毕永顺, 朱勇兵, 刘祖文, 赵三平, 张言, 聂果, 郇正来, 田帅, 左华伟. 基于APCS-MLR受体模型的弹药销毁场土壤重金属源解析[J]. 环境化学. doi: 10.7524/j.issn.0254-6108.2023011703
BI Yongshun, ZHU Yongbing, LIU Zuwen, ZHAO Sanping, ZHANG Yan, NIE Guo, HUAN Zhenglai, TIAN Shuai, ZUO Huawei. Analysis of heavy metal sources in soil of ammunition destruction site based on APCS-MLR receptor model[J]. Environmental Chemistry. doi: 10.7524/j.issn.0254-6108.2023011703
Fund Project:
the National Natural Science Foundation of China (52160019)and National Key Research and Development Program of China(2018YFC1801101).
为了掌握弹药销毁场重金属污染状况与来源,以山西某典型弹药销毁场为例,对该销毁场39个表层土壤重金属(Cr、Ni、Cu、Zn、As、Cd、Sb、Pb)的污染状况、分布特征与污染来源进行评价与分析. 结果表明,弹壳堆放区表层土壤重金属Cr、Ni、Cu、Zn、As、Cd、Sb、Pb的平均含量分别为45.57、23.43、325.54、265.43、9.53、0.42、304.17、13174.29 mg·kg
−1
,其余区域表层土壤重金属Cr、Ni、Cu、Zn、As、Cd、Sb、Pb的平均含量分别为102.09、26.75、1137.18、3007.13、7.71、0.95、70.65、2894.97 mg·kg
−1
,均高于山西省背景值. 污染指数评价结果表明,Pb、Zn、Cu、Sb和Cd的累积程度较高. 研究区土壤重金属生态危害指数为2653.35,达到极高生态风险水平. 绝对主成分得分-多元线性回归模型(APCS-MLR)表明,Ni、Cd、Zn、Cr和Cu的来源主要为混合源,贡献率为72.94%,Pb和Sb的主要来源是销毁源,贡献率为53.99%,自然源对As贡献率最大,为44.63%.
弹药销毁场
潜在生态风险
APCS-MLR受体模型
Abstract:
In order to grasp the pollution status and sources of heavy metals in ammunition destruction sites, the pollution status, distribution characteristics and pollution sources of 39 surface soil heavy metals (Cr, Ni, Cu, Zn, As, Cd, Sb, Pb) in this destruction site were evaluated and analyzed, taking a typical ammunition destruction site in Shanxi as an example. The results showed that the average contents of the surface soil heavy metals Cr, Ni, Cu, Zn, As, Cd, Sb and Pb in the shell dumping area were 45.57, 23.43, 325.54, 265.43, 9.53, 0.42, 304.17, 13174.29 mg·kg
−1
, respectively, while the average contents of the surface soil heavy metals Cr, Ni, Cu, Zn, As, Cd, Sb and Pb in the rest of the area were 45.57, 23.43, 325.54, 265.43, 9.53, 0.42, 304.17, 13174.29 mg·kg
−1
, respectively, As, Cd, Sb and Pb were 102.09, 26.75, 1137.18, 3007.13, 7.71, 0.95, 70.65 , 2894.97 mg·kg
−1
respectively, which were all higher than the background values in Shanxi Province. The results of the pollution index evaluation showed that the accumulation of Pb, Zn, Cu, Sb and Cd was high. The ecological hazard index for soil heavy metals in the study area was 2653.35, reaching a very high ecological risk level. The absolute principal component score-multiple linear regression model (APCS-MLR) showed that the sources of Ni, Cd, Zn, Cr and Cu were mainly mixed sources with a contribution of 72.94%, the main sources of Pb and Sb were destruction sources with a contribution of 53.99%, and natural sources contributed the most to As with a contribution of 44.63%.
Key words:
ammunition destruction site
heavy metals
pollution characteristics
potential ecological risks
APCS-MLR receptor model
单个重金属潜在生态风险指数
Potential ecological risk index of individual heavy metals
潜在生态风险指数
Potential ecological risk index
风险等级
Risk level
单个重金属潜在生态风险指数
Potential ecological risk index of individual heavy metals
潜在生态风险指数
Potential ecological risk index
风险等级
Risk level
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E-mail:[email protected];
1. 江西理工大学赣州市流域污染模拟与控制重点实验室,赣州,341000
2. 国民核生化灾害防护国家重点实验室,北京,102205
3. 南昌工程学院水利与生态工程学院,南昌,330099
收稿日期:
2023-01-17
录用日期:
2023-05-12
网络出版日期:
2024-06-27
基金项目:
国家自然科学基金 ( 52160019 )和国家重点研发计划(2018YFC1801101)资助.
