持久性有机污染物(POPs)的环境问题与研究进展

对持久性有机污染物(persistentorganicpollutants:POPs)的定义、来源和特征进行了介绍。阐述了POPs对环境安全性构成威胁的原因。分析了持久性有机污染物,特别是12类优先控制的"dirtydozen"的环境污染状况,并分析了这些物质在全球大气、水体和土壤中存在的量和来源。这些物质在不同生物体内的浓度存在差异,反映出它们在食物链上的生物累积和放大,也加剧了对环境和人体的毒害作用。总结回顾了有关POPs的相关基础研究,并对将来继续深入研究和对环境监测的指导意义进行了展望。  

国内外二恶英研究初探

总结了国际上近年来环境中二恶英的研究成果及进展概况。主要分挤二恶英的毒性及来源，综合国内外有关二恶英的绝大部分研究成果，并简要提出二恶英的防治措施。  

杭州市环境空气中二噁英类物质检测与分析

为了解二噁英类物质(PCDD/Fs)在环境空气中污染现状及不同季节不同时段浓度、组成和存在形式等的变化情况,于夏、冬两季对杭州西湖区空气中PCDD/Fs进行了采样分析。结果表明,空气中PCDD/Fs毒性当量浓度与国内其他城市(北京、上海、广州)相近,夏、冬两季空气中PCDD/Fs质量浓度和毒性当量浓度分别为4.92 pg/m3、0.34 I-TEQ pg/m3和4.51 pg/m3、0.40 I-TEQ pg/m3,夏季PCDD/Fs毒性当量浓度略低于冬季;在分时段采样检测结果中,晚间空气中PCDD/Fs质量浓度和毒性当量浓度均高于白天空气中的PCDD/Fs浓度;夏季样品中TCDD/Fs、PeCDD/Fs主要以气相的形式存在,HpCDD/Fs、OCDD/F主要以颗粒相的形式存在,冬季样品中PCDD/Fs主要以颗粒相形式存在。  

二(噁)(口英)类污染物排放的农业面源分析

以三种树叶焚烧测定结果为例,分析了植物燃烧过程中产生的二类。研究结果表明,不同植物焚烧排放的二类浓度不同,含氯高时排放二类浓度也较高。二类对生态环境和人类健康有巨大的危害,分析二类污染物的农业面源情况,对于进一步有效控制和降低二类的排放,有重要的现实意义。  

关于火电厂验收存在的问题分析

对火电厂中以煤、天然气、油或焦油、秸秆为原料时验收监测应注意的问题进行了分析和探讨。重点提出了烟气脱硫、Hg、As、氟化物的污染以及多环芳烃、二的产生和以后环评、环评批复及验收监测中应注意的问题。  

深圳市大气中PCDD/Fs污染水平初步研究

目的:了解深圳市大气中二 NFDA2 NFDA1 (PCDD/Fs)的污染水平和分布特征。方法:利用大流量空气采样器分别采集6个采样点的空气样品,每个采样点采集两个平行样品。参照美国环保总局(US EPA Method TO-9A)二 NFDA2 NFDA1 的检测方法,通过高分辨气相色谱-高分辨双聚焦磁式质谱仪(HRGC/HRMS)对大气样品中17种具有毒性当量因子(TEF)的单体进行了定性和定量分析。结果: ∑PCDD/Fs的浓度范围为0.23~11.88pg/m³(平均值为3.84 pg/m³)。毒性当量浓度范围为0.014~0.29 pg I-TEQ/m³(平均值为0.135 pg I-TEQ/m³)。OCDD、HpCDD、HpCDF、OCDF、HxCDF是丰度较大的单体,分别占总浓度的48.21%、15.85%、11.37%、7.40%、6.59%。 PCDDs和PCDFs单体浓度(除OCDF之外)均随氯原子取代个数的增加而增大。2,3,4,7,8- PeCDF对总的毒性当量贡献最大,占总毒性当量浓度的38.87%。六个采样点中有三个地点二 NFDA2 NFDA1 同系物分布显示了"源"的特征,而另外三个地点则显示了"汇"的特征。成人的PCDD/Fs暴露量为0.0023~0.047 pg I-TEQ/kg ·day;儿童PCDD/Fs暴露量为0.0052~0.11 pg I-TEQ/kg ·day。结论:深圳市大气样品中二 NFDA2 NFDA1 浓度低于国内一些城市研究水平,而高于日本、欧美国家的研究水平。  

