典型矿冶城市土壤重金属累积驱动因子研究和概率风险评估

doi:10.13745/j.esf.sf.2023.11.46

摘要/Abstract

摘要：

明确土壤重金属来源及其健康风险是有效开展土壤污染风险管控的重要环节。本研究以某典型矿冶城市作为研究案例,采用地累积指数法(I_geo)评价8种重金属(As、Cd、Cr、Cu、Ni、Pb、Zn和Hg)的污染特征,结合相关分析和正定矩阵因子分解(PMF)模型分析土壤重金属的潜在来源,进一步应用冗余分析探索土壤重金属累积的环境驱动因子,借助健康风险评估模型量化土壤重金属的风险水平。I_geo结果显示,Cd污染处于中度污染水平,Cu、Pb和Zn污染处于轻度污染水平。依据PMF模型确定研究区域土壤重金属存在4个可能的污染来源,结合相关分析和区域特征,判断污染来源包括铅锌矿采选和冶炼源(Cd和Pb)、自然源与铜矿采选和冶炼的混合源(Cr、Ni、Cu和Pb)、有色金属冶炼排放源(Hg)、金矿采选和冶炼源(As),其中自然源和铜矿采选、冶炼的混合源是最主要的来源(70.10%)。冗余分析进一步明确,阳离子交换量、含水率和企业距离是土壤重金属累积的关键驱动因子。从健康风险评估结果来看,研究区域土壤重金属对儿童存在不可接受的致癌风险(概率为15.21%),对成人的致癌风险以及对儿童和成人的非致癌风险处于可接受风险水平。值得注意的是,As是研究区域主要的致癌因子,致癌风险的95%分位值(1.75×10^-4)超过可接受风险阈值1×10^-4。上述研究结果可为研究区域土壤重金属的优先管控和污染防治提供数据支撑。

关键词: 矿冶城市, 土壤重金属, 源解析, PMF模型, 冗余分析, 概率风险评估

Abstract:

Understanding the sources of heavy metals in soils and the associated health risks is essential for effective risk management. In this study, taking a typical mining community as an example, the characteristics of soil contamination by heavy metals As, Cd, Cr, Cu, Ni, Pb, Zn, and Hg are evaluated using geo-accumulation index (I_geo). The potential sources of heavy metals are analyzed through correlation analysis in combination with positive matrix factorization (PMF) analysis. The results are applied to identify the driving factors for heavy metal accumulation in soils by redundancy analysis (RDA) and to quantify the associated health risk using the health risk assessment model. The I_geo results indicated a moderate level of Cd accumulation and low levels of Cu, Pb and Zn accumulation. Four potential sources of heavy metals in the study area were identified based on the PMF model. Combined with correlation analysis and regional pollution characteristics the four sources were clarified—they were Pb-Zn ore extraction and smelting (Cd, Pb), mixed sources (natural sources+copper ore mining and smelting) (Cr, Ni, Cu, Pb), non-ferrous metal smelting emission (Hg), and gold ore mining and smelting (As), with mixed sources being the dominant sources (70.10%). Based on RDA results, the key driving factors for heavy metal accumulation were cation exchange, soil moisture and distance to mines. According to the health risk assessment, heavy metal contamination in soils of the study area posed unacceptable carcinogenic hazards to children (probability of 15.21%), and carcinogenic health risks to adults and non-carcinogenic health risks to children and adults were at an acceptable risk level. Notably As was the main carcinogenic risk factor in the study area, and the 95th percentile risk (1.75E-4) exceeded the acceptable risk threshold (1E-4). The above findings can provide data support for priority control and prevention of heavy metal pollution in soils of the study area.

Key words: mining community, soil heavy metals, source analysis, PMF model, redundancy analysis, probabilistic risk assessment

中图分类号:

X53
X825

丁祥, 袁贝, 杜平, 刘虎鹏, 张云慧, 陈娟. 典型矿冶城市土壤重金属累积驱动因子研究和概率风险评估[J]. 地学前缘, 2024, 31(2): 31-41.

