The excess presence of heavy metals in water resources deteriorates the quality and has a high potential for bioaccumulation and environmental contamination. The study of heavy metals in water is essential because of their integration in the food chain and the potential for sublethal effects on aquatic and human life. To understand the extent of heavy metal pollution, a total of 64 groundwater samples (32 in each pre-and post-monsoon season) were collected around the Yamuna River's flood plains in the Delhi region. In this study, pollution indices and health risk assessment methodologies were used to estimate the significant threat to humans. In examined seasons, the sequence of heavy metal content in groundwater is Fe > Mn > Zn > B > As>Ni > Pb. The heavy metal pollution index (HPI) revealed that in the pre-and post-monsoon seasons, 53% and 44% (HPI >100), of groundwater samples are at high-risk zone respectively. 53% of pre-monsoon and 56% of post-monsoon samples were found highly polluted, according to the degree of contamination (C_d). Moreover, health risk assessment shows that hazard index (HI) values for heavy metals were found significantly high (HI >1) in groundwater samples inferring increased non-cancerous risk to the local community. The results imply that continuous exposure can lead to chronic diseases in the population residing in the study region. In both carcinogenic and non-carcinogenic assessments, children's hazard index and carcinogenic risk assessment (CR) scores were found higher. As a result, compared to adults in the study region, children are more vulnerable to potential health threats. The principal component analysis (PCA) method was used to figure out the origin of heavy metals, and it was found that As, Fe, Mn, and Zn come from non-anthropogenic sources, whereas mixed sources (natural and anthropogenic) may be responsible for B, Ni, and Pb presence. The results of the study will help to develop an effective strategy for environmental assessment and monitoring to control groundwater pollution of the Delhi urban environs.

水资源中过量存在的重金属会降低水质，并具有很高的生物积累和环境污染潜力。水中重金属的研究至关重要，因为它们整合到食物链中，并且可能对水生和人类生命产生亚致死影响。为了了解重金属污染的程度，在德里地区的亚穆纳河冲积平原周围共采集了 64 个地下水样本（每个季风前后各 32 个）。在这项研究中，污染指数和健康风险评估方法被用来估计对人类的重大威胁。在考察的季节，地下水中重金属含量的顺序是Fe > Mn > Zn > B > As > Ni > Pb。重金属污染指数（HPI）显示，在季风前和季风后，53%和44%（HPI>100）的地下水样本分别处于高风险区。根据污染程度（C_d）。此外，健康风险评估表明，地下水样本中重金属的危害指数 (HI) 值显着较高 (HI >1)，这表明对当地社区的非癌症风险增加。结果表明，持续接触可能导致研究区域内的人群患慢性病。在致癌性和非致癌性评估中，儿童危害指数和致癌风险评估（CR）得分较高。因此，与研究区域的成年人相比，儿童更容易受到潜在的健康威胁。采用主成分分析 (PCA) 方法找出重金属的来源，发现 As、Fe、Mn 和 Zn 来自非人为来源，而混合来源（自然和人为）可能是原因对于 B，Ni，和铅的存在。研究结果将有助于制定有效的环境评估和监测策略，以控制德里城市环境的地下水污染。