垃圾焚烧飞灰中二噁英类的研究概况

随着垃圾焚烧技术的推广应用,焚烧产生的污染越来越受关注,本文介绍了二噁英的检测方法、垃圾焚烧飞灰中二噁英的分布、影响因素及飞灰的处置和综合利用技术研究概况。  

新疆二噁英类POPs排放现状调查及分析

在对新疆二噁英类POPs排放调查的基础上，归纳了新疆二噁英类污染物的主要来源和分布情况，分析了新疆二噁英类POPs排放源在环境监管中存在的问题，并提出了相应的建议，对今后新疆二噁英类POPs排放的管理、控制和削减有重要意义。  

Northern Rivers Ecosystem Initiative: Distribution and Effects of Contaminants

In response to a number of recommendations following the Northern Rivers Basin Studies (NRBS) contaminant program, the Northern Rivers Ecosystem Initiative (NREI) focused considerable attention on assessing contaminants from specific sources including pulp mill effluents, atmospheric transport of mercury and the Alberta oil sands operations. NRBS identified a number of major contaminants of concern including polychlorinated biphenyls, dioxins and furans, mercury and various hydrocarbons. Together, the NRBS and the NREI studies have demonstrated major declines in the levels of dioxins and furans over the last decade as pulp and paper mills have changed their process and treatment strategies in response to new Federal regulations. Polychlorinated biphenyls however, continue to be a concern for the region as their levels have not declined in fish and sediments over the course of these studies. Higher levels in sediments downstream of Grande Prairie and Hinton were identified, but the source of these contaminants remains unknown. Chlorinated pesticides were also investigated, and although toxaphene, DDT and other chlorinated organic pesticides were detected in fish tissue, they were present at very low levels. Studies on the oil sands industry in northern Alberta demonstrated limited impacts on the Athabasca River to date, although studies did identify slight to moderate impacts of natural oil seeps on fish and benthic communities in tributary streams. NREI studies also identified endocrine active compounds in the three pulp and paper mill effluents tested, but endocrine disruptive effects in wild fish were minimal. Municipal sewage effluents also contain endocrine active compounds and it is recommended that monitoring continue around these point sources.  

Concentrations of PM2.5-associated OC, EC, and PCDD/Fs measured during the 2003 wildfire season in Missoula, Montana

Throughout August and September, 2003, wildfires burned in close proximity to Missoula, Montana, with smoke emanating from the fires impacting the valley for much of the summer. This presented the perfect opportunity to measure the levels of polychlorinated dibenzodioxins and dibenzofurans (PCDD/F) comprising ambient forest fire smoke particles impacting the Missoula Valley. An air sampler at the Montana Department of Environmental Quality's (DEQ) compliance site in Missoula measured hourly averages of PM₁₀ throughout the fire season. Three collocated PM_2.5 cyclones collected 24-h smoke samples using quartz filters and Polyurethane Foam (PUF) sorbent cartridges. From the quartz filters, concentrations of Organic and Elemental Carbon (OC/EC) were measured, while PCDD/F were measured from one set of a filter (particle phase) and PUF (vapor phase) aggregate of samples in an attempt to also investigate the different phases of PCDD/F in forest fire smoke impaired communities.Hourly PM₁₀ concentrations peaked at 302.9 μg m⁻³ on August 15. The highest OC concentration (115.6 μg m⁻³) was measured between August 21–22, and the highest EC concentration of 10.5 μg m⁻³ was measured August 20–21. Measurable concentrations of PM_2.5 associated PCDD/Fs were not detected from a representative aggregate sample, with the exception of small amounts of 1,2,3,4,6,7,8-heptachlorodibenzodioxin and octachlorodibenzodioxin. PM_2.5 samples collected during the smoke events were composed of approximately 65% OC. However, the OC fraction of the particles collected in the smoke impaired Missoula valley was not composed of significant amounts of PCDD/F.