Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus, Vehari, 61100, Pakistan.
Sahiwal Medical College, Sahiwal, Punjab, Pakistan.
Environ Geochem Health. 2023 Dec;45(12):8929-8942. doi: 10.1007/s10653-022-01351-4. Epub 2022 Aug 10.
The risk assessment of trace elements has received substantial attention for the achievement of UN Sustainable Developmental Goals (UN-SDGs). The present study aimed to evaluate health and ecological risks associated with trace element accumulation in Brassica oleracea under wastewater irrigations from three different areas. This study, for the first time, compared the pros and cons of mixed water crop irrigation (wastewater with fresh/groundwater). A pot experiment was conducted to evaluate the buildup of eight trace elements (As, Cu, Cd, Mn, Fe, Pb, Ni and Zn) in soil and B. oleracea plants irrigated with wastewater alone and mixed with fresh/groundwater. Specific ecological [degree of contamination (C), potential ecological risk index (PERI), pollution load index (PLI), geo-accumulation index (I)], phytoaccumulation [bioconcentration factor (BCF) and transfer factor (TF)] and health risk models [chronic daily intake (CDI), hazard quotient (HQ), cancer risk (CR)] were applied to assess the overall contamination of trace elements in the soil-plant-human system. Moreover, these indices were compared with the literature data. The concentration of Cd, Fe and Mn exceeded the threshold limits of 10, 500 and 200 mg kg, respectively, for agricultural soil. Overall, all the irrigation waters caused significant pollution load in soil indicating high ecological risk (C > 24, PERI > 380, Igeo > 5, PLI > 2). Not all the mixing treatments caused a reduction in trace element buildup in soil. The mixing of wastewater-1 with either groundwater or freshwater increased trace element levels in the soil as well as risk indices compared to wastewater alone. The BCF and TF values were > 1, respectively, for 66% and 7% treatments. Trace element concentration in plants and associated health risk were minimized in mixed wastewater treatments. There were 22% and 32% reduction in HQ and CR when wastewater was mixed with freshwater and 29% and 8% when mixed with groundwater. Despite total reduction, a great variation in % change in risk indices was observed with respect to the area of wastewater collection. Therefore, mixed water irrigation may be a good management strategy, but its recommendation depends on soil properties and composition of waters used for mixing. Moreover, it is recommended that the freshwater and wastewater of the particular area may be continuously monitored to avoid potential associated health hazards.
微量元素的风险评估受到了广泛关注，以实现联合国可持续发展目标（UN-SDGs）。本研究旨在评估在三种不同地区的污水灌溉下，甘蓝中微量元素积累所带来的健康和生态风险。本研究首次比较了混合水作物灌溉（污水与新鲜/地下水混合）的优缺点。通过盆栽试验，评估了单独用污水以及与新鲜/地下水混合灌溉时，土壤和甘蓝植物中八种微量元素（As、Cu、Cd、Mn、Fe、Pb、Ni 和 Zn）的积累情况。应用特定的生态[污染程度（C）、潜在生态风险指数（PERI）、污染负荷指数（PLI）、地积累指数（I）]、植物累积[生物浓缩系数（BCF）和转移系数（TF）]和健康风险模型[慢性日摄入量（CDI）、危害商数（HQ）、癌症风险（CR）]来评估土壤-植物-人类系统中微量元素的整体污染情况。此外，还将这些指数与文献数据进行了比较。Cd、Fe 和 Mn 的浓度分别超过了农业土壤中 10、500 和 200mgkg 的阈值限制。总体而言，所有灌溉用水都会导致土壤中的污染负荷显著增加，表明生态风险很高（C>24、PERI>380、Igeo>5、PLI>2）。并非所有混合处理都会降低土壤中微量元素的积累。与单独使用污水相比，污水 1 与地下水或淡水混合会增加土壤中的微量元素水平以及风险指数。BCF 和 TF 值分别大于 1，分别有 66%和 7%的处理达到了这一数值。在混合污水处理中，植物中微量元素的浓度和相关的健康风险最小。当污水与淡水混合时，HQ 和 CR 分别降低了 22%和 32%，当与地下水混合时，HQ 和 CR 分别降低了 29%和 8%。尽管总风险有所降低，但风险指数的变化百分比在不同污水收集区之间存在很大差异。因此，混合水灌溉可能是一种很好的管理策略，但需要根据土壤性质和混合用水的组成来推荐。此外，建议对特定地区的淡水和污水进行持续监测，以避免潜在的相关健康危害。