DING Xiang, YUAN Bei, DU Ping, LIU Hupeng, ZHANG Yunhui, CHEN Juan. Heavy metal accumulation in soils of a typical mining community: Driving factors and probabilistic health risk assessment[J]. Earth Science Frontiers, 2024, 31(2): 31-41.

图/表 12

图1 研究区域土壤采样点分布图

Fig.1 Distribution of soil sampling sites in the study area

表1 概率风险评估模型参数的含义和取值

Table 1 The meanings and values of probabilistic risk assessment model parameters

参数性质项		各参数具体特征
名称		暴露频率 (EF)	皮肤黏附系数 (AF)	体重 (BW)	颗粒物释放因子 (PEF)	暴露期 (ED)	土壤颗粒摄入速率 (IngR)	土壤颗粒吸入速率 (InhR)	平均暴露时间 (Atca)	皮肤暴露表面积 (SA)	皮肤吸收因子 (ABF)
单位		d/a	mg/(cm²·d)	kg	m³/kg	a	mg/d	m³/d	d	m²
分布		三角	对数正态	正态	单点	均匀	三角	对数正态	单点	单点	单点
取值	成人	TRI (180, 345, 365)	LN (0.49, 0.54)	N (57.03, 1.18)	1.36E+09	UN (0, 24)	TRI (4, 30, 52)	LN (16.57, 4.05)	2 190	0.49	0.001
取值	儿童	TRI (180, 345, 365)	LN (0.65, 1.20)	N (16.68, 1.48)	1.36E+09	UN (0, 6)	TRI (66, 103, 161)	LN (7.19, 1.62)	9 125	0.23	0.001
数据来源文献		[22]	[22]	[23]	[23]	[24]	[25]	[25]	[25]	[26]	[26]

表2 重金属毒性参数取值(据文献[27⇓-29])

Table 2 The values of heavy metal toxicity parameters. Adapted from [27⇓-29].

重金属元素	RfD/(mg·kg^-1·d^-1)			SF/(kg·d·mg^-1)
	RfD_ing	RfD_der	RfD_inh	SF_ing	SF_der	SF_inh
As	3.00×10^-4	1.23×10^-4	3.01×10^-4	1.50×10⁰	3.66×10⁰	1.51×10¹
Cd	1.00×10^-3	1.00×10^-5	1.00×10^-5	5.01×10^-1	2.00×10¹	6.30×10⁰
Cr	3.00×10^-3	1.23×10^-4	2.86×10^-5	8.50×10^-3		4.20×10¹
Cu	4.00×10^-2	1.20×10^-2	4.02×10^-2
Ni	2.00×10^-2	5.40×10^-3	2.06×10^-2			8.4×10^-1
Pb	3.50×10^-3	5.25×10^-4	3.52×10^-3	8.50×10^-3
Zn	3.00×10^-1	6.00×10^-2	6.00×10^-2
Hg	3.00×10^-4	2.10×10^-5	8.57×10^-5

图2 研究区域表层土壤重金属含量统计图断划线表示研究区域土壤重金属背景值(据文献[30]);双点断划线表示土壤污染风险筛选值(据文献[31]) 。

Fig.2 Statistics plots of heavy metal content in topsoil of the study area

图3 研究区域土壤重金属地累积指数箱线图

Fig.3 Box plots of the geo-accumulation index of heavy metals in the study area

表3 研究区域土壤重金属相关性分析结果

Table 3 Results of the correlation analysis of heavy metals in the study area

重金属元素	土壤各重金属元素含量间的相关系数
重金属元素	As	Cd	Cr	Cu	Ni	Pb	Zn	Hg
As	1	0.465^***	0.416^***	0.597^***	0.354^***	0.395^***	0.338^***	0.210^***
Cd		1	0.196^**	0.446^***	0.415^*	0.612^***	0.407^***	0.244^***
Cr			1	0.604^***	0.913^***	0.065	0.307^***	0.192^**
Cu				1	0.621^***	0.407^***	0.584^***	0.258^***
Ni					1	0.020	0.411^***	0.135^*
Pb						1	0.318^***	0.242^***
Zn							1	0.287^***
Hg								1

