-
重金属是一类对生态环境系统和人体健康危害性极大的污染物[1]. 随着经济社会的快速发展,由工农业生产等人类活动产生的各类型重金属污染物进入到土壤等不同环境介质当中[2-3]. 土壤是农业生产的基础,赋存在土壤中的重金属污染物,通过根系富集等途径进入到农作物的不同部位,影响作物的生长发育,经不同层级食物链的累积作用最终危害到人体健康[4-6]. 目前粮食安全问题日益凸显,食用受污染的农作物已成为重金属摄入的主要方式[7-8].
农作物重金属污染评价已成为环境科学领域研究的热点问题之一. 受土壤中重金属污染物累积程度、土壤理化特征、不同作物对重金属元素富集能力等因素影响,不同作物或同一作物不同部位中重金属的污染特征和健康风险存在较大差异. 已有学者针对不同农作物对重金属的富集能力强弱、土壤理化特征对重金属富集程度的影响等方面进行了相关研究,如水稻对Pb的富集能力强于小麦[9],而小麦富集Cd的能力强于水稻[10]. Ding和王怡雯发现[11-12],土壤Cd含量、pH值、有机质等对作物吸收Cd具有显著的影响. 孙亚芳对比分析了天津市污灌区和清灌区小麦、水稻子实中重金属的含量,结果表明污水灌溉会增加重金属在植物体内的累积[13]. 小麦是我国第二大作物,受土壤污染影响,部分地区已经出现小麦重金属超标现象,如江苏省某地震带小麦籽粒Pb、Cr、Hg、Ni、As超标率分别为100%、58.97%、33.33%、10.26%、2.56%[14],天津市某污灌区冬小麦籽粒中As、Pb、Hg、Cr、Cd、Se均有不同程度的超标[15]. 已有研究对小麦重金属污染评价大多针对污灌区、矿区周边农田等具有明显污染源的区域,而对一般农业生产区域中的小麦籽粒重金属研究较少.
河南省是我国重要粮食大省和后备资源储粮基地,小麦是该地区主要粮食作物,在人们日常饮食中占有较大比重. 2017年河南省发布的《关于河南省重金属污染防治工作指导意见》中,安阳市龙安区被列入国家重金属污染防控重点区域[16],但针对该区域作物重金属污染研究未有报道. 基于此,本文以安阳市龙安区为研究区域,对该区域小麦籽粒重金属进行系统的污染评价,旨在为粮食作物重金属的风险管控和安全生产提供依据.
小麦籽粒重金属含量特征及人体健康风险评价——以河南省北部某县为例
Characteristics of heavy metal content in wheat grains and human health risk assessment — A county in northern Henan Province
-
摘要: 为评价小麦籽粒重金属含量污染特征及其健康风险,以河南省北部某县为研究区,采集小麦籽粒样品283个,测定样品中As、Pb、Cd、Cr含量,采用污染指数法、健康风险评价等方法分析研究区小麦籽粒中重金属污染程度,揭示空间分布特征,并评价人体健康风险. 结果表明,小麦籽粒中As、Pb、Cd、Cr的平均含量分别为0.063、0.053、0.193、0.177 mg.kg−1,Cd的超标率最高;小麦籽粒中重金属综合污染指数为1.435,达到轻污染程度;空间分级特征结果表明,附近交通和钢铁化工企业等因素是产生高污染的主要原因; As、Cd、Cr对成人和儿童健康风险系数最小值为6.32×10−4,均超出USEPA推荐的最大可接受标准,存在较高的致癌风险.Abstract: In order to evaluate the pollution characteristics and health risk of heavy metals in wheat grain, 283 wheat grain samples were collected from a county in northern Henan Province, and the contents of As, Pb, Cd and Cr in the samples were determined. The pollution degree of heavy metals in wheat grain in the study area was analyzed by pollution index method and health risk assessment, and the spatial distribution characteristics were revealed, and the human health risk was evaluated. The results showed that the average contents of As, Pb, Cd and Cr in wheat grains were 0.063, 0.053, 0.193 and 0.177 mg·kg−1, respectively, and the exceeding rate of Cd was the highest. The comprehensive pollution index of heavy metals in wheat grains was 1.435, reaching the level of light pollution. The spatial classification results show that the factors such as nearby traffic and steel chemical enterprises are the main causes of high pollution. The minimum health risk indexes of As, Cd and Cr for adults and children were 6.32×10−4, which exceeded the maximum acceptable risk range recommended by USEPA, and there was a high carcinogenic risk.
