Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in sediments from Hong Kong

Concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in 14 sediment samples collected from four sites in the Mai Po Marshes Nature Reserve (within a RAMSAR Site) and from another six sites in Victoria Harbour and along the Hong Kong coastline. Elevated levels of PCDDs, and particularly OCDD, were detectable in all samples collected from the Mai Po Marshes and five of the six sites. In contrast to PCDDs, PCDFs were mainly found in sediment samples collected from industrial areas (Kwun Tong and To Kwa Wan) in Victoria Harbour. PCDD/F levels and congener profiles in the samples from the Mai Po Marshes Nature Reserve in particular show strong similarities to those reported in studies which have attributed similar elevated PCDD concentrations to nonanthropogenic PCDD sources.     

PM10 and heavy metal measurements in an industrial area of southern Italy

Atmospheric particulate concentrations and heavy metal content are measured from March to July 2001 at an industrial site located in a rural zone of the southern Italy. PM₁₀ samples are collected by a low-volume sampler and each sample is analysed by AAS techniques for its content of Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. We measure also temperature, atmospheric pressure and relative humidity, and we collect anemometric data. The study purpose is the investigation of pollutant levels in an industrial area located in a rather unpolluted region and the characterization of the correlation structure among particulate concentrations, heavy metal content and local meteorological parameters. Data analysis is carried out by means of univariate and multivariate statistical methods. In the investigated period, the average value of PM₁₀ daily concentrations (24 μg Nm^− 3) does not exceed the national standard of 40 μg Nm^− 3 and only nine values are higher than the European daily limit value of 50 μg Nm^− 3. Particularly, the occurrence of two anomalous values (183 μg Nm^− 3 in 3 March and 94 μg Nm^− 3 in 22 June) seems to be related to no-local events as confirmed both by in situ data measured in the AQM network of Potenza city (about 10 km far from the study area) and by remote measurements performed in the same days. Regarding the heavy metal levels, we observe high levels of Cr (34 ng Nm^− 3), Ni (85 ng Nm^− 3) and Zn (214 ng Nm^− 3) in agreement with the local industrial source pattern. The multivariate analysis, carried out using meteorological parameters as exogenous variables, allow to evaluate the role of the different variables as driving factors of the correlation structure among the metals.     

北京市朝阳区沙子营垃圾污染物在潜水含水层中迁移规律的现场模拟实验

选择北京平原区水文地质、环境地质等方面都比较典型的沙子营垃圾堆放场,建立了其水文地质模型。在充分收集资料、分析得出部分计算所需参数后,采用现场弥散实验、勘查取样测试等方法,求得了该含水层的弥散系数等参数;用二维非稳定流溶质运移方程对污染物在此含水层中的迁移扩散规律、速度和污染范围等进行了模拟计算;采用现场钻探、取样测试分析等方法,评价了该含水层的实际污染状况。实验模拟计算和现场调查结果表明:污染物在潜水含水层中的运移规律遵循二维非稳定流场中的溶质运移方程,污染物在潜水含水层中的运移速度约为86.25m/a,迁移扩散主要发生在地下水流向上,侧向扩散宽度极小,是地下水流向上的1/17。     

南宁市大气能见度变化特征及影响因子分析

对2000至2006年的南宁市能见度资料进行统计分析。分析表明,南宁市近7a能见度年均值在13～17km之间,总体呈下降趋势。一年之中,能见度最小值主要出现在1至3月,最大值出现在6至7月,汛期能见度明显好于非汛期。一日之中,能见度的日变化为：08时〈02时〈20时〈14时。能见度与气象因子的相关分析表明,能见度与温度、风速成正比,与压强、降水、湿度成反比。与污染物的相关分析表明,能见度与PM10浓度的相关性较强,达到-0.58。     

Persistent organic pollutants and stable isotopes in biopsy samples (2004/2006) from Southern Resident killer whales

“Southern Resident” killer whales include three “pods” (J, K and L) that reside primarily in Puget Sound/Georgia Basin during the spring, summer and fall. This population was listed as “endangered” in the US and Canada following a 20% decline between 1996 and 2001. The current study, using blubber/epidermis biopsy samples, contributes contemporary information about potential factors (i.e., levels of pollutants or changes in diet) that could adversely affect Southern Residents. Carbon and nitrogen stable isotopes indicated J- and L-pod consumed prey from similar trophic levels in 2004/2006 and also showed no evidence for a large shift in the trophic level of prey consumed by L-pod between 1996 and 2004/2006. ∑PCBs decreased for Southern Residents biopsied in 2004/2006 compared to 1993–1995. Surprisingly, however, a three-year-old male whale (J39) had the highest concentrations of ∑PBDEs, ∑HCHs and HCB. POP ratio differences between J- and L-pod suggested that they occupy different ranges in winter.     

