Human activity and soil N impact spatial distribution patterns of soil heavy metal pollution in China

Soil heavy metal pollution has emerged as a critical environmental challenge in China. Despite growing concerns, the spatial distribution patterns and land-use pollution characteristics remain poorly characterized. This nationwide investigation analyzed 7 priority heavy metals (cadmium (Cd), arsenic (As), lead (Pb), zinc (Zn), copper (Cu), chromium (Cr) and nickel (Ni)) across 33 study sites, employing structural equation modeling and random forest analysis to quantify drivers for heavy metal pollution pattern. Our results showed that the spatial distribution pattern of heavy metal pollution in China was negatively correlated with latitude. Cd, As, Pb and Zn should be the priority heavy metals to be controlled, with Cd exceeding the national standard by as much as 27.3 %. In addition, compared with other land, industrial and mining storage land pollution is the most serious, should be given priority control. The structural equation model showed that human, soil and climate together explain 39 % of the variance of heavy metal pollution. Random forest analysis suggested that human activity and N had the greatest relative influence on heavy metal pollution evaluation indexes. These findings provide a scientific basis for developing targeted remediation strategies and implementing differentiated land use management programs.

土壤重金属污染已成为中国面临的一项严峻环境挑战。尽管社会各界对该问题的关注度持续提升，但土壤重金属污染的空间分布格局与土地利用污染特征仍未得到充分解析。本次全国性调查选取7类优先管控重金属（镉（Cd）、砷（As）、铅（Pb）、锌（Zn）、铜（Cu）、铬（Cr）及镍（Ni）），在33个研究点位开展采样分析，采用结构方程模型（structural equation modeling）与随机森林分析（random forest analysis）方法量化驱动重金属污染格局的影响因子。研究结果显示，中国土壤重金属污染的空间分布格局与纬度呈显著负相关。其中镉（Cd）、砷（As）、铅（Pb）与锌（Zn）为优先管控重金属，镉的含量最高超出国家标准27.3%。此外，相较于其他土地利用类型，工矿仓储用地的重金属污染程度最为严重，需优先开展治理。结构方程模型结果表明，人类活动、土壤属性与气候因素共同解释了39%的重金属污染变异。随机森林分析显示，人类活动与氮素（N）对重金属污染评价指标的相对影响程度最高。本研究结果可为制定精准化修复策略与实施差异化土地利用管理方案提供科学依据。

搜集汇总

背景与挑战

背景概述

该数据集研究了人类活动和土壤氮对中国土壤重金属污染空间分布模式的影响，覆盖7种优先重金属在33个站点的分析，发现污染与纬度负相关，镉超标最严重且工业用地污染突出。分析表明人类活动、土壤和气候因素共同驱动污染，其中人类活动和氮的影响最大，为针对性修复和土地利用管理提供科学依据。