APCS-MLR受体模型
摘要:
为了掌握弹药销毁场重金属污染状况与来源,以山西某典型弹药销毁场为例,对该销毁场39个表层土壤重金属(Cr、Ni、Cu、Zn、As、Cd、Sb、Pb)的污染状况、分布特征与污染来源进行评价与分析. 结果表明,弹壳堆放区表层土壤重金属Cr、Ni、Cu、Zn、As、Cd、Sb、Pb的平均含量分别为45.57、23.43、325.54、265.43、9.53、0.42、304.17、13174.29 mg·kg
−1
,其余区域表层土壤重金属Cr、Ni、Cu、Zn、As、Cd、Sb、Pb的平均含量分别为102.09、26.75、1137.18、3007.13、7.71、0.95、70.65、2894.97 mg·kg
−1
,均高于山西省背景值. 污染指数评价结果表明,Pb、Zn、Cu、Sb和Cd的累积程度较高. 研究区土壤重金属生态危害指数为2653.35,达到极高生态风险水平. 绝对主成分得分-多元线性回归模型(APCS-MLR)表明,Ni、Cd、Zn、Cr和Cu的来源主要为混合源,贡献率为72.94%,Pb和Sb的主要来源是销毁源,贡献率为53.99%,自然源对As贡献率最大,为44.63%.
Corresponding author:
LIU Zuwen,
[email protected]
;
1. Ganzhou key laboratory of Basin Pollution Simulation and Control Jiangxi University of Science and Technology, Ganzhou , 341000, China
2. National Key Laboratory of Muclear Biological and Chemical Disaster Protection, Beijing, 102205, China
3. School of Hydraulic and Ecological Engineering,Nanchang Institute of Technology, Nanchang , 330099, China
Received Date:
2023-01-17
Accepted Date:
2023-05-12
Available Online:
2024-06-27
Fund Project:
the National Natural Science Foundation of China (52160019)and National Key Research and Development Program of China(2018YFC1801101).
APCS-MLR receptor model
Abstract:
In order to grasp the pollution status and sources of heavy metals in ammunition destruction sites, the pollution status, distribution characteristics and pollution sources of 39 surface soil heavy metals (Cr, Ni, Cu, Zn, As, Cd, Sb, Pb) in this destruction site were evaluated and analyzed, taking a typical ammunition destruction site in Shanxi as an example. The results showed that the average contents of the surface soil heavy metals Cr, Ni, Cu, Zn, As, Cd, Sb and Pb in the shell dumping area were 45.57, 23.43, 325.54, 265.43, 9.53, 0.42, 304.17, 13174.29 mg·kg
−1
, respectively, while the average contents of the surface soil heavy metals Cr, Ni, Cu, Zn, As, Cd, Sb and Pb in the rest of the area were 45.57, 23.43, 325.54, 265.43, 9.53, 0.42, 304.17, 13174.29 mg·kg
−1
, respectively, As, Cd, Sb and Pb were 102.09, 26.75, 1137.18, 3007.13, 7.71, 0.95, 70.65 , 2894.97 mg·kg
−1
respectively, which were all higher than the background values in Shanxi Province. The results of the pollution index evaluation showed that the accumulation of Pb, Zn, Cu, Sb and Cd was high. The ecological hazard index for soil heavy metals in the study area was 2653.35, reaching a very high ecological risk level. The absolute principal component score-multiple linear regression model (APCS-MLR) showed that the sources of Ni, Cd, Zn, Cr and Cu were mainly mixed sources with a contribution of 72.94%, the main sources of Pb and Sb were destruction sources with a contribution of 53.99%, and natural sources contributed the most to As with a contribution of 44.63%.
