常州市浅层地下水重金属污染对城区、城郊居民健康风险评价

采用美国EPA推荐的风险评价模型,同时考虑研究区人群基本情况和生活习惯等,进行推荐模型的参数优化,建立适合研究区人群的风险评价方法,并对城区、城郊不同暴露途径下地下水污染进行健康风险评价.结果表明,常州城区饮水暴露途径与皮肤暴露途径致癌风险男性分别为2.79×10-3和2.81×10-5,女性分别为1.87×10-3和2.45×10-5;非致癌风险男性分别为3.48×10-6和3.79×10-5,女性分别为2.27×10-6和3.01×10-5.城郊饮水暴露途径与皮肤暴露途径致癌风险男性分别为1.26×10-3和1.32×10-5,女性分别为9.77×10-4和1.18×10-5;非致癌风险男性分别为4.07×10-6和3.43×10-5,女性分别为2.14×10-6和9.71×10-6,风险水平均处于可接受范围内.敏感性分析表明饮水暴露途径下各因子的敏感性在-19.8%—20.1%之间,皮肤暴露途径下各因子的敏感性在-14.8%—16.1%之间,对研究区人群暴露参数进行调查实测,降低了评价结果的不确定性.研究浅层地下水的健康风险评价,对合理开发该区域地下水资源具有重要参考价值.     

贵阳市西郊水厂所供管网末梢水重金属污染物季节性特征及潜在健康风险评价

以贵阳市西郊水厂2014年3月和7月所供管网末梢水中10种重金属污染物检测数据为基础,进行了季节性特征分析,并采用美国环保局(USEPA)推荐的健康风险评价模型进行了潜在健康风险评价。结果表明,贵阳市西郊水厂所供管网末梢水中10种重金属的浓度均符合国家饮用水卫生标准;重金属污染物的浓度随季节呈现出不同的特征,汞、锌、硒、钼和钡5种重金属的平均浓度呈现枯水期高于丰水期的特征,而铅、铜、锰和镍4种重金属正好相反,砷浓度的季节性特征不显著;成年人的年平均致癌风险显著大于儿童,但两者年平均非致癌风险接近;儿童和成年人2类人群经口暴露途径的健康风险值均大于皮肤暴露,其中致癌风险分别在2.49×10-6~9.16×10-6和3.26×10-8~9.59×10-8之间,非致癌风险在2.29×10-8~3.20×10-8和1.85×10-10~4.14×10-10之间,且致癌风险均大于非致癌风险。贵阳市西郊水厂所供管网末梢水中10种重金属污染物致癌风险和非致癌风险均未超过最大可接受水平,未对该供水区居民的健康造成威胁。     

拉萨市垃圾填埋场地下水水质的居民健康风险评价

对拉萨市垃圾填埋场地区地下水6个监测井中的Cr~(6+)、As、Cd、Pb、NO~-_3-N、F~-、Cl~-指标采用美国环保局USEPA推荐的健康风险评价模型,按照不同人群进行健康风险评价.评价结果表明,通过暴露剂量计算,在饮水途径和皮肤接触途径下非致癌物暴露剂量一般高于致癌物暴露剂量;饮水途径暴露剂量高于皮肤接触途径下的暴露剂量.致癌污染物在饮水途径下风险值大于皮肤接触途径下的风险值,其中饮水途径下风险贡献为Cr~(6+)AsCd,Cr~(6+)风险值超过USEPA的最大可接受水平1×10~(-4);在皮肤接触途径下贡献为Cr~(6+)AsCd,Cr~(6+)的风险值超过瑞典环保局、荷兰建设环保局、英国皇家协会和IAEA最大可接受风险水平;非致癌风险的污染物贡献最大的是Cl~-,其通过饮水暴露途径在成人中风险值高于瑞典环保局(1×10~(-6))、荷兰建设环保局(1×10~(-6))、英国皇家协会(1×10~(-6))和IAEA(5×10~(-7))最大可接受水平.因此,致癌物中Cr~(6+)成为主要的致癌物,人们在饮水中要将其去除,起到预防癌症和减少患癌的几率.     