-
Key words:
- wheat grains /
- heavy metals /
- pollution assessment /
- health risk
-
表 1 健康风险模型评价参数
Table 1. Evaluation parameters of health risk mode
表 2 研究区各乡镇小麦污染指数及污染等级占比
Table 2. Wheat pollution index and pollution grade proportion in townships of the study area
区域
Areas样品数
Sample numbers元素
Elements单因子污染指数
Single factor contaminant index不同污染等级占比/%
Proportion of different pollution levels/%最大值 平均值 最小值 无污染 轻度污染 中度污染 重度污染 田村街道 26 As 0.286 0.150 0.010 100 田村街道 26 Pb 0.347 0.235 0.115 100 Cd 6.2 2.935 0.150 11.54 26.92 15.39 46.15 Cr 0.032 0.021 0.016 100 马投涧镇 225 As 1.124 0.133 0.006 99.53 0.47 Pb 1.945 0.279 0.108 97.78 2.22 Cd 8.400 1.976 0.240 21.78 42.67 22.67 12.88 Cr 3.210 0.191 0.011 94.44 4.17 1.39 龙泉镇 4 As 0.262 0.101 0.017 100 Pb 0.66 0.456 0.253 100 Cd 1.4 0.744 0.056 50 50 Cr — — — — 东风乡 28 As 0.156 0.051 0.014 100 Pb 0.575 0.231 0.110 100 Cd 2.200 0.852 0.330 75 21.43 3.57 Cr 0.080 0.048 0.014 100 “—”表示数据缺失. 表 3 小麦摄入途径下重金属摄入量及非致癌风险
Table 3. Heavy metal intake and non-carcinogenic risk under wheat intake pathway
重金属
Heavy metalADD HQ 成人 儿童 成人 儿童 Pb 3.78×10−4 5.86×10−4 1.08×10−1 1.67×10−1 表 4 小麦摄入途径下重金属摄入量及致癌风险
Table 4. Heavy metal intake and carcinogenic risk under wheat intake pathway
人群
PopulationADD RI R As Cd Cr As Cd Cr 成人
Adults4.50×10−4 1.37×10−3 1.26×10−3 6.75×10−4 8.40×10−3 6.32×10−4 9.71×10−3 儿童
Children6.96×10−4 2.13×10−3 1.95×10−3 1.04×10−3 1.30×10−2 9.79×10−4 1.50×10−2 -
[1] BRADL H B. Sources and origins of heavy metals[M]//Heavy Metals in the Environment: Origin, Interaction and Remediation. Amsterdam: Elsevier, 2005. 1-27. [2] 刘剑飞, 胡留杰, 廖敦秀, 等. 食用菌生物修复重金属污染研究进展 [J]. 应用生态学报, 2011, 22(2): 543-548. LIU J F, HU L J, LIAO D X, et al. Bioremediation of heavy metal pollution by edible fungi: A review [J]. Chinese Journal of Applied Ecology, 2011, 22(2): 543-548(in Chinese).
[3] 强承魁, 秦越华, 丁永辉, 等. 徐州地区麦田土壤和小麦籽实重金属污染特征分析 [J]. 生态环境学报, 2016, 25(6): 1032-1038. QIANG C K, QIN Y H, DING Y H, et al. Pollution characteristics of heavy metals in soils and wheat grains in Xuzhou area [J]. Ecology and Environmental Sciences, 2016, 25(6): 1032-1038(in Chinese).
