江苏省耕地土壤重金属健康风险强度空间集聚特征及影响因素

Spatial agglomeration characteristics and influencing factors of health risk intensity of heavy metals in cultivated soil in Jiangsu Province

【目的】在健康中国战略深入实施背景下,环境健康风险已逐步融入到土壤污染防治过程中,如何揭示省域土壤重金属健康风险强度的空间集聚特征和影响因素,对于维护土壤资源可持续利用、完善风险防控体系和保障区域人群健康至关重要。【方法】本文在优化了US EPA健康风险评估模型的基础上,明晰了江苏省耕地土壤重金属健康风险特征因子和不同县区健康风险强度,从地理学视角构建了包括加权标准差椭圆、莫兰指数和地理探测器在内的空间分析方法体系,揭示了健康风险强度的空间集聚特征和影响因素,并探讨了江苏省耕地土壤重金属健康风险管控对策。【结果】结果表明:(1)Cr、Pb和As是江苏省耕地土壤重金属健康风险特征因子,且对应的儿童致癌风险高于10^(-6)的点位占比分别为99.97%、74.24%和98.39%;(2)Cr、Pb和As在不同县域的健康风险强度变化范围为0.0158~0.6532、0.0002~0.0466和0.0025~0.3859,对应的综合健康风险强度变化范围为0.0256~1.0399,且江苏省北部县区对于其健康风险强度具有较高的影响,对应的影响程度顺序为As>Cr>Pb;(3)Cr、Pb、As及综合健康风险强度具有显著空间集聚特征,对应的全局莫兰指数分别为0.084、0.053、0.225和0.143,且以HH和LL空间聚类为主,其类型区数量占4种类型区的68.18%。(4)地均化肥施用量、居民受教育程度、道路密度和地均GDP等4个探测因子的q值均大于0.3,对于重金属健康风险强度的空间分异有较高的解释度,且探测因子间呈现出非线性增强和双因子增强作用。【结论】江苏省耕地土壤重金属健康风险强度评价与分析为环境与健康研究提供了新的思路,研究结果可为江苏省耕地土壤重金属健康风险管控策略的制定提供现实依据。

[Objective]Environmental health risk has become the focus of current global research due to the fact that environmental pollution causes harm to human health.The research on health risk of heavy metals in cultivated soil at the provincial level based on interdisciplinary perspectives is of great significance for expanding the understanding of environmental health risk,formulating the control strategies of health risk,and protecting public health.[Methods]Based on the theories of human-environment relationship,the essential connotation of environmental health risk,and spatial statistical analysis methods in geography,we constructed an analytical framework for health risk of heavy metals in the soil of cultivated land.The characteristic factors,the spatial agglomeration characteristics,and the influencing mechanism of health risk were analyzed.Furthermore,the key points for health risk control were identified.[Results]The results show that:(1)The health risk levels of heavy metals Cr,Pb,Cd,As,and Hg in the cultivated soil of Jiangsu Province are within acceptable range.But Cr,Pb,and As were the main risk characteristic factors and need to be controlled.(2)Heavy metals in cultivated soil in some counties of Northern Jiangsu Province had a greater impact on the relative health risk level than the rest parts of the province.The degree of influence of different characteristic risk factors for the region was As>Cr>Pb,and the spatial distribution generally presented a pattern of northeast>southwest.(3)As,Cr,Pb,and the comprehensive health risks showed a spatial agglomeration trend,and the spatial structure of agglomeration exhibited a high-high and low-low pattern.(4)The q values of the four detection factors areal average fertilizer application,residents’education level,road density,and areal average GDP were higher than 0.3,and any two detection factors showed either a nonlinear enhancement or a dual-factor enhancement effect.[Conclusion]The health risk intensity of heavy metals in cultivated soil puts forward a fresh thought on environment and health researchs,and the research results could provide the practical basis for formulating control strategies on heavy metals in cultivated soil in Jiangsu Province.