三峡库区主要城镇饮用水源地水质健康风险评价

对三峡库区受回水影响的42个城镇饮用水源地水质进行调查研究,运用美国环境保护署推荐的健康风险评价模型对水源地水体中化学污染物质的健康风险作了初步评价。结果显示:研究区域致癌物的致癌风险偏高,三江水源地总致癌风险1.22×10~(-6)~7.19×10~(-5) a~(-1),支流水源地总致癌风险1.50×10~(-6)~7.19×10~(-5) a~(-1),地下水水源地总致癌风险3.05×10~(-6)~7.19×10~(-5)a~(-1),3种类型水源人均年致癌风险接近或超过了瑞典环境保护署、荷兰建设和环境署、英国皇家协会及国际放射防护委员会(ICRP)推荐的最大可接受风险水平,水源地类型的致癌风险顺序为地下水支流三江水库;非致癌物的总致癌风险均小于或略超过荷兰建设和环境署推荐的可忽略风险水平(10-8 a-1)。因此,认为12种非致癌物通过饮用水途径引起的风险是可以接受的,其总致癌风险处于Ⅲ级、中风险状态。与全国其他区域相比,15种参评因子所占总致癌风险值比例大致相同。     

兰州市城关区地表灰尘重金属污染健康风险评价

以兰州市城关区为研究区域,对多个人群日常活动场所的地表灰尘进行采集,测定了灰尘中重金属(Cu、Zn、Pb、Cr、Cd)含量,采用美国环境保护署(USEPA)推荐的土壤重金属健康风险评价方法,针对儿童和成人2个群体在3种主要暴露途径下的重金属非致癌与致癌健康风险进行了评估。结果表明:兰州市城关区地表灰尘中重金属含量均高于甘肃省土壤背景值。对于非致癌风险,呈现儿童高于成人,手-口摄食皮肤接触呼吸吸入,CrPbCuCdZn的特征。无论儿童还是成人,手-口摄食是导致暴露风险的主要途径,Cr、Pb是危害人体健康的主要元素。儿童的非致癌总风险为9.69×10-1,远高于成人的1.34×10-1,已接近于健康风险阈值(1.00)。Cr、Cd的致癌风险均低于癌症风险阈值范围(10-6~10-4),说明兰州市城关区灰尘重金属对儿童身体健康构成极大潜在危害,但致癌风险较低。     

新疆准东地区降尘重金属污染分析及健康风险评价

使用单因子污染指数及污染负荷指数计算重金属污染水平,应用美国环境保护署人体暴露风险评价方法对6种降尘重金属(Zn、Cu、Cr、Pb、Hg、As)进行健康风险评价。结果表明:(1)新疆准东地区降尘中6种重金属均值都高于昌吉土壤背景值。(2)健康风险评价表明,手-口摄食途径是儿童和成人致癌及非致癌的最主要暴露途径。As是致癌风险的主要贡献者。对于成人而言,降尘重金属的总非致癌和总致癌风险都在可接受的范围内,但儿童总非致癌风险、总致癌风险分别是成人的7.20、1.34倍,且儿童的总非致癌风险已大于安全阈值。     

浙江省饮用水源有机毒物污染特征及健康风险研究

在对浙江省98个县级以上饮用水源地水体中有机毒物污染进行调查的基础上,运用美国环境保护署(EPA)制定的相关模型对饮用水源地水体中有机毒物污染引起的健康风险进行评价。结果表明,在98个饮用水源地水体中共检出7种有机毒物,分别为微囊藻毒素-LR(MC-LR)、微囊藻毒素-RR(MC-RR)、草甘膦、邻苯二甲酸二异辛酯(DEHP)、邻苯二甲酸二丁酯、多环芳烃、咔唑;各饮用水源地水体中检出的有机毒物引起的健康风险大小依次为多环芳烃DEHP咔唑MC-LR草甘膦邻苯二甲酸二丁酯;存在有机毒物检出的饮用水源地水体的总健康风险约为10-13～10-8a-1,与部分国际机构制定的饮用水源地水质健康风险水平判断标准相比,浙江省饮用水源地水体中有机毒物污染引起的健康风险远低于可接受水平,大部分饮用水源地水体的健康风险甚至达到可忽略水平。     

生活垃圾焚烧厂周边大气汞浓度分布及其健康风险评估

利用大气扩散模型AERMOD对生活垃圾焚烧厂周边大气的汞浓度分布进行模拟,并结合健康风险评估和敏感性分析对周边人群的非致癌风险进行评估。结果表明,汞浓度分布可能受风向影响。设置生活垃圾焚烧厂烟气中汞的排放限值为0.05mg/Nm~3,模拟得出高浓度汞出现在距离污染源1 000~1 500m处的西南和偏南方向,最大质量浓度为110ng/m~3。在呼吸吸入的暴露途径下,0~5岁儿童的非致癌风险约为成年人的3倍。成年男性的非致癌风险略大于成年女性。但均远低于美国环境保护署推荐的风险阈值,对人体健康基本不构成威胁。对儿童而言,呼吸速率对非致癌风险影响最大;对成年人而言,体重对非致癌风险影响最大。     

