pathway of Pb and Cd by amaranth is foliar route, while root uptake is the predominant pathway of Zn in amaranth.
通过食用生长在受污染土壤上的蔬菜而摄入重金属，可能会对人类健康产生严重影响。因此，本文所呈现的研究调查了尼日利亚广泛食用的蔬菜（即苋菜和锦葵）中铅、锌和镉的生物累积情况以及相关的饮食风险，这些蔬菜生长在由阿萨河受污染水灌溉的土壤上。研究发现，土壤受到锌、铅和镉的污染，其中铅和镉来自受污染的河流，而锌来自地质源。苋菜和锦葵中的金属浓度分别以锌＞铅＞镉和锌＞铅≈镉的顺序变化。锦葵是一种对铅、镉和锌具有排斥作用的植物。因此，锦葵中的金属浓度低于毒性阈值水平。此外，食用研究地点锦葵对人类健康的非致癌风险并不显著。相比之下，苋菜中铅和镉的浓度高于推荐的安全水平，并对人类健康构成风险。因此，开展了进一步调查以确定重金属进入苋菜的途径。研究发现，苋菜吸收铅和镉的主要途径是叶部途径，而根部吸收是苋菜吸收锌的主要途径。
