Assessing groundwater quality is critical to regional water resource conservation and human health safety, especially in areas with co-existence of toxic constituents fluoride (F⁻) and arsenic (As). In this study, fourteen groundwater samples were collected in Feng County, Northwestern Jiangsu Province to identify dominant contaminants and their spatial distribution and health risk. The composition and variation characteristics of major ions (K⁺, Na⁺, Ca²⁺, Mg²⁺, Cl⁻, SO₄²⁻, HCO₃⁻, and NO₃⁻) and trace elements (F⁻, As, and Mn) were analyzed. The hydrochemical results revealed that high F⁻ groundwater was mainly distributed in the northern areas whereas As-riched groundwater was primarily distributed in southern areas. Notably, over 85.7% and 21.4% of the shallow groundwater samples exceeded the drinking water quality standard of 1.5 mg/L for F⁻ and 10 µg/L for As, respectively. Based on the water quality index (WQI) appraisal result, 71.4% of the groundwater in the study area is classified as “poor”, and thus unsuitable for drinking directly. We assessed the human non-carcinogenic health risk of F⁻ (HQ_Fluoride) and As (HQ_Arsenic) and the carcinogenic health risk of As (CR_Arsenic). The calculated hazard quotient (HQ) for F⁻ indicated nearly all groundwater samples have an unacceptable risk (HQ > 1) for each age group. However, HQ_Arsenic values revealed that 28.6%, 21.4%, 21.4%, and 21.4% of groundwater samples posed potential non-carcinogenic health risks for infants, children, females, and males, respectively. The calculated results of CR_Arsenic showed that 0%, 21.4%, 28.6%, and 28.6% of groundwater samples posed unacceptable health risks (CR > 1.0 × 10⁻⁴) to infants, children, females, and males, respectively. The groundwater irrigation suitability assessment results showed that 21.4% of samples were doubtful to unsuitable for irrigation, and 85.7% owed magnesium hazards. The findings of this study will assist policymakers in formulating proper remedial policies and mitigation strategies to ensure the safety of drinking and irrigation water.

^{评价地下水质量对于区域水资源保护和人类健康安全至关重要，特别是在有毒成分氟化物（F -}）和砷（As）共存的地区。本研究在江苏省西北部丰县采集了 14 个地下水样品，以识别主要污染物及其空间分布和健康风险。主要离子（K ⁺、Na ⁺、Ca ²⁺、Mg ²⁺、Cl ^-、SO ₄ ²⁻、HCO ₃ ^-、NO ₃ ^-）和微量元素（F ^-、As 、 Mn）进行了分析。水化学结果表明，高F-^地下水主要分布在北部地区，而富砷地下水主要分布在南部地区。值得注意的是，超过85.7%和21.4%的浅层地下水样品中^F-和As分别超过饮用水水质标准1.5 mg/L和10 µg/L。根据水质指数（WQI）评价结果，研究区71.4%的地下水属于“劣质”水，不适合直接饮用。我们评估了 F ^-（HQ_氟化物）和 As（HQ_砷）的人类非致癌健康风险以及 As（CR_砷）的致癌健康风险。计算出的^F−危险商 (HQ)表明，几乎所有地下水样本对于每个年龄组都具有不可接受的风险 (HQ > 1)。然而，HQ_砷值显示，地下水样本中分别有 28.6%、21.4%、21.4% 和 21.4% 对婴儿、儿童、女性和男性构成潜在的非致癌健康风险。 CR_砷的计算结果显示，地下水样品中分别有0%、21.4%、28.6%和28.6%对婴儿、儿童、女性和男性构成不可接受的健康风险（CR > 1.0 × 10 ^-4 ）。地下水灌溉适宜性评价结果显示，21.4%的样品怀疑不适宜灌溉，85.7%的样品存在镁危害。这项研究的结果将帮助政策制定者制定适当的补救政策和缓解策略，以确保饮用水和灌溉水的安全。