北京高校校园道路灰尘重金属污染特征及健康风险评价

为了解高校校园道路灰尘重金属污染特征及其可能带来的健康风险,在北京10所高校共采集了50个道路灰尘样品,测定了灰尘中Cr、Ni、Cu、Zn、Cd和Pb的浓度,采用美国环境保护署(USEPA)推荐的健康风险评价模型对高校道路灰尘重金属做了初步的健康风险评价。结果表明,北京10所高校校园道路灰尘中Cr、Ni、Cu、Zn、Cd和Pb的平均质量浓度分别为0.77、85.07、82.41、34.03、54.30、308.31mg/kg,均高于北京土壤重金属背景值。10所高校的重金属平均地累积指数(Igeo)排序为ZnCdCuCrPbNi,其中Zn、Cd和Cu处于中度污染水平,Cr和Pb处于轻度污染水平,Ni处于无污染水平。对于非致癌风险,呈现摄食皮肤接触呼吸吸入的特征,摄食是主要的暴露途径,Cr和Pb是主要的风险元素。对于致癌风险,Cr、Ni、Cd的致癌风险均低于风险阈值。高校校园道路灰尘重金属引起的健康风险处于较低水平。     

海浪河水环境重金属污染健康风险评价

为阐明海浪河地表水体中重金属污染物的分布特征与风险水平,对研究区域内As、Cd、Zn、Cu、Pb、Mn等重金属污染物浓度进行了分析检测,并采用美国环境保护局(USEPA)推荐的健康风险评价模型对水体中重金属引起的健康风险进行了评价。结果表明,各采样点的重金属监测数据中As、Cd、Zn和Cu均达到Ⅱ类水质标准,符合水环境功能区划要求,Pb是海浪河主要超标污染物。海浪河重金属As和Cd的健康风险值远远大于Zn、Cu、Pb和Mn的健康风险值,风险值相差4~5个数量级。致癌物As的健康风险值最大,在S5和S6采样点分别达到了5.81×10-5和9.43×10-5a-1,均高于最大可接受风险水平5.0×10-5a-1。     

聊城市城区河湖水中Hg、As浓度分布特征及健康风险评价

为了解聊城市城区河湖水中Hg、As浓度分布,于2010年12月19日采集、分析了20个表层水样中Hg、As浓度,并采用美国环境保护署推荐的健康风险评价模型对其进行了初步评价.结果表明:城区河湖水中Hg、As的质量浓度分别为0.016～0.366、0.494～23.438 μg/L,各主要河湖水中Hg的平均浓度大小为周公河＞东昌湖＞小运河＞徒骇河；As的平均浓度大小为周公河＞徒骇河＞小运河＞东昌湖；东昌湖Hg浓度超过《地表水环境质量标准》(GB 3838-2002)的Ⅲ类水标准值,超标率为71.4％.各主要河湖水中Hg、As浓度的空间分布差异显著,Hg主要来源于大气沉降和沿岸生活污水的排放,As主要来源于工业废水,两者均受到上游来水的影响.As通过饮水途径产生的健康风险值在10-6～10-4 a-1,是Hg的103～106倍,高于部分机构推荐的最大可接受风险水平(1.0×10-6 a-1).建议有关部门应加强对聊城市城区河湖水中Hg、As的监测和环境风险管理.     

危险废物事故排放的河流水环境健康风险评价

分析了基于水体中污染物迁移转化方程的水质预测模型,并借鉴美国环保局推荐使用的健康风险评价模型,建立了一种危险废物事故排放时水环境对人体健康风险的评价方法。以电镀污泥为例验证了该方法的有效性。结果显示:该方法需要参数少且计算简单;电镀污泥中目标污染物(Cr、Cu、Ni、Zn)所引起的河流水环境非致癌风险(1.67)超过了美国标准中的可接受风险水平1.00,不可接受;致癌风险(0.88E-11)则小于美国标准中的可接受风险水平1.00E-06,风险不明显。     

郑州市环境空气中挥发性卤代烃污染特征与健康风险评价

用苏玛罐采样、气相色谱/质谱法分析,研究郑州市环境空气中挥发性卤代烃(VHCs)的污染特征并对其健康风险进行评价。结果显示,郑州市环境空气中共定性检出43种VHCs,其中卤代烷烃28种,卤代烯烃9种,卤代芳香烃6种,卤代烷烃、卤代烯烃、卤代芳香烃的年均质量浓度分别为67.40、34.70、20.30μg/m~3,郑州市各功能区环境空气中VHCs化合物种类稍有差异,背景点VHCs浓度与其他功能区并无显著差异,说明VHCs污染呈现区域性特征;垂直方向上,卤代烷烃浓度随高度呈先降后升趋势,卤代烯烃和卤代芳香烃浓度随高度呈先升后降趋势。健康风险评价结果显示,VHCs单体化合物对人体的非致癌风险均在安全范围内,而总风险超出了安全范围,氯乙烯、三氯乙烯、四氯化碳、氯仿、1,2-二溴乙烷、1,2-二氯乙烷和1,1,2-三氯乙烷的致癌风险超出美国环境保护署规定的可接受值;致癌风险合计为5.32×10~(-4),说明长期暴露于环境空气中对人群健康具有一定危害。     