岩溶槽谷区土壤多环芳烃健康风险评价

以重庆老龙洞岩溶槽谷为例,利用BaP毒性当量浓度(BaP_(eq))和终生癌症风险增量模型对儿童和成人暴露于土壤PAHs的健康风险进行评价.研究结果表明,土壤中BaP_(eq)∑_(16)PAHs为87.5±156.6 ng·g~(-1),7种致癌性PAHs占了97.8%;BaP_(eq)∑_(10)PAHs平均值为32.9±37.4 ng·g~(-1),33.3%的采样点的BaP_(eq)超过了荷兰土壤环境质量标准目标参考值(33.0 ng·g~(-1)),表明土壤PAHs存在潜在风险;儿童和成人的终生癌症风险(ILCR)分别为1.17×10~(-7)—7.11×10~(-6),1.24×10~(-7)—7.52×10~(-6),平均值为8.8×10~(-7)和9.3×10~(-7),总体在可接受的风险范围内,但有部分存在潜在风险;DaA和BaP产生的致癌风险占到总风险的35.2%和30.4%,是最主要的贡献组成;不同暴露途径对人群的致癌风险水平为:皮肤接触经口摄入呼吸吸入.经口摄入和皮肤接触对总致癌风险的贡献几乎为100%,高出呼吸吸入10~2—10~6倍,是土壤PAHs致癌风险的主要暴露途径.     

环境中有机磷农药污染状况、来源及风险评价

环境中农药的污染残留问题备受社会关注,尤其是食品安全这一方面.作为世界上有机磷农药(OPPs)生产和使用的大国,国内环境中OPPs的残留赋存问题尤其受到重视.残留在环境中水体、土壤、生物体的OPPs可能经口、皮肤接触、呼吸等暴露途径进入人体对人体健康造成风险.了解OPPs在国内主要江河湖泊、土壤、生物体中的残留赋存情况并进行风险评价至关重要.本文对比总结了中国环境中水体、土壤、生物体中主要OPPs的含量范围、检出率及其分布特征,并利用美国RBCA健康风险评价模型对其进行健康风险评价和RQ商值法进行水生生态风险评价.结果显示,中国地表水体含量最高的5种OPPs分别是敌敌畏、乐果、对硫磷、马拉硫磷、甲基对硫磷,浓度变化范围ND—30180 ng·L~(-1),北方水体的OPPs污染状况水平要高于南方水体.OPPs风险评价结果显示,地表水、土壤、蔬菜中OPPs的非致癌风险系数(HQ)分别为7.25×10~(-5)—6.93×10~(-1)、9.56×10~(-7)—5.30×10~(-2)、1.08×10~(-2)—7.01×10~(-1),都还未超过1的安全标准,对人体健康不会产生明显的不良影响.地表水中敌敌畏的致癌风险系数(R)范围为2.86×10~(-8)—6.25×10~(-6)在10~(-5)—10~(-6)安全范围内.对比地表水、土壤、蔬菜的HQ值,蔬菜中残留的单体OPPs对人体的健康风险大于地表水和土壤,水生生态风险评价结果中OPPs对糠虾和水蚤RQ值1,处于高风险.     

内蒙古某地区饮用水砷含量与人体暴露及致癌风险分析

砷的季节变化对暴露评估及健康风险评价的准确性具有重要影响。选择内蒙古某饮水型砷中毒病区为研究区,评估不同季节砷的直接摄入量、间接摄入量和皮肤接触吸收量,并评价砷的致癌健康风险。结果表明:(1)研究区男性和女性居民砷的摄入量分别为1.80和1.89μg·kg~(-1)·d~(-1),明显高于对照区的0.08和0.08μg·kg~(-1)·d~(-1);研究区男性和女性居民砷的皮肤接触吸收量分别为8.89×10~(-4)和1.10×10~(-3)μg·kg~(-1)·d~(-1),明显高于对照区的4.18×10~(-5)和4.93×10~(-5)μg·kg~(-1)·d~(-1)。(2)研究区居民的砷摄入量占摄入及皮肤接触途径暴露量之和的99.93%以上,夏季及冬季砷暴露量占全年砷暴露量的89.04%以上。(3)研究区男性和女性居民砷的致癌健康风险分别为3.75×10~(-5)和3.67×10~(-5)a~(-1)。由研究结果可知,摄入是饮水型砷暴露的主要途径;夏季砷的暴露量最高,冬季次之;研究区居民摄入及皮肤接触途径的砷致癌健康风险均超过可接受风险水平(10~(-6)a~(-1))。     