图4 基于PMF模型的研究区域土壤重金属污染源贡献率图中圆圈大小代表重金属对各因子贡献的高低。

Fig.4 Source contribution ratios of soil heavy metals in the study area based on PMF model

图5 土壤重金属与驱动因子之间的相关分析和RDA结果

Fig.5 Results of correlation analysis and RDA between soil heavy metals and driving factors

表4 应用蒙特卡罗模拟研究区域土壤重金属含量的分布函数

Table 4 Fitting distribution function of soil heavy metal concentration by MCS

重金属元素	分布函数	分布函数关键参数/(mg·kg^-1)
重金属元素	分布函数	均值	标准差
As	对数正态	12.48	11.52
Cd	对数正态	0.53	0.41
Cr	对数正态	68.69	29.39
Cu	对数正态	51.11	35.89
Ni	对数正态	33.05	14.14
Pb	对数正态	55.66	30.85
Zn	对数正态	120.51	45.23
Hg	对数正态	0.16	0.15

图6 研究区域成人和儿童不同暴露途径下致癌风险的概率分布 a—经口摄入致癌风险;b—皮肤接触致癌风险;c—呼吸吸入致癌风险;d—总致癌风险。虚线表示健康风险概率分布的95%分位。

Fig.6 Probability distributions of carcinogenic risk under different exposure routes for adults and children in the study area

图7 研究区域成人和儿童不同暴露途径下非致癌风险的概率分布 a—经口摄入非致癌风险;b—皮肤接触非致癌风险;c—呼吸吸入非致癌风险;d—总非致癌风险。虚线表示健康风险概率分布的95%分位。

Fig.7 Probability distributions of non-carcinogenic risk under different exposure routes for adults and children in the study area

图8 研究区域不同土壤重金属健康风险的95%分位值 a—致癌风险;b—非致癌风险。

Fig.8 The 95th percentile values of health risks for different soil heavy metals in the study area