在社会经济快速发展以及城市化进程不断加快的背景下,污染场地已经成为全球范围内都要面临的一个全新环境问题
[
1
]
. 由于一些人类活动导致的场地重金属污染,会对土壤环境造成严重污染,破坏生态环境,同时也会通过暴露及食物链对人类健康造成一定影响. 目前国内外对污染场地的重金属监测、风险评估和来源识别研究主要集中在矿区
[
2
−
5
]
、冶炼厂
[
6
−
9
]
、工业区
[
10
−
14
]
等. 随着军事场地土壤重金属污染方面研究的增加
[
15
]
,军事场地的土壤重金属污染问题也受到了国内外学者的广泛关注,主要以靶场、训练场等为主,如Christou等
[
16
]
发现,某靶场土壤中的Pb浓度范围为791 mg·kg
−1
至7265 mg·kg
−1
,比对照背景样本高几十甚至几百倍;Johnsen等
[
17
]
在挪威某射击场土壤中发现,Pb和Cu含量高达3700 mg·kg
−1
和1654 mg·kg
−1
;王亮等
[
18
]
对西藏某军事训练场土壤重金属污染的研究发现,As和Cu的污染源于靶场人为炮弹射击;王诗雨等
[
19
]
对吉林某试验场重金属分布特征、潜在生态风险和来源进行了分析,判断Zn、Pb和Cd主要与试验活动相关的污染源有关;刘玉通等
[
20
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对几种军事场地的重金属的监测发现,留在土壤里的弹药残余物等都能不断地释放出重金属,造成重金属污染在土壤里长期存在;李烨玲、Bai等
[
23
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24
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也分别对中国5个靶场重金属污染水平进行了探究. 而我国对弹药销毁场重金属污染的报道较少. 报废弹药销毁处置是部队及兵工厂的经常性工作,其处置方式主要有分解拆卸、倒空、焚烧以及炸毁等
[
25
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,弹药各零部件中重金属成分种类繁多,长期销毁作业会导致场地受到严重的重金属污染
[
26
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27
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.
根据《建设用地土壤污染状况调查技术导则》(HJ 25.1-2019)中的要求,并结合地形特征和工艺环节等因素,选择了可能污染较重的地块进行采样点位的布设. 在可能存在重度污染的销毁中心(研究区南面)采集了32个土壤样品,编号依次为S1—S32,采样点分布如
图1
所示,研究区北面为弹壳堆放区,也可能受到重金属物污染,在其附近采集了土壤样品7个,编号依次为S33—S39,研究区中部为工房建筑,其余区域已做路面硬化处理,不具备样品采集条件. 所有样品采样深度均为0—20 cm,采用手持GPS进行采样点定位,另外在远离研究区的农田处采集了背景样品3个,用于对照分析. 每个采样点采用五点取样法,去除杂物后采集1.0 kg,混匀后带回实验室. 土壤样品经过自然风干后,挑出石块、植物根系,用玛瑙研磨之后,过2 mm尼龙筛,放入密封袋后待测.
土壤pH测定采用水土比2.5:1(
V/M
)浸提后,用pH计测定;有机质(OM)采用重铬酸钾外加热法测定;采用乙酸铵浸提法测定阳离子交换量(CEC). 使用激光粒度仪(Analysette 22,Fritsch)对土壤粒径进行分析,粒径测量范围为0.01—2000 μm,样品均进行3次检测. 样品通过酸溶法消解后,使用电感耦合等离子体质谱仪(ICP-MS)测定了Cr、Ni、Cu、Zn、As、Cd、Sb和Pb这8种重金属的含量,其检出限分别为2、1、0.6、1、0.4、0.09、0.08、2 mg·kg
−1
. 每批试样设2个空白样,2个平行双样,空白样结果远小于检出限,平行样结果的相对偏差低于10%. 以标准物质GBW07405/GSS-5为质量控制标准,回收率为85%—110%.
研究区土壤pH的范围为7.38—9.81,均值为8.5,呈碱性,与吉林某销毁场研究一致
[
26
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,而背景点的pH均值为7.90,研究区pH的升高可能是焚烧造成的,燃烧后土壤pH会随着有机酸变性、有机质氧化、阳离子释放和碱性灰分进入土壤剖面等机制而升高
[
37
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. 有机质含量为0.59%—4.38%,天然有机质会在销毁区频繁的高温灼烧和物理扰动下分解,留在土壤中的有机质可能来源于有机炸药
[
27
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. 销毁区土壤为砂质土壤,土壤质地在高温下可能发生改变,当燃烧期间土壤表面温度超过250 °C,细粘土颗粒聚集形成沙子,高温也可能导致最上层土层的颗粒增加
[
37
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. 背景点阳离子交换量均值为25.29 mg·kg
−1
,研究区阳离子交换量范围为5.20—40.29 mg·kg
−1
,均值为16.78 mg·kg
−1
,阳离子交换量的降低可能与土壤质地有关,连续的燃烧活动会因含沙量的增加而降低土壤CEC
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37
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.