南昌市道路尘PM2.5中重金属分布特征及健康风险评价

为了解南昌市道路尘PM_(2.5)中重金属元素的分布特征和健康风险,利用颗粒物再悬浮采样器采集了道路尘中的PM_(2.5)样品,用电感耦合等离子体质谱仪和原子荧光光谱仪测定了样品中11种重金属元素的含量.结果表明,道路尘PM_(2.5)中Mn、Zn、Cr、Cu、Pb、V、As、Ni、Co、Cd和Hg的平均含量分别为1014、208.17、106.47、102.40、62.12、39.59、28.93、24.07、7.86、0.58、0.53 mg·kg~(-1),除V和Co外均大于南昌市土壤元素背景值,整体上次干道和支路的金属含量会高于主干道重金属的含量,比国内外其他城市相对要低.地累积指数结果显示,Cd、Hg、Cu、Mn和Zn处于偏中度污染,As和Pb属于轻度污染,其余元素处于无污染水平.日均暴露剂量表明,Mn在儿童的非致癌日均暴露剂量最高(摄食:2.83×10~(-3) mg·(kg·d)~(-1),呼吸吸入:2.50×10~(-7) mg·(kg·d)~(-1),皮肤接触:6.87×10~(-6) mg·(kg·d)~(-1)),经口摄食是人体暴露的主要途径,Cr的终身暴露剂量最高(儿童:8.63×10~(-9) mg·(kg·d)~(-1),成年男性:9.12×10~(-9) mg·(kg·d)~(-1),成年女性:8.12×10~(-9) mg·(kg·d)~(-1)).11种重金属对儿童、成年女性和成年男性的非致癌风险值之和分别为0.58,0.19和0.17,小于可接受风险值1.0,As、Cr、Mn是主要贡献元素;5种致癌元素(Cr、As、Co、Ni和Cd)经呼吸途径对人体的总致癌风险值均小于可接受水平10~(-6),成年男性(4.29×10~(-7))略高于儿童(4.06×10~(-7))和成年女性(3.82×10~(-7)),Cr和As是主要贡献元素.     

西南某矿区家庭灰尘中重金属的暴露及其健康风险评价

家庭灰尘是人群居住场所的重要环境介质,人群可通过吸入、摄食及皮肤接触等途径摄入灰尘中的污染物,对健康造成一定的损伤。为探索我国西南某矿区周边村庄室内重金属的污染对人群健康的潜在风险,采用2014年3月对我国西南某矿区周边村庄室内灰尘中重金属污染水平调查的数据,结合美国EPA健康风险评价模型对人群健康风险进行分析。结果表明:人群非致癌风险和致癌风险暴露剂量均表现为儿童>成人男性>成人女性,呈现手-口摄食途径>皮肤接触途径>吸入途径,其中儿童、成人男性和成人女性手-口摄食暴露途径占总暴露剂量的98.16%、55.61%和51.5%;儿童以Pb、Cr的暴露为主,成人以Cr的暴露为主;家庭灰尘中单种重金属元素和多途径叠加的非致癌风险在8.81E-03~1.24E-02之间,均小于1,其中儿童以Pb的非致癌风险为主,经手-口摄食暴露占总风险的40%;致癌风险在4.19E-05~3.35E-04之间;A、B、C村儿童的致癌风险均高于US EPA所推荐的可接受水平10-4,其暴露剂量和健康风险均为成人男性和成人女性的5~6倍,且以Cr通过手-口摄食暴露产生的风险最大,占总风险的93%左右。     