参考文献 48

[1]	ZHAO F J, MA Y, ZHU Y G, et al. Soil contamination in China: current status and mitigation strategies[J]. Environmental Science and Technology, 2015, 49(2): 750-759.
[2]	GILLER K E, WITTER E, MCGRATH S P. Toxicity of heavy metals to microorganisms and microbial processes in agricultural soils: a review[J]. Soil Biology and Biochemistry, 1998, 30(10/11): 1389-1414.
[3]	ZERIZGHI T, GUO Q J, TIAN L Y, et al. An integrated approach to quantify ecological and human health risks of soil heavy metal contamination around coal mining area[J]. Science of the Total Environment, 2022, 814: 152653.
[4]	WANG Y T, GUO G H, ZHANG D G, et al. An integrated method for source apportionment of heavy metal(loid)s in agricultural soils and model uncertainty analysis[J]. Environmental Pollution, 2021, 276: 116666.
[5]	WANG J Y, CAI Y, YANG J, et al. Research trends and frontiers on source appointment of soil heavy metal: a scientometric review (2000-2020)[J]. Environmental Science and Pollution Research, 2021, 28(38): 52764-52779.
[6]	廖晓勇, 陈同斌, 武斌, 等. 典型矿业城市的土壤重金属分布特征与复合污染评价: 以“镍都” 金昌市为例[J]. 地理研究, 2006, 25(5): 843-852.
[7]	ALI H, KHAN E, ILAHI I. Environmental chemistry and ecotoxicology of hazardous heavy metals: environmental persistence, toxicity, and bioaccumulation[J]. Journal of Chemistry, 2019, 2019: 6730305.
[8]	LI Z Y, MA Z W, VAN DER KUIJP T J, et al. A review of soil heavy metal pollution from mines in China: pollution and health risk assessment[J]. Science of the Total Environment, 2014, 468/469: 843-853.
[9]	陈雅丽, 翁莉萍, 马杰, 等. 近十年中国土壤重金属污染源解析研究进展[J]. 农业环境科学学报, 2019, 38(10): 2219-2238.
[10]	US Environmental Protection Agency. EPA Positive Matrix Factorization (PMF) 5.0 fundamentals and user guide[EB/OL]. (2023-04-05) [2023-11-10]. https://www.epa.gov/sites/default/files/2015-02/documents/pmf_5.0_user_guide.pdf.
[11]	ANAMAN R, PENG C, JIANG Z C, et al. Identifying sources and transport routes of heavy metals in soil with different land uses around a smelting site by GIS based PCA and PMF[J]. Science of the Total Environment, 2022, 823: 153759.
[12]	李军, 李旭, 李开明, 等. 黄河流域农田土壤重金属污染特征及其优先控制源分析[J]. 环境科学, 2024, 45(3): 1724-1738.
[13]	XIAO L, GUAN D S, CHEN Y J, et al. Distribution and availability of heavy metals in soils near electroplating factories[J]. Environmental Science and Pollution Research, 2019, 26(22): 22596-22610.
[14]	潘泳兴, 陈盟, 王櫹橦. 典型铅锌矿流域土壤重金属累积与分布的影响因素分析[J]. 环境科学, 2023, 44(11): 6071-6084.
[15]	US Environmental Protection Agency. Risk assessment guidance for superfund: Volume III: Part A, process for conducting probabilistic risk assessment[R]. Washington: Office of Emergency and Remedial Response, US Environmental Protection Agency, 2001.
[16]	DONG Z M, LIU Y J, DUAN L C, et al. Uncertainties in human health risk assessment of environmental contaminants: a review and perspective[J]. Environment International, 2015, 85: 120-132.
[17]	杨湜烟, 刘杏梅, 徐建明. 土壤重金属污染健康风险评估新视角: 概率风险评估的源起及展望[J]. 土壤学报, 2022, 59(1): 28-37.
[18]	QU C S, SUN K, WANG S R, et al. Monte Carlo simulation-based health risk assessment of heavy metal soil pollution: a case study in the Qixia mining area, China[J]. Human and Ecological Risk Assessment, 2012, 18(4): 733-750.
[19]	YUAN B, CAO H L, DU P, et al. Source-oriented probabilistic health risk assessment of soil potentially toxic elements in a typical mining city[J]. Journal of Hazardous Materials, 2023, 443: 130222.
[20]	国家环境保护总局. 土壤环境监测技术规范: HJ/T 166—2004[S]. 北京: 中国环境出版社, 2004.
[21]	MULLER G. Index of geoaccumulation in sediments of the Rhine River[J]. Geojournal, 1969, 2: 108-118.
[22]	BREIMAN L. Random forests[J]. Machine Learning, 2001, 45(1): 5-32.
[23]	黄剑波, 姜登登, 温冰, 等. 基于蒙特卡罗模拟的铅锌冶炼厂周边农田土壤重金属健康风险评估[J]. 环境科学, 2023, 44(4): 2204-2214.
