健康危险度的评价.ppt

,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,我国大气、水体、土壤、室内空气污染及重金属暴露等危害随社会经济的快速发展趋于复合化，造成严重的环境健康问题。,环境污染损害健康的事件频发，已经影响到我国社会的和谐稳定和发展。,理清环境因素与健康效应的关系进而控制和减缓健康问题成为了我国公共卫生领域的挑战。,国家环境与健康行动计划,（,2007-2015,）,完善环境与健康工作的法律、管理和科技支撑，控制有害环境因素及其健康影响，减少环境相关性疾病发生，维护公众健康，促进国家“十一五”规划纲要中提出的约束性指标和联合国千年发展目标的实现，保障经济社会持续协调发展。,建立健全环境与健康监测、调查和风险评估制度,逐步建立健全环境与健康管理制度。开展重点区域、流域、行业环境与健康调查，建立覆盖污染源监测、环境质量监测、人群暴露监测和健康效应监测的环境与健康综合监测网络及风险评估体系。,危险度评价的目的和意义,危险度评价的管理及应用,一、环境污染物的危险度评价,第四节 环境有害因素的预防与控制,危险度评价的组成,第七节 健康危险度评价,有助于对环境中有毒物质进行有效的管理，其结果可为制定环境卫生标准、管理法规、进行卫生监督、采取防治对策和措施、保护环境及人群健康等提供科学依据,1.,概念,危险度评价,（,risk assessment,）,对暴露于某一特定环境条件下，该环境有毒、有害物质或因素可能引起的健康效应及其危害程度进行定性和定量的评价，并预测环境有害物质对暴露人群可能产生的有害效应的概率,。,2.,意义,某化学物对健康危害的可能性（定性危险度评价阶段）,若肯定该物质对健康产生危害，则进一步估计对健康危害的程度（定量危险度评价阶段）,一、危险度评价的组成,1.,危害鉴定,它是健康危险度评价的首要步骤，属于定性评价阶段。,2.,暴露评价,暴露人群的特征包括人群的年龄、性别、职业、易感性等。,暴露剂量分为,外暴露剂量,和,内暴露剂量,暴露评价就是要确定暴露水平（剂量）和暴露人群的特征。,3.,剂量反应关系的评定,它是环境化学物暴露与健康不良效应之间定量评价，,是健康危险度评价的核心。,1,）有阈化学物的剂量反应关系曲线通常为非线性的,S,形曲线。,2,）无阈化学物的剂量反应关系评价需借助数学模型来实现动物试验结果外推至人类。,4.,危险度特征分析,它是根据上述三个阶段所得的定性、定量评价结果，对该化学物在环境中存在时，所致的健康危险度进行综合评价。,对有阈化学物，可计算,1,）人群终生超额危险度,;,2),人群年超额危险度；,3,）人群年超额病例数。,对无阈化学物，可计算：,1,）人群终生患癌超额危险度,;,2),人均患癌年超额危险度；,3,）人群年超额患癌病例数。,二、健康危险度评价的应用,1,预测、预报特定环境因素暴露条件下，暴露人群终生发病或死亡的概率。,2,对各种有害化学物或其他环境因素的危险度进行比较评价，从公共卫生、经济、社会、政治等方面进行论证及各种经济效益、利弊分析，为环境管理决策提供科学依据。,3,有害物质及致癌物环境卫生学标准的研制及提出可接受的浓度，同时研制有关法规、条例，为卫生监督工作提供重要依据。,实例一,广西大厂矿区下游农村土壤重金属污染及儿童健康风险评估,目的：调查广西大厂矿区下游农村土壤中重金属的含量水平，评估其对儿童产生的潜在健康风险。,于,2013,年,7,月，采集大厂矿区下游农村的农田土壤（水田土和蔬菜地土），测定,As,、,Pb,、,Cd,、,Cr,、,Hg,的含量，,并运用美国环保署（,US EPA,）推荐的健康风险评价模型评估该村儿童（,1,6,岁）因土壤经多种途径暴露重金属所引起的非致癌和致癌风险。,与蔬菜地比较，水田土壤中,As,、,Pb,和,Hg,的含量均较高，差异有统计学意义（,P,皮肤接触,呼吸吸入，各重金属的非致癌和致癌日均摄入量依次为,PbAsCrCd,该村土壤中重金属对儿童所致健康危害的年总风险值为,2.1710-6/,年，在,US EPA,推荐的可接受风险水平内，但已存在一定的健康风险。