厦门大气PM_(2.5)中元素特征及重金属健康风险评价

通过在厦门市鼓浪屿、洪文和湖里进行冬夏两季的PM_(2.5)环境样品采集,利用能量色散X射线荧光分析仪分析了其中16种元素(Al、Si、Ca、Ti、V、Cr、Mn、Fe、Ni、Cu、Zn、Cd、Sn、Sb、Ba和Pb)的浓度,对其时空变化特征和重金属的健康风险评价进行了研究.结果表明,Al、Si、Ca、Ti和Fe等地壳元素浓度较高,其浓度值冬高夏低.受区域功能和排放影响,所测元素浓度湖里点最高(2.12μg·m-3),鼓浪屿最低(1.15μg·m-3).富集因子计算结果表明,地壳元素中Ca富集因子为43,与建材类物质输入有关.受工业排放、机动车和船舶排放影响,重金属元素富集因子普遍高于100,特别是Cu、Zn、Cd、Sn和Sb的富集因子高达103—104.PMF源解析结果表明,厦门PM_(2.5)中元素来自于地壳源、机动车源、工业源、船舶源和燃煤源.重金属元素的暴露剂量、非致癌风险和致癌风险等计算结果显示,Zn暴露剂量最大(儿童:1.23×10-7mg·(kg·d)-1,成人:0.53×10-7mg·(kg·d)-1),Mn非致癌暴露风险最高(儿童:1.20×10-3,成人:5.18×10-4),Cr致癌暴露风险最高(儿童:1.80×10-7,成人:7.76×10-8).相应的暴露风险为冬高夏低,湖里点最高,鼓浪屿最低.总体来看,重金属的非致癌暴露风险和致癌暴露风险均远小于判断标准,表明厦门PM_(2.5)中重金属元素不存在明显的非致癌和致癌健康风险.     

区域环境中多环芳烃的皮肤接触暴露水平

通过实例介绍污染物-皮肤接触暴露的量化方法.选择了多环芳烃污染较严重的天津市,计算了该地区人群通过2种主要皮肤接触途径(皮肤-降尘接触和皮肤-洗浴水接触)对区域环境中16种PAH化合物(PAH16)的皮肤接触暴露与健康风险.儿童、青少年和成人三个亚群对PAH16的日均皮肤接触暴露量分别为3.41×10-2、2.68×10-2、1.95×10-2μg.kg-.1d-1.终生加权暴露量为2.20×10-2μg.kg-1.d-1.不确定性分析的结果表明,至少50%人群对PAH16暴露量在2.00×10-2—4.00×10-2μ.gkg-.1d-1范围内,暴露量极高和极低的人都很少.在16种化合物中,皮肤接触暴露优势化合物是Phe,F la,Pyr,Bap和Baa.皮肤途径终生加权暴露对总暴露量的贡献很低(1.06%),换算为BaP等效浓度(BaPeq)后则增加到6.00%.人群由于PAH16皮肤接触暴露所导致的平均致癌风险为8.1×10-7a-1,并未超出最大可接受风险1×10-5a-1.     

口服纳米银对大鼠的生物有效性及其体内分布的研究

由于独特的抗菌特性,纳米银(AgNP)在诸多领域得到广泛应用,但是其生物有效性、动物组织分布及排出尚不清楚。将聚乙烯吡咯烷酮包被的AgNP溶液按照10 mg·kg~(-1)给雌性SD大鼠灌胃,采用ICP-MS检测SD大鼠组织、粪便及尿液中总银浓度。结果表明,AgNP通过小肠吸收后,可以通过血液循环快速分布在肝、肾、脾、肺、脑等靶器官。灌胃后1 h,大鼠各组织中总银浓度达到最大值(肝、肾、脾、肺、脑中银浓度分别为(0.29±0.13)mg·kg~(-1)、(0.23±0.04)mg·kg~(-1)、(0.17±0.05)mg·kg~(-1)、(0.11±0.01)mg·kg~(-1)、(0.06±0.02)mg·kg~(-1)),之后银浓度随时间而降低,直至和对照组无显著性差异。在灌胃途径下,AgNP对SD大鼠的有效性为8.5%,且73%的AgNP是通过粪便的途径排出体外。     

