College of Resources and Safety, Chongqing Vocational Institute of Engineering, Chongqing, 402260, China.
Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, 400715, China.
Sci Rep. 2022 Jul 16;12(1):12196. doi: 10.1038/s41598-022-16177-4.
Investigation and assessment of farmland pollution require an efficient method to identify heavy metal (HM) pollutants and their sources. In this study, heavy metals (HMs) in farmland were determined efficiently using high-precision X-ray fluorescence (HDXRF) spectrometer. The potential ecological risk and health risk of HMs in farmland near eight villages of Wushan County in China were quantified using an integrated method of concentration-oriented risk assessment (CORA) and source-oriented risk assessment (SORA). The CORA results showed that Cd in farmland near the villages of Liuping (LP) and Jianping (JP) posed a "very high" potential ecological risk, which is mainly ascribed to soil Cd (single potential ecological risk index ([Formula: see text]) of Cd in villages LP and JP, [Formula: see text] = 2307 and 568 > 320). A "moderate" potential ecological risk was present in other six villages. The overall non-carcinogenic risk (hazard index (HI) = 1.2 > 1) of HMs for children in village LP was unacceptable. The contributions of HMs decrease in the order of Cr > As > Cd > Pb > Ni > Cu > Zn. The total carcinogenic risk (TCR = 2.1 × 10 > 1.0 × 10) of HMs in village LP was unacceptable, with HMs contributions decreasing in the order of Cr > Ni > Cd > As > Pb. Furthermore, three source profiles were assigned by the positive matrix factorization: F1: agricultural activity; F2: geological anomaly originating from HMs-rich rocks; F3: the natural geological background. According to the results of SORA, F2 was the highest contributor to PER in village LP, up to 64.4%. Meanwhile, the contributions of three factors to HI in village LP were 19.0% (F1), 53.6% (F2), and 27.4% (F3), respectively. It is worth noting that TCR (1.2 × 10) from F2 surpassed the threshold of 1.0 × 10, with an unacceptable carcinogenic risk level. As mentioned above, the HM pollutants (i.e., Cd and Cr) and their main sources (i.e., F2) in this area should be considered. These results show that an integrated approach combining risk assessments with the determination of HM concentration and identification of HM source is effective in identifying HM pollutants and sources and provides a good methodological reference for effective prevention and control of HM pollution in farmland.
利用高精度 X 射线荧光（HDXRF）光谱仪高效测定农田重金属（HM）污染物及其来源。采用浓度导向风险评估（CORA）和来源导向风险评估（SORA）相结合的综合方法，定量评估中国巫山县 8 个村庄附近农田重金属（HM）的潜在生态风险和健康风险。CORA 结果表明，村庄 Liuping（LP）和 Jianping（JP）附近农田的 Cd 具有“很高”的潜在生态风险，主要归因于土壤 Cd（单个潜在生态风险指数 [Formula: see text]），[Formula: see text] = 2307 和 568>320。其他六个村庄则存在“中度”潜在生态风险。LP 村儿童的非致癌风险（危害指数（HI）= 1.2>1）不可接受。HM 的非致癌风险（HI）按 Cr>As>Cd>Pb>Ni>Cu>Zn 的顺序递减。LP 村总致癌风险（TCR = 2.1×10>1.0×10）不可接受，HM 的致癌风险（TCR）按 Cr>Ni>Cd>As>Pb 的顺序递减。此外，正矩阵因子分析（PMF）确定了三个源谱：F1：农业活动；F2：源自富含重金属岩石的地质异常；F3：自然地质背景。根据 SORA 的结果，F2 是 LP 村 PER 的最大贡献者，高达 64.4%。同时，F1、F2 和 F3 对 LP 村 HI 的贡献分别为 19.0%、53.6%和 27.4%。值得注意的是，F2 的 TCR（1.2×10）超过了 1.0×10 的阈值，具有不可接受的致癌风险水平。如前所述，该地区应考虑重金属污染物（即 Cd 和 Cr）及其主要来源（即 F2）。结果表明，结合风险评估与重金属浓度测定和重金属源识别的综合方法，可有效识别重金属污染物和来源，为有效防治农田重金属污染提供了良好的方法学参考。
