School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
Environ Sci Pollut Res Int. 2022 Feb;29(6):8623-8637. doi: 10.1007/s11356-021-16088-3. Epub 2021 Sep 7.
Wastewater application for irrigation is a traditional and economic tool in developing nations. Yet prolonged use of wastewater for agricultural activities contributes to the accumulation of metals in both soil and vegetables. This study investigated the accumulation and contamination of vegetables with heavy metals ensuing from the application of wastewater from the Agra Canal and the associated risks posed to human health. Three sites across the Agra canal were selected for sampling (CW-1, CW-2, and CW-3), where untreated wastewater is being used to irrigate vegetables (spinach, coriander, radish, and garlic crops), for which tube-well water (TW) from a village served as the control site. Water, soil, and vegetable samples were collected from all sites. The presence in them of various metals, such as As, Pb, Cr, Mn, Cu, Zn, and Ni, was detected at all four sites. The greatest content of Mn was found in CW-1's water (7.91 mg/L), soil (633.77 mg/kg), and in spinach 368.12 (mg/kg) grown there. Significantly higher metal concentrations were observed in vegetables irrigated with wastewater than in tube-well-irrigated vegetables, with the metals ranked in accumulation as follows Mn > Zn > Ni > Cu > Cr > Pb > As. Our results also revealed that metal bioaccumulation varied enormously between foliar and non-foliar vegetables, as well as among the four sites. Daily metal intake (DMI) and health risk index (HRI) analyses suggested that children consuming contaminated vegetables are at higher risk than adults. The HRI for Mn, Ni, and Pb was above 1, which indicated significant health hazards to humans consuming the wastewater-irrigated vegetables. Moreover, the control site where tube-well water was used had an HRI below 1, signifying a negligible health risk for its consumption. Therefore, we may conclude that the extensive application of contaminated water for a longer duration would likely further increase metal accumulation in soil and vegetables that may be hazardous to living organisms.
污水灌溉在发展中国家是一种传统且经济的工具。然而，长期将污水用于农业活动会导致金属在土壤和蔬菜中积累。本研究调查了来自亚格拉运河的污水用于灌溉蔬菜时，蔬菜中重金属的积累和污染情况，以及对人类健康构成的相关风险。在亚格拉运河沿线选择了三个地点进行采样（CW-1、CW-2 和 CW-3），在这些地点，未经处理的污水被用于灌溉蔬菜（菠菜、香菜、萝卜和大蒜作物），而村庄的管井水（TW）则作为对照点。从所有地点采集了水、土壤和蔬菜样本。在这四个地点都检测到了各种金属，如砷、铅、铬、锰、铜、锌和镍。在 CW-1 的水中（7.91 毫克/升）、土壤（633.77 毫克/公斤）和那里种植的菠菜中（368.12 毫克/公斤）发现了最大含量的锰。用污水灌溉的蔬菜中金属浓度明显高于用管井水灌溉的蔬菜，金属的积累顺序如下：锰>锌>镍>铜>铬>铅>砷。我们的结果还表明，金属生物累积在叶菜和非叶菜之间以及四个地点之间差异很大。每日金属摄入量（DMI）和健康风险指数（HRI）分析表明，食用受污染蔬菜的儿童比成年人面临更高的风险。锰、镍和铅的 HRI 超过 1，这表明食用污水灌溉蔬菜对人类健康构成重大危害。此外，使用管井水的对照点的 HRI 低于 1，表明其食用风险可以忽略不计。因此，我们可以得出结论，长时间大量使用受污染的水可能会进一步增加土壤和蔬菜中的金属积累，这可能对生物造成危害。
