Human activities and the increasing emphasis on coastal protection contribute to the diversity and evolution of intertidal soil. But, less is known about the influence of soil evolution on the heavy metal risk in intertidal zones. In this study, soil samples were collected from three kinds of intertidal zone in the Pearl River Estuary, including bare beach (BB), a spartina growing area (SGA), and a mangrove growing area (MGA), to reveal the influence of key factors on the heavy metal risk. The results showed that the highest concentrations of Cd, Zn, Pb, Cu, Ni, and Cr mainly existed in the surface layer of SGA and MGA and decreased with depth, reaching 3.57, 365.26, 91.24 95.12, 58.47, and 111.35 mg kg⁻¹, respectively. Residual fractions were the main geochemical fractions and increased with depth, while exchangeable fractions showed the opposite trend. Based on the geoaccumulation index, soils were moderately to extremely polluted by Cd and partially to moderately polluted by Zn, Cu, and Ni. Cd had high potential adverse effects (ranging from 25.29 to 45) in MGA according to the risk assessment code. Correlation and principal component analyses indicated that soil organic carbon (SOC), clay, pH, Fe, and Mg were the key factors that affected the heavy metal risk. Linear regression revealed that SOC and clay were positively correlated with the pollution level of heavy metals, while clay and Fe were positively correlated with the ecological risk. Consequently, the variation in properties due to intertidal soil evolution may modulate the risk of heavy metals.

中文翻译：

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珠江口三种潮间带土壤演变对重金属风险的影响

人类活动和对沿海保护的日益重视促进了潮间带土壤的多样性和演变。但是，关于潮间带土壤演变对重金属风险的影响知之甚少。在这项研究中，从珠江口的三种潮间带采集土壤样本，包括裸露海滩（BB），斯巴提纳（Spartina）种植区（SGA）和红树林种植区（MGA），以揭示关键因素的影响。重金属风险的因素。结果表明，镉，锌，铅，铜，镍，和Cr的最高浓度主要存在于SGA和MGA的表面层和与深度减小，达到3.57，365.26，91.24 95.12，58.47和111.35毫克公斤^{- 1个}， 分别。残余馏分是主要的地球化学馏分，随深度增加而增加，而可交换馏分则呈现相反的趋势。根据地质累积指数，土壤受到镉的中等至极度污染，而受到锌，铜和镍的部分至中等污染。根据风险评估代码，镉在MGA中具有很高的潜在不良影响（范围从25.29到45）。相关性和主成分分析表明，土壤有机碳（SOC），粘土，pH，Fe和Mg是影响重金属风险的关键因素。线性回归表明，SOC和黏土与重金属污染水平呈正相关，而黏土和Fe与生态风险呈正相关。所以，