Cancer health risk indices statistics.

Economic expansion has led to an increase in new toxins in the environment, creating a global problem for managing both environmental and human health. This study aimed to quantify the concentration of heavy metals (HMs) in soils of the Kafr El-Sheikh Governorate, located in the northern Nile Delta, Egypt, and to evaluate potential health risks by integrating Geographic Information Systems (GIS) with multivariate statistical analyses. Soil samples from 27 sites were analysed for potentially toxic elements (As, Cd, Co, Cu, Fe, Mn, Ni, Pb, and Zn) using Inductively Coupled Plasma Mass Spectrometry. Soil pollution indices such as enrichment factor (EF), contamination factor (CF), and geoaccumulation index (Igeo) were assessed. In addition, non-carcinogenic and cancer risk indices were calculated. To identify the origins of HMs in the research area, Pearson’s bivariate correlation, principal component, and hierarchical cluster analyses (PCA) were used. The findings revealed that the mean HM concentrations (mg kg-1) were in the following order: Fe (10706 ± 2855)>Mn (697.53 ± 138.46)> As(210.07 ± 20.23)> Zn (207.40 ± 216.76)>Ni(112.43 ± 13.68)> Cu (87.15 ± 47.69)> Pb(31.11 ± 8.66)> Co(23.97 ± 5.96)> Cd (6.50 ± 5.62). The EF, CF, and Igeo indices indicated that the soils in the study area were contaminated with metals. The risk index values indicated moderate, considerable, and very high ecological risk, with a median value of 2060.40 (range: 192.95–5006.97). From PCA results, the possible sources of the metals in the arid soils included pesticides and chemical fertilizers, except for Mn, which appeared to originate from geogenic sources. Both children and adults had hazard quotient and Hazard index values less than one in all three exposure pathways, except for As in the ingestion pathway for children.. Furthermore, the total cancer risk (sum of ingestion, inhalation, and dermal contact pathways for each element) associated with children’s exposure to the elements under investigation was as follows: Pb (4.5E-02)> As (4.1E-03)> Ni (2.6E-03)> Cd (4.7E-05). Consequently, the largest cancer risk was determined to be from Pb. These results provide valuable information that emphasizes the need to mitigate pollution from potentially toxic elements in the Nile delta and minimize health concerns for the local population.

经济扩张导致环境中新出现的毒素数量持续攀升，为环境与人类健康的协同管理带来了全球性挑战。本研究旨在定量分析埃及尼罗河三角洲北部卡夫尔埃尔谢赫省（Kafr El-Sheikh Governorate）土壤中的重金属（heavy metals, HMs）含量，并通过整合地理信息系统（Geographic Information Systems, GIS）与多元统计分析方法，评估潜在健康风险。研究采用电感耦合等离子体质谱法，对27个采样点的土壤样本中的潜在有毒元素（砷(As)、镉(Cd)、钴(Co)、铜(Cu)、铁(Fe)、锰(Mn)、镍(Ni)、铅(Pb)与锌(Zn)）进行了检测分析。本研究还评估了富集系数(enrichment factor, EF)、污染系数(contamination factor, CF)及地质累积指数(geoaccumulation index, Igeo)等土壤污染指数，并计算了非致癌风险指数与致癌风险指数。为明确研究区域内重金属的来源，本研究采用皮尔逊双变量相关分析、主成分分析(principal component analysis, PCA)及系统聚类分析方法。研究结果显示，各重金属的平均含量（单位：mg·kg⁻¹）排序如下：铁Fe(10706±2855)＞锰Mn(697.53±138.46)＞砷As(210.07±20.23)＞锌Zn(207.40±216.76)＞镍Ni(112.43±13.68)＞铜Cu(87.15±47.69)＞铅Pb(31.11±8.66)＞钴Co(23.97±5.96)＞镉Cd(6.50±5.62)。富集系数、污染系数与地质累积指数的计算结果表明，研究区域土壤已受到重金属污染。生态风险指数结果显示区域土壤存在中等、显著及极高生态风险，其中位值为2060.40（取值范围：192.95~5006.97）。主成分分析结果表明，研究区干旱土壤中的重金属除锰Mn主要源自地质成因外，其余元素的潜在来源多为农药与化肥施用。在三种暴露途径下，儿童与成人的危害商数(hazard quotient, HQ)及危害指数(hazard index, HI)均小于1，但儿童经食入途径暴露于砷As的情况除外。此外，儿童经食入、吸入及皮肤接触三种途径暴露于目标重金属的总致癌风险排序如下：铅Pb(4.5×10⁻²)＞砷As(4.1×10⁻³)＞镍Ni(2.6×10⁻³)＞镉Cd(4.7×10⁻⁵)。由此可见，铅Pb是引发最高致癌风险的重金属。本研究结果可为尼罗河三角洲地区潜在有毒元素污染治理及降低当地居民健康风险提供重要科学依据。