对土壤样品中重金属元素含量的测定结果如
表3
所示. 弹壳堆放区表层土壤8项重金属元素Cr、Ni、Cu、Zn、As、Cd、Sb、Pb的平均含量分别为45.57、23.43、325.54、265.43、9.53、0.42、304.17、13174.29 mg·kg
−1
,其余区域表层土壤8项重金属元素Cr、Ni、Cu、Zn、As、Cd、Sb、Pb的平均含量分别为102.09、26.75、1137.18、3007.13、7.71、0.95、70.65、2894.97 mg·kg
−1
,前者As、Sb、Pb的平均含量高于后者. 重金属超标率大小顺序为重金属超标率大小顺序为:Zn(79.5%)>Pb(71.8%)>Cu(48.7%)>Sb(35.9%)>Cd(25.6%)>Cr(7.7%)>Ni(2.6%)>As(0),各元素的平均含量显著高于背景区及山西省背景值,且重金属Cr、Ni、Cu、Zn、As、Cd、Sb、Pb含量的平均值是相应筛选值的0.37、0.14、9.92、8.38、0.32、1.42、3.22、27.88倍,说明销毁活动导致研究区土壤中重金属含量明显上升.
Pb是大多数样本中的主要重金属污染物,其次是Zn和Cu. Cd的浓度相对较低,平均浓度约为1 mgkg
−1
或更低,可能是由于它的浓度水平普遍较低. Pb、Cu、Zn浓度的最大值比其他重金属高2—4个数量级,其他重金属的浓度偏低,孟欢等
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27
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在某弹药销毁场的研究中也发现销毁作业使土壤中Pb、Cu、Zn含量升高. 变异系数(CV)代表土壤中重金属分布的均匀程度,CV越大,表明受人类活动干扰越大
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19
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. 一般认为,CV<0.10为弱变异,0.1<CV<1为中等程度变异,CV>1为强变异
[
18
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. 研究区土壤重金属元素的变异系数大小顺序为Zn>Cu>Cd>Pb>Sb>Ni>Cr>1>As>0.1,除As为中等变异外,其余重金属均表现出强变异,表明受到外界因素影响较大. Pb、Cu、Zn这3种浓度较高的重金属具有较大的异质性,其最低浓度范围和最高浓度范围相差3个数量级. 另外,Sb和Cr元素部分被测样品的浓度较高,导致整体平均水平显著升高. Ni和Cd个别样品浓度较大,导致了其高变异系数,反映了销毁场地内表层土壤中重金属的不均匀分布.
如
图2
,土壤重金属单项污染指数大小依次为Pb>Cu>Zn>Sb>Cd>Cr>As>Ni,其中Pb、Cu、Zn为重度污染水平,Sb为中度污染水平,Cd、Cr、As、Ni无污染;综合污染指数大小依次为Pb>Zn>Cu>Sb>Cd>Cr>Ni>As,其中Pb、Zn、Cu、Sb、Cd为重度污染水平,Cr为轻微污染水平,Ni为预警,As为清洁;可以看出尽管单项污染指数表明Zn、Sb、Cd仅为中度、轻度或轻微污染水平,但是在考虑整个区域综合污染指数的情况下,Zn、Sb、Cd达到了重度污染水平. 地累积指数均值结果大小依次为Pb>Sb>Cu>Zn>Cd>Cr>As>Ni,其中Pb为严重污染,Sb为偏重度污染,Cu、Zn为重度污染,Cd为偏重度污染,Cr、As、Ni为清洁. 综合几种重金属污染评价结果,Pb、Zn、Cu、Sb、Cd的污染较重,Cr、As、Ni的污染较轻.
研究区各重金属潜在生态风险Ei大小依次为Pb>Sb>Cu>Cd>Zn>As>Ni>Cr(
图3
),Cr、Ni、As、Zn重金属污染风险指数Ei<40,均表现为轻微生态危害风险级别;其余重金属中除Cd为强生态风险级别外,均表现为极强生态风险级别,这与重金属的污染指数评价结果基本一致. Zn的轻微生态风险级别可能与其较低的毒性系数有关,而Cd的强生态风险级别可能是因为Cd具有较高的毒性系数
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39
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. 值得注意的是,Pb的污染风险指数为1569.53,是极强生态风险等级上限的9.8倍,土壤中Pb的升高可被视为最重要的健康危害
[
24
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. 重金属潜在生态风险RI为2653.35,是极强风险等级上限的4.42倍. 综合考虑重金属含量、污染指数和潜在生态风险,重金属的污染尤为严重,对周边生态环境安全和人类健康存在巨大的隐患. 因弹药销毁而产生的重金属不仅会对周边居民健康产生不良影响,还会对研究区销毁工作人员的健康构成威胁
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,应特别重视重金属对健康的危害,并适时制定应对策略,采取切实有效的保护措施,例如,考虑弹药销毁场地的选址,开展销毁工艺优化等工作.