东亚季风区近地面大气气溶胶中OCPs和PCBs纬度分布：以7Be为参照系

连续一年在北京、青岛、广州以每周3d的时间尺度同步采集近地面大气中气溶胶中7Be的测定数据以及在春、秋季节变换时期我国5个不同纬度城市大气气溶胶中7Be和典型持久性有机污染物（有机氯农药和多氯联苯1的同步观测数据,并对文献上发表的我国其他城市近地面大气中气溶胶中’Be年平均值数据进行了分析。通过对以上数据资料的总结和分析,观察到在东亚季风区近地表大气气溶胶中7Be浓度的年平均值呈现正态分布模式,并且在中纬度北纬40°N附近达到极大值。大气气溶胶中7Be在春、秋季节变换时期我国不同纬度城市的瞬时纬度分布仍呈现正态分布模式,但以30°N为最大值。在秋季大气颗粒相中HCHs和PCBs浓度最大值出现在30°N。气相中PCB-28所占百分比随纬度增高而增大,而颗粒相中PCB-28的纬度变化不大。蒸汽压较低的PCB-180在气相中的浓度基本上不随纬度变化,而颗粒相中PCB-180则基本上集中在纬度36。N左右,表明在东亚季风区大气中挥发性较低的POPs化合物具有某种纬度聚焦作用。以宇宙射线成因核素7Be作为大气环流的参照系,可以得出东亚季风区大气环流可影响持久性有机污染物纬度分布的结论。     

CHEMICAL CHARACTERISTICS OF WETLAND′S INFLOW DRY DIFFUSE DUST AND DIRT FROM IMPERVIOUS SURFACE

1INTRODUCTIONIn impervious area dry dustand dirtbuildup con-tains heavy metals,nutrients,pesticides and organ-ics.Many studies(APWA,1969;Sartor and Boyd,1972;Pitt and Amy,1973;Pitt,1979,1985;Yousef and Wanielista,1990;Wanielista andYousef,1993,Ball,et al.…     

Sorption and desorption behavior of residual antidepressants and caffeine in freshwater sediment and sewage sludge

The use of antidepressants is widespread in modern times. Thus, they present a potential risk for ecosystems due to occurrence in domestic sewage containing unaltered metabolites and structures, even after the treatment plants have processed the sewage. The current research investigated the sorption and desorption of antidepressants(citalopram, venlafaxine, fluoxetine, sertraline, and amitriptyline) and caffeine from freshwater sediment and sewage sludge. The samples of freshwater sediment were ...     

Transfeer of organic pollutants during sewage-seawater mixing

The transfer processes of organic pollutants during sewage-seawater mixing were simulated in three different mixing systems. The release rate of organic matter from sewage particles to seawater was found to be about 0.02–0.04 d⁻¹. The release processes can be simulated by an exchange-equilibrium kinetic model. Degradation of COD was observed in all three mixing systems and can be described by a first order kinetic equation. The degradation rate constantk ranged between 0.04 and 0.07 d⁻¹. These results have provided important parameters for estimation of environmental capacity.     

A review of pollutants in the sea-surface microlayer (SML): a unique habitat for marine organisms

Boundary layers between different environmental compartments represent critical interfaces for biological, chemical and physical processes. The sea-surface microlayer (uppermost 1-1000 microm layer) forms the boundary layer interface between the atmosphere and ocean. Environmental processes are controlled by the SML, and it is known to play a key role in the global distribution of anthropogenic pollutants. Due to its unique chemical composition, the upper organic film of the SML represents both a sink and a source for a range of pollutants including chlorinated hydrocarbons, organotin compounds, petroleum hydrocarbons, polycyclic aromatic hydrocarbons (PAH) and heavy metals. These pollutants can be enriched in the SML by up to 500 times relative to concentrations occurring in the underlying bulk water column. The SML is also a unique ecosystem, serving as an important habitat for fish eggs and larvae. Concentration ranges and enrichment factors of pollutants in the SML in different areas of the world's oceans have been critically reviewed, together with available toxicity data for marine biota found within the SML. Overall, the SML is highly contaminated in many urban and industrialized areas of the world, resulting in severe ecotoxicological impacts. Such impacts may lead to drastic effects on the marine food web and to fishery recruitment in coastal waters. Studies of the toxicity of fish eggs and larvae exposed to the SML contaminants have shown that the SML in polluted areas leads to significantly higher rates of mortality and abnormality of fish embryos and larvae.