[4] CHEN H Y, TENG Y G, LU S J, et al. Contamination features and health risk of soil heavy metals in China [J]. Science of the Total Environment, 2015, 512/513: 143-153. doi: 10.1016/j.scitotenv.2015.01.025 [5] JOSEPH T, DUBEY B, MCBEAN E A. Human health risk assessment from arsenic exposures in Bangladesh [J]. Science of the Total Environment, 2015, 527/528: 552-560. doi: 10.1016/j.scitotenv.2015.05.053 [6] SEYED A M, REZA S A, FAEZEH H. Heavy mental concentration and availability of different soils in Sabzevar area, NE of Iran [J]. Journal of African Earth Sciences, 2017, 134(10): 106-112. [7] KHAN S, CAO Q, ZHENG Y M, et al. Health risks of heavy metals in contaminated soils and food crops irrigated with wastewater in Beijing, China [J]. Environmental Pollution, 2008, 152(3): 686-692. doi: 10.1016/j.envpol.2007.06.056 [8] ZARCINAS B A, PONGSAKUL P, MCLAUGHLIN M J, et al. Heavy metals in soils and crops in Southeast Asia 2. Thailand [J]. Environmental Geochemistry and Health, 2004, 26(3/4): 359-371. [9] 蔡燕子, 谢湉, 于淑玲, 等. 黄河三角洲农田土壤-作物系统重金属污染风险评估 [J]. 北京师范大学学报(自然科学版), 2018, 54(1): 48-55. CAI Y Z, XIE T, YU S L, et al. Assessment of the heavy metal pollution risks in soil-crop systems of farmlands in the Yellow River Delta [J]. Journal of Beijing Normal University (Natural Science), 2018, 54(1): 48-55(in Chinese).
[10] 范健, 廖启林, 许宏铭, 等. 稻米与小麦吸收土壤重金属的基本特征 [J]. 地质学刊, 2016, 40(4): 701-709. doi: 10.3969/j.issn.1674-3636.2016.04.701 FAN J, LIAO Q L, XU H M, et al. General characteristics of heavy metals absorbed by rice and wheat seeds within topsoil of farmland [J]. Journal of Geology, 2016, 40(4): 701-709(in Chinese). doi: 10.3969/j.issn.1674-3636.2016.04.701
[11] DING C F, ZHANG T L, WANG X X, et al. Prediction model for cadmium transfer from soil to carrot (Daucus carota L.) and its application to derive soil thresholds for food safety [J]. Journal of Agricultural and Food Chemistry, 2013, 61(43): 10273-10282. doi: 10.1021/jf4029859 [12] 王怡雯, 芮玉奎, 李中阳, 等. 冬小麦吸收重金属特征及与影响因素的定量关系 [J]. 环境科学, 2020, 41(3): 1482-1490. WANG Y W, RUI Y K, LI Z Y, et al. Characteristics of heavy metal absorption by winter wheat and its quantitative relationship with influencing factors [J]. Environmental Science, 2020, 41(3): 1482-1490(in Chinese).
[13] 孙亚芳, 王祖伟, 孟伟庆, 等. 天津污灌区小麦和水稻重金属的含量及健康风险评价 [J]. 农业环境科学学报, 2015, 34(4): 679-685. doi: 10.11654/jaes.2015.04.011 SUN Y F, WANG Z W, MENG W Q, et al. Contents and health risk assessment of heavy metals in wheat and rice grown in Tianjin sewage irrigation area, China [J]. Journal of Agro-Environment Science, 2015, 34(4): 679-685(in Chinese). doi: 10.11654/jaes.2015.04.011
[14] 陈京都, 戴其根, 许学宏, 等. 江苏省典型区农田土壤及小麦中重金属含量与评价 [J]. 生态学报, 2012, 32(11): 3487-3496. doi: 10.5846/stxb201105080598 CHEN J D, DAI Q G, XU X H, et al. Heavy metal contents and evaluation of farmland soil and wheat in typical area of Jiangsu Province [J]. Acta Ecologica Sinica, 2012, 32(11): 3487-3496(in Chinese). doi: 10.5846/stxb201105080598
[15] 马传鑫, 汪志荣, 高琼, 等. 天津市典型污灌区冬小麦各生育期的重金属分析 [J]. 环境化学, 2010, 29(1): 44-47. MA C X, WANG Z R, GAO Q, et al. Heavy metal analysis of winter wheat at each stage in typical sewage irrigated area of Tianjin [J]. Environmental Chemistry, 2010, 29(1): 44-47(in Chinese).