口服纳米银对大鼠的生物有效性及其体内分布的研究

由于独特的抗菌特性，纳米银(AgNP)在诸多领域得到广泛应用，但是其生物有效性、动物组织分布及排出尚不清楚。将聚乙烯吡咯烷酮包被的AgNP溶液按照10 mg kg^-1给雌性SD大鼠灌胃，采用ICP-MS检测SD大鼠组织、粪便及尿液中总银浓度。实验结果表明，AgNP通过小肠吸收后，可以通过血液循环快速分布在肝、肾、脾、肺、脑等靶器官。灌胃后1 h，大鼠各组织中总银浓度达到最大值(肝、肾、脾、肺、脑中银浓度分别为0.29 ± 0.13 mg kg^-1、0.23 ± 0.04 mg kg^-1、0.17 ± 0.05 mg kg^-1、0.11 ± 0.01 mg kg^-1、0.06 ±0.02 mg kg^-1)，之后银浓度随时间降低直至和对照组无显著性差异。在灌胃途径下，AgNP对SD大鼠的有效性为8.5%，且73%的AgNP是通过粪便的途径排出体外。     

Is using nanosilver mattresses/pillows safe? A review of potential health implications of silver nanoparticles on human health

Human exposure to engineered nanoparticles has become inevitable in today’s extensive commercial use and large-scale production of engineered nanoparticles. Even though several studies have characterised the exposure to nanomaterials during wakeful state (related to occupational exposures and exposures from commercially available particles), very few studies on human exposure during sleep exist. As the study of exposure to all possible nanomaterials during sleep is extensive, this study focuses on exposure to specifically silver nanoparticles which are present in beddings and mattresses. The reasoning behind the use of silver nanoparticles in bedding and related materials, possible routes of entry to various population groups in several sleep positions, exposure characterisation and toxicity potential of such silver nanoparticles are reviewed in this study. The toxicity potential of silver nanoparticles in vivo tests with relation to mammals and in vitro tests on human cells has been tabulated to understand the risks associated during oral, dermal and inhalation exposure to silver nanoparticles. The exposure to humans with regard to dermal absorption and oral intake has been summarised. Although potential inhalation exposure to silver nanoparticles is increasing, only a few studies address the possible toxic effect of inhaled silver particles. Determination of exposure to silver nanoparticles in beddings is a topic that has been less researched, and this review aims to provide background information for future research and help establish a comprehensive risk assessment during sleep in the times of increasing usage of nanoparticles in our daily activities. Despite the current limitations of our understanding, risk assessments must utilise the available data and apply extrapolation procedures in the face of uncertainty, in order to address the needs of regulatory programs. This would enable safe use of the antimicrobial properties of silver nanoparticles without negatively impacting human health. Until then, it would be better to adopt a conservative approach on the usage of silver nanoparticles in daily used commercial items.

     

再生水处理过程中轮状病毒的变化规律及风险评价（Change of Rotavirus in Sewage Treatment Processes and Associated Health Risk Assessment）

为探讨污水处理厂不同处理工艺段对轮状病毒(Rotavirus)的去除效果及再生水回用中轮状病毒对暴露人群的健康风险水平,于2006年11月至2007年10月连续对北京市某污水厂各工艺段出水的轮状病毒进行了分析,并应用Beta-Possion模型对回用再生水中轮状病毒对暴露人群的健康风险水平进行了评价.结果表明,36个实测水样中,轮状病毒检测结果为阳性的样品13个,占总样品数的36.1%.阳性样品主要分布在2006年11月、12月和2007年1月、2月、4月、8月和10月所采集的样品中,各月份阳性样品所占比例分别依次为100%、100%、100%、33.3%、66.7%、33.3%和100%.二级处理工艺对轮状病毒的去除率为2.68-lg,二级处理出水经过混凝沉淀和砂滤两种深度处理后得到再生水,深度处理工艺平均去除率为3.01-lg.二沉出水回用对不同职业暴露人群的年均感染概率风险值范围为0.35×10-2~10.36×10-2,再生水回用不同职业暴露人群年平均感染风险概率值范围为0.23×10-2~6.82×10-2,二沉出水、再生水回用导致的道路喷洒职业工人轮状病毒暴露感染风险值最大,分别达到了39.65×10-2和36.82×10-2,存在着一定的健康风险.     

