Assessment of toxicity and potential health risk from persistent pesticides and heavy metals along the Delhi stretch of river Yamuna.
Assessment of toxicity and potential health risk from persistent pesticides and heavy metals along the Delhi stretch of river Yamuna.
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DOI：
10.1016/j.envres.2021.111780
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发表时间：
2021-07
影响因子：
8.3
通讯作者：
M. Parween;A. Ramanathan;N. J. Raju
中科院分区：
文献类型：
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作者：
M. Parween;A. Ramanathan;N. J. Raju
本研究旨在评估亚穆纳河沿大城市德里污染最严重的一段河段的环境质量。进行这项研究是为了检查与河流生态系统中存在的持久性污染物有关的毒性和健康危害。从亚穆纳河河漫滩德里段同一地点采集84份沉积物和56份蔬菜样品，检测20种有机氯农药（OCPs）和9种重金属（Cd、Co、Cr、Cu、Fe、Mn、Ni、Pb和Zn）。对持久性有毒物质的有机和无机类别进行了监测和分析，以确定对当地人口构成的生态毒理学和饮食健康风险的程度。根据沉积物质量指标、富集系数、地积指数、污染程度和污染负荷指数进行生态毒理学评价。利用蔬菜中这些污染物的易位因子（TF）来评估饮食风险。还调查了食用蔬菜的致癌和非致癌健康风险。根据沉积物质量准则，对重金属的关注程度大于对OCPs的关注程度。DDT、Cd、Pb、Zn的浓度最高，达到3级关注，Cr、Ni的浓度最高，达到4级关注。沉积物样品Cd富集程度显著，Pb污染程度中等，分别用富集因子和污染因子（CF）表示。金属的CF顺序为Zn > Cd > Crdouble bondNi > Pbdouble bondCu。污染负荷指数最高的位置位于德里亚穆纳出口点。在分析Ni、Cr、Cu和Zn的大多数样品中，观察到TF值大于1。在蔬菜中，菠菜的金属污染最高。Cd、Ni和Pb在根系积累较多，Mn、Zn、Cu和Cr在茎部积累较多。在蔬菜中，大部分OCPs的易位因子都很高，这清楚地表明了OCPs的生物积累和对消费者的潜在健康风险。对食用蔬菜对人类的健康风险进行了非致癌性和致癌性评估。儿童食用萝卜（根和叶）和花椰菜的危害系数bbbb1显示无致癌风险。所有蔬菜（洋葱叶除外）的危害指数（HI）均超过1，证实累积风险较大。终生癌症风险（LCR）显示中度（菠菜，萝卜，甜菜根和花椰菜）到低水平（所有其他）对人类的致癌风险。γ-HCH, β- HCH, Hept, Hept Ep, Ald, p,p ' - ddt和Cr通过食物链暴露的癌症风险可以得到很好的证实。
The present study aims at the assessment of environmental quality of the most polluted stretch of river Yamuna along the megacity of Delhi. The study was conducted in order to examine toxicity and health hazards associated with persistent pollutants present in the fluvial ecosystem. Eighty four sediment and 56 vegetable samples from same locations were collected from the Delhi segment of river Yamuna flood plain in order to examine 20 organochlorine pesticides (OCPs) and 9 heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn). Both the organic and inorganic groups of persistent toxic substances were monitored and analysed for the extent of eco-toxicological as well as dietary health risks posed to the local population. Eco-toxicological assessment was done based on sediment quality guidelines, enrichment factor, geo-accumulation index, degree of contamination and Pollution Load Index. The dietary-risk was assessed with the help of translocation factors (TF) of these pollutants in vegetables. Carcinogenic and non-carcinogenic health risks from consumption of vegetables were also investigated.The level of concern for heavy metals was greater than that of OCPs as per the sediment quality guidelines. DDT, Cd, Pb and Zn had maximum concentrations corresponding to level 3 of concern, while Cr and Ni reached up to the highest i.e., 4th level of concern. Sediment samples were found to be enriched and contaminated significantly with Cd and moderately with Pb, as represented respectively by enrichment factors and contamination factors (CF). CF for metals lied in order Zn > Cd > Crdouble bondNi > Pbdouble bondCu. Pollution load index was highest at the location lying on the exit point of Yamuna in Delhi. TF values greater than 1 were observed in majority of samples analysed for Ni, Cr, Cu and Zn. Spinach topped among vegetables in terms of metal contamination. Cd, Ni and Pb accumulated more in the roots, as against Mn, Zn, Cu and Cr which had higher accumulation in the shoots. Translocation factors were substantially high in vegetables for most of the OCPs, clearly indicating bioaccumulation and potential health risk to the consumers. Health risk to humans was assessed for non-carcinogenic and carcinogenic potentials from ingestion of vegetables. Hazard Quotient (HQ) > 1 due to radish (roots and leaves) and cauliflower consumption in children indicated non-carcinogenic risk. Hazard Index (HI) beyond 1 for all the vegetables (except onion leaves) confirmed substantial cumulative risk. Lifetime cancer risk (LCR) revealed moderate (spinach, radish, beet root and cauliflower) to low (all the others) levels of carcinogenic risk to humans. Cancer risks from γ-HCH, β- HCH, Hept, Hept Ep, Ald, p,p’-DDT, and Cr exposure through the food chain could be well established.