Optimization of Height of Release of Air Pollutants

A number of key projects in the Environmental Protection Agency (EPA) particulate R&;D program having applicability to industry are presented. For electrostatic precipitators (ESP) there is presented the result of work on large diameter discharge electrodes which provide a decrease in penetration of up to a factor of 4 when compared to conventional small diameter electrodes. Also discussed is the multistage ESP which provides a collection efficiency that would require a collecting plate area 4 or 5 times larger with conventional ESP technology. The E-SOX technology makes use of the multistage concept to free up space in the ESP for SO₂ removals of up to 90%. Electrostatically augmented fabric filtration provides a reduction in pressure drop of about 5 0% as compared to conventional fabric filtration. Wind tunnel modeling of windbreaks for material storage piles indicates a potential for providing engineering design data that would allow significant emission reduction caused by wind erosion     

Investigation of the characteristics of the reflectivity of clouds

This paper investigates some of the reflectivity characteristics that clouds (when modelled as solid bodies) must exhibit to be compatible with observations that the reflecting surface of a cloud (i) appears almost equally bright across its face, (ii) is brightest when the cloud is opposite to the Sun but decreases in brightness as the cloud moves to other positions and (iii) increases in brightness with increasing optical thickness of the cloud in the observer's line of sight. These observations, respectively, are shown to imply that the peak value of the bidirectional total reflectivity from a cloud surface (i) increases in inverse proportion to the cosine of the angle between the Sun and the normal to the cloud surface, as the incident angle increases, (ii) appears to be directed back in the direction of the incident radiation, and (iii) increases as optical thickness of the cloud in the observer's line of sight increases. The results could have application in many fields (e.g. modelling diffuse radiance distributions for cloudy skies).     

次氯酸钠发生器的研制

介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠     

实验室质量管理体系内部审核的策划

在实施ISO／IEC 17025：1999标准《检测和校准实验室能力的通用要求》过程中，通过实验室质量管理体系内部审核的实践与系统分析，识别出内部审核策划阶段的关键环节，提出审核范围确定、审核计划和抽样方案制订的质量控制要求，为有序高效地实施内部审核提供了技术方法。     

An application of the theory of kinematics of mixing to the study of tropospheric dispersion

The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing.     

Estimation of uncertainty of sampling for analysis of pesticide residues

Abstract

A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits.     

扬中生态环境建设的思考与实践

结合扬中生态环境的基本情况和存在的不足，进行了具体分析，对扬中未来生态建设的发展方向提出了建议及实施措施。     

Comparison of methods for evaluation of activity of photocatalytic films

Objective

This work aims to investigate the correlation between the photocatalytic activity determined by methylene blue bleaching (DIN 52980), stearic acid degradation, and degradation of acetone in gas phase.

Method

The photocatalytic TiO₂ coatings included in this investigation ranged from thin commercially available coatings (Activ^TM and BioClean^TM) and ready to use suspensions (Nano-X PK1245) to lab-produced PVD and sol?Cgel coatings. XRD analysis of the photocatalytic coatings showed that all the coatings consisted of nanocrystalline anatase, although the thickness and porosity varied considerably.

Results

The study showed that the reproducibility of the activity measurements was good. However, more importantly, the investigation showed that there is a good correlation between the activities determined by the different methods even though the characteristics of the photocatalytic coatings and the organic probe molecules varied considerably.

Conclusion

The overall findings of this work suggest that there is a good correlation between the investigated methods. These results are promising for the future work concerning standardization of methods for determination of the activity of photocatalytic films.     

Impact of overexploitation of shellfish: northeastern coast of India

India has a very extensive coastline of about 7515 km, rich in diverse living resources. These resources continue to deteriorate with rampant harvesting or are altered for other uses such as aquaculture and fisheries. The present paper deals with degrading coastal habitats in northeastern India, and projects the intensity of the stress arising from the collection of tiger prawn seeds (Penaeus monodon) for aquacultural farms and molluskan shells for poultry feed and edible lime. Indiscriminate exploitation of these resources leads to a heavy reduction of the species concerned and other associated marine communities. The magnitude of such destruction has been quantified. The impacts of biodiversity loss and their after-effects on the ecobalance of this coastal system have become a matter of great concern to ecologists to maintain security and sustainability. The authors propose a public awareness program on themes relating to the importance of biodiversity for human livelihoods.