Spatial health risk assessment and hierarchical risk management for mercury in soils from a typical contaminated site,China

Due to rapid urbanization and the implementation of ecological civilization construction in China, many industrial factories have been closed or relocated. Therefore, numbers of contaminated sites were generated with contaminated soils which may pose a risk to receptors living nearby. This study presented a spatial health risk assessment and hierarchical risk management policy making for mercury (Hg) in soils from a typical contaminated site in the Hunan Province, central China. Compared with the second class value (0.3 mg/kg) of the Chinese Environmental Quality Standard for Soils, the mean concentrations of Hg in the three soil depths exceeded the second class value. The non-carcinogenic risk of Hg probably posed adverse health effects in 41, 30 and 36 % of the surface soil, the moderate soil and subsoil, respectively, under a sensitive land scenario. The non-carcinogenic risk temporarily posed no adverse health effects in most areas under an insensitive land scenario except for the area around sampling site S29. Spatially, the central, southwest and northeast parts of the contaminated land under a sensitive land scenario should be regarded as the priority regions. For non-carcinogenic effects, the exposure pathways that resulted in the higher levels of exposure risk were ingestion and inhalation of vapors, followed by dermal contact and inhalation of particles. A risk-based integrated risk management policy including the hierarchical risk control values for different soil depths and the calculated remediation earthwork was proposed with consideration of the cost-benefit effect for the related decision-makers.     

Aggregation and dissolution of silver nanoparticles in a laboratory-based freshwater microcosm under simulated environmental conditions

Silver nanoparticles (NP) are used in several applications, including their use as antimicrobial agents in textiles, personal care, and other domestic products. As such, there is a high potential for the release of silver nanoparticles (AgNP) in the aquatic environment. In aquatic ecosystems, nanomaterials are affected by abiotic factors, such as temperature, that alter their chemistry and influence their fate in the environment. Preliminary studies indicate that NP tend to form aggregates which are potentially more recalcitrant than unaggregated NP. These and other fate processes are largely dependent on both the characteristics of the NP and that of the environment. In this study, lab experiments were conducted to investigate the physicochemical properties and temperature solubility of AgNP (<100 nm) that may potentially influence the fate and behavior of AgNP in the aqueous environment. Results indicated that, under these tested conditions, AgNP may be transformed in size and thereby affect fate, bioavailability, and toxicity. In this study, a novel method was used to determine whether AgNP would form agglomerates, or behave as isolated particles, or dissolve when in aqueous media and under different environmental conditions. The new aspects evaluated in this study demonstrated that AgNP are transformed in both size and state under variable environmental conditions.     

Study of sorptive properties of trap systems for selective enrichment of volatile organic compounds from tobacco smoke samples

There is a dearth of data on the consumer product concentrations of iron, lead, and nickel for accurate comparison to be made. The levels of these elements were determined in 85 samples of six different classes of personal care products commonly used in Nigeria using atomic absorption spectrophotometry. The results of the analysis showed that the range of the mean concentrations of Fe was 0.485–1.108 ppm, Pb ND–0.163 ppm, and Ni ND-0.160 ppm. The analytical data have demonstrated that the selected consumer products are possible sources of iron, lead, and nickel exposure. Users can be exposed to these metals directly through dermal contact or inhalation. The regulations relating to cosmetic products give no limit values for heavy metals in cosmetic products, hence, it was difficult to establish if the values obtained in this study are safe or not. Prolonged use of soaps, creams, and detergent containing these elements may pose threat to human health and the environment. This could be responsible for various skin diseases such as allergic skin, follicular and pigmentary disorders, which are common among the users (exposed groups) of these products in Nigeria. A body of evidence has presented a rare example of systemic allergic dermatitis caused by topical application of a mercury-containing cosmetic to the upper lip of a 32-year-old Turkish patient.     