[16] 河南省重金属污染防治工作指导意见[Z]. 河南省环境保护厅, 2017. Guidance on Prevention and Control of Heavy Metal Pollution in Henan Province [Z]. Henan Provincial Department of Environmental Protection, 2017.
[17] CAO C, CHEN X P, MA Z B, et al. Greenhouse cultivation mitigates metal-ingestion-associated health risks from vegetables in wastewater-irrigated agroecosystems [J]. Science of the Total Environment, 2016, 560/561: 204-211. doi: 10.1016/j.scitotenv.2016.04.044 [18] 康国华, 张鹏岩, 李颜颜, 等. 黄河下游开封段引黄灌区小麦中重金属污染特征及健康风险评价 [J]. 环境科学, 2018, 39(8): 3917-3926. KANG G H, ZHANG P Y, LI Y Y, et al. Pollution characteristics and health risk assessment of heavy metals in wheat grains cultivated in Kaifeng irrigation area of the Yellow River [J]. Environmental Science, 2018, 39(8): 3917-3926(in Chinese).
[19] 段小丽. 中国人群暴露参数手册概要-儿童卷 [M]. 北京: 中国环境出版社, 2016.1-1107. DUAN X L. Highlights of the Chinese exposure factors handbook 分辑名: 儿童卷 Children[M]. Beijing: China Environmental Press, 2016.1-1107(in Chinese). [20] USEPA. Superfund public health exaluation manual [R]. EPA/540/1-86/060. Washington, DC: Environmental Protection Agency, 986, 1-52. [21] 张江华, 徐友宁, 吴耀国. 小秦岭金矿区小麦和玉米重金属的健康风险评价 [J]. 地质学报, 2019, 93(2): 501-508. doi: 10.3969/j.issn.0001-5717.2019.02.016 ZHANG J H, XU Y N, WU Y G. Health risk assessment of heavy metals in wheat and maize in the Xiaoqinling gold mining Area [J]. Acta Geologica Sinica, 2019, 93(2): 501-508(in Chinese). doi: 10.3969/j.issn.0001-5717.2019.02.016
[22] CASRN 7439-92-1, Lead and compounds (inorganic) [S]. [23] CASRN 7440-43-9, Cadmium [S]. [24] 王世玉, 吴文勇, 刘菲, 等. 典型污灌区土壤与作物中重金属健康风险评估 [J]. 中国环境科学, 2018, 38(4): 1550-1560. doi: 10.3969/j.issn.1000-6923.2018.04.043 WANG S Y, WU W Y, LIU F, et al. Assessment of human health risks of heavy metals in the typical sewage irrigation areas [J]. China Environmental Science, 2018, 38(4): 1550-1560(in Chinese). doi: 10.3969/j.issn.1000-6923.2018.04.043
[25] 杨文晓. 陕西主要麦区小麦籽粒中重金属含量调查及对人体健康的风险评价[D]. 杨凌: 西北农林科技大学, 2019: -82 YANG W X. Inverstigation of heavy metal concentrtaion in wheat grain and human health risk assessment in Shaanxi Province[D]. Yangling: Northwest A & F University, 2019.1-82.