,环境健康风险评估方法在风险管理中的应用,以改水为例,Change of water sources reduces health risks from heavy metals via ingestion of water,soil,and rice in a riverine area,South China,实例,研究地区,Fig.1.,Map of the locations of the three sampling communities in Guangxi Zhuang Autonomous Region,China.,Fig.2,Graphic abstract,Drinking water,Paddy soil,Rice,Water sources change,Ingestion,Human exposure to heavy metals,Change of water sources reduced non-cancer and cancer risks,from ingestion of soil and rice,Risk assessment,Table 1,Heavy metal levels in drinking water(g L,-1,),paddy soils(mg kg,-1,),and rice samples(mg kg,-1,on fresh weight basis)in each studied community.,改水与未改水地区相比：,水田土壤重金属浓度：,As(46.266.8%),；,Pb(65.782.6%),；,Cd(50.855.0%),；,Hg(50.855.0%),大米中重金属浓度：,Cd(39.181.3%),；,Hg(60.075.0%),采用的健康风险评估模型,考虑,3,种暴露途径：饮水、土壤和大米摄入途径,暴露评估及风险表征,a),日均暴露剂量,(ADD),：,ADD=Cs,IREFED/BWAT,(Cs:,各介质浓度,mg/kg,或,mg/L,；,IR,：每日摄入量,g/day,或,L/day;EF:,暴露频率,day/year,；,ED,：暴露持续时间,years,；,BW,：,体重,kg,；,AT,：平均时间，,days),b),非致癌风险,(HQ):HQ=ADD/RfD,(RfD:,参考剂量,mg/kg/day),c),致癌风险,(Risk):Risk=ADDSF,(SF:,致癌斜率因子,mg/kg/day),Tangjun,Sanhe,Lasha,Drinking,water,Soil,Rice,HI,Drinking,water,Soil,Rice,HI,Drinking,water,Soil,Rice,HI,Adults,As,0.05,1.27,2.55,3.87,0.06,0.68,2.55,3.29,0.06,0.42,3.10,3.58,Pb,0.08,0.48,0.08,0.64,0.01,0.17,0.08,0.25,0.05,0.08,0.09,0.23,Cd,0.01,0.004,3.50,3.51,0.01,0.002,2.13,2.14,0.02,0.002,0.66,0.68,Cr,n.c.,a,0.02,0.07,0.09,n.c.,0.02,0.16,0.18,n.c.,0.02,0.27,0.29,Hg,0.02,0.01,1.09,1.12,0.01,0.01,0.44,0.46,0.06,0.01,0.27,0.34,HI,0.16,1.78,7.29,9.23,0.09,0.88,5.36,6.32,0.19,0.53,4.39,5.12,Children,As,0.07,7.62,2.65,10.34,0.09,4.10,2.65,6.84,0.09,2.53,3.22,5.84,Pb,0.11,2.89,0.08,3.08,0.01,0.99,0.08,1.08,0.07,0.50,0.10,0.67,Cd,0.01,0.03,3.63,3.67,0.01,0.01,2.21,2.23,0.03,0.01,0.68,0.72,Cr,n.c.,0.11,0.08,0.19,n.c.,0.13,0.17,0.30,n.c.,0.13,0.28,0.41,Hg,0.02,0.05,1.14,1.21,0.01,0.03,0.45,0.49,0.08,0.03,0.28,0.39,HI,0.21,10.69,7.58,18.48,0.12,5.27,5.56,10.95,0.27,3.20,4.56,8.03,Table 2,Hazard quotient(HQ)and hazard index(HI)for adults and children in the three sampled communities.,改水地区居民经土壤和大米摄入途径暴露重金属,Cd,和,Hg,的非致癌风险水平低于未改水地区（,P1),。