[24]	US Environmental Protection Agency. The exposure factors handbook (2011 Edition)[EB/OL]. (2011-10-03)[2023-11-10]. https://www.epa.gov/expobox/about-exposure-factors-handbook.
[25]	SUN J X, ZHAO M L, HUANG J L, et al. Determination of priority control factors for the management of soil trace metal(loid)s based on source-oriented health risk assessment[J]. Journal of Hazardous Materials, 2022, 423: 127116.
[26]	中华人民共和国生态环境部. 建设用地土壤污染风险评估技术导则: HJ 25.3—2019[S]. 北京: 中国环境出版集团, 2019.
[27]	SUN R G, GAO Y, YANG Y. Leaching of heavy metals from lead-zinc mine tailings and the subsequent migration and transformation characteristics in paddy soil[J]. Chemosphere, 2022, 291: 132792.
[28]	LEI M, LI K, GUO G H, et al. Source-specific health risks apportionment of soil potential toxicity elements combining multiple receptor models with Monte Carlo simulation[J]. Science of the Total Environment, 2022, 817: 152899.
[29]	US Environmental Protection Agency. Regional Screening Levels (RSLs)[EB/OL]. (2023-11-07)[2023-11-10]. https://www.epa.gov/risk/regional-screening-levels-rsls.
[30]	中国环境监测总站. 中国土壤元素背景值[M]. 北京: 中国环境科学出版社, 1990.
[31]	生态环境部,国家市场监督管理总局. 土壤环境质量农用地土壤污染风险管控标准: GB 15618—2018[S]. 北京: 中国标准出版社, 2018.
[32]	范拴喜, 甘卓亭, 李美娟, 等. 土壤重金属污染评价方法进展[J]. 中国农学通报, 2010, 26(17): 310-315.
[33]	宁文婧, 谢先明, 严丽萍. 清远市清城区土壤中重金属的空间分布、来源解析和健康评价: 基于PCA和PMF模型的对比[J]. 地学前缘, 2023, 30(4): 470-484.
[34]	HAN Y M, DU P X, CAO J J, et al. Multivariate analysis of heavy metal contamination in urban dusts of Xi’an, central China[J]. Science of the Total Environment, 2006, 355(1/2/3): 176-186.
[35]	刘楠, 唐莹影, 陈盟, 等. 基于APCS-MLR和PMF的铅锌矿流域土壤重金属来源解析[J]. 中国环境科学, 2023, 43(3): 1267-1276.
[36]	RODRÍGUEZ L, RUIZ E, ALONSO-AZCÁRATE J, et al. Heavy metal distribution and chemical speciation in tailings and soils around a Pb-Zn mine in Spain[J]. Journal of Environmental Management, 2009, 90(2): 1106-1116.
[37]	储彬彬, 罗立强, 王晓芳, 等. 南京栖霞山铅锌矿区铅同位素示踪[J]. 地球学报, 2012, 33(2): 209-215.
[38]	LIU Y B, CUI J, PENG Y, et al. Atmospheric deposition of hazardous elements and its accumulation in both soil and grain of winter wheat in a lead-zinc smelter contaminated area, central China[J]. Science of the Total Environment, 2020, 707: 135789.
[39]	毛景文, 张建东, 郭春丽. 斑岩铜矿-浅成低温热液银铅锌-远接触带热液金矿矿床模型: 一个新的矿床模型: 以德兴地区为例[J]. 地球科学与环境学报, 2010, 32(1): 1-14.
[40]	YANG Q Q, LI Z Y, LU X N, et al. A review of soil heavy metal pollution from industrial and agricultural regions in China: pollution and risk assessment[J]. Science of the Total Environment, 2018, 642: 690-700.
[41]	德兴市自然资源局. 德兴市矿产资源总体规划(2021—2025年)[EB/OL].(2021-10-21)[2023-11-10]. http://www.dxs.gov.cn/dxszrzyj/dx2qovr7/202110/8f0e17e1e2d24f538c3366b472b9557d.shtml.
[42]	戴前进, 冯新斌, 唐桂萍. 土壤汞的地球化学行为及其污染的防治对策[J]. 地质地球化学, 2002, 30(4): 75-79.
[43]	WU Y, WANG S X, STREETS D G, et al. Trends in anthropogenic mercury emissions in China from 1995 to 2003[J]. Environmental Science and Technology, 2006, 40(17): 5312-5318.
[44]	李军, 肖应龙, 李宁, 等. 江西德兴金山金矿富金矿体地质特征研究[J]. 中国金属通报, 2018(9): 36-37, 39.
[45]	李娇, 滕彦国, 吴劲, 等. 基于PMF模型及地统计法的乐安河中上游地区土壤重金属来源解析[J]. 环境科学研究, 2019, 32(6): 984-992.
[46]	HU J J, LIN B J, YUAN M Y, et al. Trace metal pollution and ecological risk assessment in agricultural soil in Dexing Pb/Zn mining area, China[J]. Environmental Geochemistry and Health, 2019, 41(2): 967-980.
[47]	NI S Q, LIU G N, ZHAO Y Y, et al. Distribution and source apportionment of heavy metals in soil around Dexingcopper mine in Jiangxi Province, China[J]. Sustainability, 2023, 15(2): 1143.
[48]	CAI L M, WANG Q S, LUO J, et al. Heavy metal contamination and health risk assessment for children near a large Cu-smelter in central China[J]. Science of the Total Environment, 2019, 650: 725-733.