[26] 张青, 段海龙, 廖蕾, 等. 内蒙古河套地区小麦重金属含量与土壤质量的关系研究 [J]. 安全与环境工程, 2010, 17(1): 36-40. doi: 10.3969/j.issn.1671-1556.2010.01.009 ZHANG Q, DUAN H L, LIAO L, et al. Research on the relationship between the heavy metal content of wheat and the quality of soil in Hetao area, Inner Mongolia [J]. Safety and Environmental Engineering, 2010, 17(1): 36-40(in Chinese). doi: 10.3969/j.issn.1671-1556.2010.01.009
[27] 李晓燕, 陈同斌, 谭勇壁, 等. 北京市小麦籽粒的重金属含量及其健康风险分析 [J]. 地理研究, 2008, 27(6): 1340-1346. doi: 10.3321/j.issn:1000-0585.2008.06.013 LI X Y, CHEN T B, TAN Y B, et al. Concentrations and risk of heavy metals in grain of wheat grown in Beijing [J]. Geographical Research, 2008, 27(6): 1340-1346(in Chinese). doi: 10.3321/j.issn:1000-0585.2008.06.013
[28] 朱昊, 吴春发, 陈宜. 苏中地区小麦籽粒重金属含量水平及健康风险 [J]. 环境监测管理与技术, 2017, 29(1): 35-38,56. doi: 10.3969/j.issn.1006-2009.2017.01.008 ZHU H, WU C F, CHEN Y. Concentrations of heavy metals in wheat grains and their potential health risk in the central region of Jiangsu [J]. The Administration and Technique of Environmental Monitoring, 2017, 29(1): 35-38,56(in Chinese). doi: 10.3969/j.issn.1006-2009.2017.01.008
[29] 赵多勇, 魏益民, 魏帅, 等. 区域小麦籽粒重金属分布及暴露评估 [J]. 中国粮油学报, 2016, 31(7): 6-10,18. doi: 10.3969/j.issn.1003-0174.2016.07.002 ZHAO D Y, WEI Y M, WEI S, et al. Spatial distribution of heavy metal in wheat kernal and dietary exposure assessment of local residents in an industrial area [J]. Journal of the Chinese Cereals and Oils Association, 2016, 31(7): 6-10,18(in Chinese). doi: 10.3969/j.issn.1003-0174.2016.07.002
[30] 阳小成, 赵桂丹, 熊曼君, 等. 川西北高原路侧土壤重金属分布特征及污染评价 [J]. 应用与环境生物学报, 2018, 24(2): 239-244. YANG X C, ZHAO G D, XIONG M J, et al. Spatial distribution and risk assessment of soil heavy metal contamination along roadsides of the northwestern Sichuan Plateau, China [J]. Chinese Journal of Applied and Environmental Biology, 2018, 24(2): 239-244(in Chinese).
[31] FÉLIX O I, CSAVINA J, FIELD J, et al. Use of lead isotopes to identify sources of metal and metalloid contaminants in atmospheric aerosol from mining operations [J]. Chemosphere, 2015, 122: 219-226. doi: 10.1016/j.chemosphere.2014.11.057 [32] 王学锋, 姚远鹰. 107国道两侧土壤重金属分布及潜在生态危害研究 [J]. 土壤通报, 2011, 42(1): 174-178. WANG X F, YAO Y Y. Spatial distribution and ecological hazard of heavy metals in roadside soils along the 107th national highway [J]. Chinese Journal of Soil Science, 2011, 42(1): 174-178(in Chinese).
[33] 任福民, 汝宜红, 许兆义, 等. 铁路旅客列车垃圾中重金属元素调查及防治对策的研究 [J]. 中国安全科学学报, 2002, 12(3): 74-78. doi: 10.3969/j.issn.1003-3033.2002.03.019 REN F M, RU Y H, XU Z Y, et al. Investigation on heavy metal content in garbage from passenger trains and study on countermeasures [J]. China Safety Science Journal, 2002, 12(3): 74-78(in Chinese). doi: 10.3969/j.issn.1003-3033.2002.03.019
[34] FILZEK P D B, SPURGEON D J, BROLL G, et al. Pedological characterisation of sites along a transect from a primary cadmium/lead/zinc smelting works [J]. Ecotoxicology, 2004, 13(8): 725-37. doi: 10.1007/s10646-003-4472-6 [35] 王娟娟. 鲁北平原引黄灌区土壤-小麦系统重金属分布特征及污染风险评价[D]. 济南: 山东师范大学, 2019.1-89. WANG J J. Distribution characteristics and pollution risk assessment of heavy metals in soil-wheat system of Yellow River irrigation district in lubei plain[D]. Jinan: Shandong Normal University, 2019.1-89.
[36] 肖冰, 薛培英, 韦亮, 等. 基于田块尺度的农田土壤和小麦籽粒镉砷铅污染特征及健康风险评价 [J]. 环境科学, 2020, 41(6): 2869-2877. XIAO B, XUE P Y, WEI L, et al. Characteristics of cd, as, and Pb in soil and wheat grains and health risk assessment of grain-Cd/as/Pb on the field scale [J]. Environmental Science, 2020, 41(6): 2869-2877(in Chinese).