,Tangjun,Sanhe,Lasha,Drinking water,Soil,Rice,Risk,total,c,Drinking water,Soil,Rice,Risk,total,Drinking water,Soil,Rice,Risk,total,Adults,As,1.3E+02,3.0E+03,6.1E+03,9.3E+03,1.5E+02,1.6E+03,6.1E+03,7.9E+03,1.5E+02,1.0E+03,7.4E+03,8.6E+03,Pb,1.3E+01,7.8E+01,1.2E+01,1.0E+02,1.0E+00,2.7E+01,1.2E+01,4.0E+01,8.4E+00,1.4E+01,1.5E+01,3.7E+01,Cd,2.1E+02,3.5E+02,2.8E+05,2.8E+05,2.1E+02,1.6E+02,1.7E+05,1.7E+05,7.9E+02,1.7E+02,5.2E+04,5.3E+04,Cr,n.c.,b,1.5E+02,5.8E+02,7.3E+02,n.c.,1.7E+02,1.3E+03,1.5E+03,n.c.,1.7E+02,2.2E+03,2.4E+03,Risk,total,3.5E+02,3.6E+03,2.9E+05,2.9E+05,3.6E+02,2.0E+03,1.8E+05,1.8E+05,9.5E+02,1.4E+03,6.2E+04,6.4E+04,Children,As,2.1E+01,2.2E+03,7.6E+02,3.0E+03,2.5E+01,1.2E+03,7.6E+02,2.0E+03,2.5E+01,7.3E+02,9.3E+02,1.7E+03,Pb,2.1E+00,5.6E+01,1.5E+00,6.0E+01,1.7E-01,1.9E+01,1.5E+00,2.1E+01,1.4E+00,9.7E+00,1.9E+00,1.3E+01,Cd,3.5E+01,2.5E+02,3.5E+04,3.5E+04,3.5E+01,1.1E+02,2.1E+04,2.1E+04,1.3E+02,1.2E+02,6.5E+03,6.8E+03,Cr,n.c.,1.1E+02,7.3E+01,1.8E+02,n.c.,1.2E+02,1.6E+02,2.8E+02,n.c.,1.2E+02,2.7E+02,3.9E+02,Risk,total,5.8E+01,2.6E+03,3.6E+04,3.8E+04,6.0E+01,1.4E+03,2.2E+04,2.4E+04,1.6E+02,9.8E+02,7.7E+03,8.9E+03,Table 3,Cancer risk of each heavy metal and total cancer risk(Risk,total,)for adults and children in the three sampled communities,a,a,All of values presented in the table have been multiplied by 1.0E+07.,改水地区居民经土壤和大米摄入途径暴露重金属,Cd,的致癌风险显著低于未改水地区,(P0.05),但总致癌风险仍高于,USEPA,推荐的,10,-4,最大可接受风险水平。,实例小结,11,与未改水地区相比，改水地区（已改水,23-24,年）土壤及大米中重金属含量（尤其是,Cd,和,Hg,）显著降低。,改水地区人群经土壤和大米摄入途径暴露相应重金属的非致癌和致癌风险均较未改水地区低，但总风险仍超过,USEPA,推荐的最大可接受水平。,对于土壤的污染治理，除了改水，还应当采取其他一些有效措施（如植物修复，利用生物炭修复等）降低土壤中重金属的含量，从而减少重金属对当地居民的健康危害。,Lie Zhang,#,Zhaoyu Mo,#,Jian Qin,#,Qin Li,Yanhong Wei,Shuyan Ma,Yuxia Xiong,Guiqiang Liang,Li Qing,Zhiming Chen,Xiaobo Yang,Zhiyong Zhang,*,Yunfeng Zou*(,Corresponding Author,),Change of water sources reduces health risks from heavy metals via ingestion of water,soil,and rice in a riverine area,South China,Science of the Total Environment,2015,530:163-170,风险管理过程,环境健康风险评估的结果运用于环境监管与人群防护过程，一方面可以加强对环境质量的严格控制，以减少污染；,另外还可以指导采取各种公共卫生干预措施，包括阻断污染物进入人体的途径，广泛开展环境健康风险防范教育，改变人们对于环境健康风险的认识与态度，促进人群防护行为的增加，建立人群健康风险预警，预防和减少污染对敏感人群的危害。,管理措施的制定应当是在风险评估结果的基础上，综合考虑人口、社会、经济等因素，进行最优决策的过程。,Figure by Jane Ades,Courtesy National Human Genome Research Institute,Thank you,