蔬菜水果中的新烟碱类农药残留量与人群摄食暴露健康风险评价

新烟碱类农药是目前被广泛用于农业中的一类作用独特、高效广谱的内吸性杀虫剂,它们在蔬菜水果中的残留对人体健康构成威胁。本研究目的是查明北京市场上蔬菜水果中不同新烟碱类农药的残留量,并对人群摄食暴露健康风险进行评估。从北京市场上采集49种蔬菜和24种水果,采用Qu ECh ERS–高效液相色谱串联质谱(HPLC-MS/MS)法测定蔬菜水果中9种新烟碱类农药的含量。利用测得数据和中国居民膳食结构调查资料,采用蒙特卡罗模拟方法计算了不同年龄段人群的日均经口摄入暴露量的概率分布,并采用商值法计算了新烟碱类农药的非致癌风险。结果显示新烟碱类农药普遍存在于北京市场上的蔬菜水果中。49种蔬菜样品中检出7种新烟碱类农药,其中吡虫啉、啶虫脒和噻虫嗪检出率均达100%,噻虫胺、烯啶虫胺、噻虫啉和呋虫胺的检出率分别为47%、14%、10%和4%。24种水果样品中检出5种新烟碱类农药,其中吡虫啉和啶虫脒的检出率均达100%,噻虫嗪、噻虫胺和噻虫啉的检出率分别为54%、13%和4%。不同新烟碱类农药在蔬菜水果中的含量范围为0.01 ng·g~(-1)~126 ng·g~(-1),均未超过我国食品安全国家标准或美国联邦管理条例中的限量值。小部分(约3%)人群因摄食蔬菜水果暴露于新烟碱类农药的非致癌风险商值大于0.1。新烟碱类农药在蔬菜水果中普遍存在,对人体健康有潜在的风险。     

Contamination levels and human health risk assessment of toxic heavy metals in street dust in an industrial city in Northwest China

This study investigated the content, distribution, and contamination levels of toxic metals (Cd, Cr, Cu, Pb, and Zn) in street dust in Lanzhou, an industrial city in Northwest China. Meanwhile, the risk these metals posed to the urban ecosystem and human health was also evaluated using the potential ecological risk index and human exposure model. Results showed that concentrations of these metals in the dust are higher than the background value of local soil, with Cu having the highest levels. The districts of Anning and Xigu had the most extreme levels of contamination, while Chengguan and Qilihe districts were lightly contaminated, which can be partly attributed to human activities and traffic densities. In comparison with the concentrations of selected metals in other cities, the concentrations of heavy metals in Lanzhou were generally at moderate or low levels. Heavy metal concentration increased with decreasing dust particle size. The pollution indices of Cr, Cd, Cu, Pb, and Zn were in the range of 0.289–2.09, 0.332–2.15, 1.38–6.21, 0.358–2.59, and 0.560–1.83 with a mean of 1.37, 1.49, 3.18, 1.48, and 0.897, respectively. The geo-accumulation index (I _geo) suggested that Zn in street dust was of geologic origin, while Cd, Cr, Pb, and Cu were significantly impacted by anthropogenic sources. The comprehensive pollution index showed that urban dust poses a high potential ecological risk in Lanzhou. Non-carcinogenic and carcinogenic effects due to exposure to urban street dust were assessed for both children and adults. For non-carcinogenic effects, ingestion appeared to be the main route of exposure to dust particles and thus posed a higher health risk to both children and adults for all metals, followed by dermal contact. Hazard index values for all studied metals were lower than the safe level of 1, and Cr exhibited the highest risk value (0.249) for children, suggesting that the overall risk from exposure to multiple metals in dust is low. The carcinogenic risk for Cd and Cr was all below the acceptable level (< 10⁻⁶).