由因子分析结果可知,因子1解释了整体的42.39%,在Zn、Ni、Cd、Cr和Cu上有较大载荷,且载荷依次减小. 在每个因子上具有较大载荷的元素,载荷系数都大于0.6. 由相关性可知,重金属Zn、Ni、Cd、Cr和Cu两两之间呈极显著相关性,有研究表明,铜锌合金用来增加弹壳的硬度
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,钢芯弹药的燃烧会产生大量Cu和Zn
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. 而在迫击炮、大炮、火箭、瞄准设备和炮弹外壳中也使用了Cu,弹壳和子弹头夹套中高含量的Cu会导致土壤受到严重的Cu污染
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. 军事装备的涂料中含有Cd
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,Ni、Cr会在弹药的制造中以合金的形式加入
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,这5种重金属变异系数较大,易受弹药拆解、销毁等生产作业中产生的废气、废渣等人为因素的影响,有研究表明,Cu、Zn、Cd、Cr、Ni等是军事场地常见的重金属污染物
[
15
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,且这些重金属的累积地点位于焚烧区的主导风向上,会通过大气沉降、地表径流、固废堆弃等方式在土壤中形成富集. 另外,有研究指出,另外,有研究指出肥料、杀虫剂等农产品中Cd、Zn、Cu等重金属含量较高
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,机械设备加工、交通运输等也会产生Cd和Cu等重金属
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,重金属会通过这些途径进入土壤. 以上表明因子1是人为活动(包括焚烧、农业、工业及交通运输等)综合影响. 因子2解释了整体的26.61%,在Pb和Sb上有极高正荷载(0.99和0.98),Pb和Sb呈极显著相关(
P
<0.01). 考虑到Pb和Sb累积处附近区域实际销毁大量枪弹底火,而底火中含有Pb和Sb的化合物
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,通常Pb和Sb会以相对较高的浓度作为共同污染物存在,故因子2可视为销毁活动人为因素. 因子3解释了整体的13.47%,在As上有较大载荷,研究区As的污染程度和CV较小,受销毁和其他活动影响较小,可以归结为土壤母质及风化累积的结果
[
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,因此因子3为自然源.
由PCA和APCS-MLR受体模型分析得到3个主要污染源. 如
图4
,研究区重金属Ni、Cd、Zn、Cr和Cu的来源主要为焚烧、农业、工业及交通运输混合源,其贡献率分别为78.04%、62.84%和53.25%、43.21%、40.86%;Pb和Sb的主要来源是焚烧销毁源,其贡献率分别为72.94%、53.99%,另外还有7.93%和18.55%来自混合源,因为Pb为典型的工业源重金属
[
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,汽车轮胎的磨损以及汽车尾气中也会产生Pb
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,在交通运输方面Pb常被作为机动车污染源的指示性元素
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,且Pb是弹头核心的主要组成成分,Sb是起爆药的主要成分
[
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,与几种混合源相一致;对于As,自然源对其贡献率最大,为44.63%,其次是40.99%的其他源,有13.47%来自混合源,据研究表明,As可作合金添加剂生产铅制弹丸,是铅合金霰弹枪弹药的成分
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,采矿和其他很多工业活动都会释放大量As
[
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,工业燃煤产生的As最终会以大气沉降的方式进入土壤. 研究区重金属的来源是许多因素共同作用的结果,所以自然源对Cr贡献占比也较高,达到19.49%,而其他源对Zn、Cu、Cd和Cr的贡献也较大,占比分别为41.60%、39.24%、29.36%和27.50%,特别是Cu元素,其他源与混合源的占比几乎相同,这也可能是导致Cu变异性特别高的原因
[
36
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.
Figure . Evaluation results of soil heavy metal single factor index, Nemerow comprehensive pollution index and ground accumulation index
Figure . Box diagram of potential ecological risk of heavy metals
Figure . Contribution rate of soil heavy metal pollution sources
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