Abstracts to forthcoming papers

Food is the major source of metal exposure for the nonsmoking general population. Food samples of plant and animal origin from Ismailia, Egypt, were analyzed for the content of cadmium (Cd), lead (Pb), chromium (Cr), zinc (Zn), and copper (Cu) using AAS. The Cr, Zn, and Cu concentrations were in the range of 1.7–249?µg?kg^?1 wet weight (ww), 2–66?mg?kg^?1?ww, and 0.5–3.46?mg?kg^?1?ww, respectively. The mean daily intake of Cr, Zn, and Cu was 28.9?µg day^?1, 8.55?mg day^?1, and 1.7?mg day^?1, respectively. The intake estimates are within the range of the recommended intake established internationally. Concentrations of Cd and Pb were in the range of 10–321?µg?kg^?1?ww and 31–1200?µg?kg^?1?ww, respectively. The weekly dietary intake for Cd and Pb (4.02 and 20.4?µg?kg^?1 b.w, respectively) is lower than the FAO/WHO PTWI. Bread is the foodstuff that provided the highest rate of Pb and Cd (62 and 46% of the daily intake) to adults in Ismailia city.     

Contamination status of arsenic,lead, and cadmium of different wetland waters

The present investigation was conducted to determine the contamination status of arsenic (As), cadmium (Cd), and lead (Pb) in the wetland waters of Bhaluka in Bangladesh. Water samples were collected from 15 selected wetlands of Bhaluka region and analyzed using an atomic absorption spectrophotometer. Estimated results of three metals detected were As (7–80?µg?L^?1), Pb (0–86?µg?L^?1) and Cd (0–70?µg?L^?1) in water samples in all wetlands. The level of As in all investigated wetlands (93%) was higher than that of WHO recommended permissible limit of drinking water except Alanga wetland. However, As levels were higher than that recommended for livestock water quality levels. Eighty-seven percent of the investigated wetlands showed lower content of Pb than WHO recommended permissible limit of drinking water, but two wetland waters (Dohuria-1 and Chowdhuri) were polluted with higher Pb levels. Sixty-seven percent of the investigated wetlands displayed higher levels of Cd than WHO recommended permissible limit in drinking water. Dissolved organic material showed no significant difference among the 15 investigated wetlands water, but total dissolved solids was significantly greater. The condition of the water of all wetlands was basic pH. All water samples were applied to linear regression equation and correlation coefficients where values showed no significant differences. Data demonstrate that the estimated high metal concentrations of these ponds may contribute to bioaccumulation within plants, food grains and shrimp.     

Preliminary survey of pharmaceutical residues in some important Romanian rivers

A number of important rivers of Romania were investigated for pharmaceutical and antifungal residues. In a post target approach analysis, a single-stage, high-resolution mass spectrometry was successfully applied for the screening of 43 pharmaceuticals and fungicides in water, using U-HPLC-Exactive Orbitrap MS at 50,000 full width at half maximum resolution. Detection was based on accurate masses and retention times. The study confirmed the presence of pharmaceuticals and antifungals such as diclofenac, sulfamethoxazole, carbamazepine, trimethoprim, thiabendazole, and clotrimazole, in water. Diclofenac and carbamazepine were the most frequently detected (eight samples); concentrations ranged from 5 to 50 ng L^?1. Low concentrations of griseofulvin were detected in the Prut River. Further monitoring studies should be carried out in order to fill the gaps of knowledge concerning the presence of pharmaceutical residues in Romanian water environment and to improve public understanding regarding the environmental risk of pharmaceutical contamination.     

Denitrification in bottom sediment near oil production facilities off the Louisiana Gulf Coast

There is little information on denitrification in Gulf of Mexico bottom sediment. Potential denitrification rates in surface sediment were measured along transects legs extending 0–800 m from two offshore oil production platforms. The average potential denitrification ranged from approximately 50 mg N m^?2 d^?1 in surface sediment near the platforms to 15 mg N m^?2 d^?1 in sediment 800 m from the platforms. Measured denitrification rates were correlated to a higher organic matter content in sediment nearer the platforms. This research examined only a small component of nitrogen processing in Gulf of Mexico sediment. Additional research should examine the effect of nitrogen loading and temporal and spatial variability on denitrification rate.     

Estimation of methane emitted by natural wetlands of Orissa: Based on case studies on three representative wetlands

The rapid increase in the concentration of greenhouse gases in our atmosphere has led to significant changes in global climate. Methane is second to carbon dioxide in terms of its contribution to global warming. The wetlands serve as a major natural source of methane. Orissa State, located on the east coast of India, has a number of natural wetlands. Three representative wetlands: Chilka – the largest semi-saline lake of Asia, Anshupa – a land-locked fresh water lake and Gahirmatha – a tidal flood plain of Bhitara Kanika region that has sprawling mangrove vegetation (extension of the Sunderbans of the Gangetic delta) were chosen for intensive monitoring of water and sediment quality, along with methane flux over a period of three years during 1997–2000. The average seasonal methane fluxes were integrated to arrive at the annual flux from each wetland category. Finally, those results were extended to other natural wetlands of Orissa to arrive at the average annual methane flux of Orissa State. This is useful in calculating the total budget of greenhouse gases of India.     

Serial variations of trace metal concentrations in aquatic insect Stenopsyche marmorata

Caddisfly larvae (Stenopsyche marmorata) instar V, periphyton, sediment and river water at a non‐contaminated upstream site, a metallic contaminated downstream site, and industrial wasterwater which caused the metallic contamination were collected once a month for 21 months. Nickel (Ni), copper (Cu), zinc (Zn), and lead (Pb) concentrations in these samples were measured. Significant serial variations of the 4 metal concentrations in the larvae showed a seasonal tendency at the upstream site but not at the downstream site. The larvae more clearly indicated the influence of industrial wastewater than periphyton. As the larvae of Stenopsyche marmorata could be collected throughout the year, this larva is useful for monitoring trace metal contamination in rivers.     

Mercury concentrations in the surface sediments of the intertidal area along the west coast of Peninsular Malaysia

Total mercury (Hg) levels in the intertidal surface sediments along the west coast of Peninsular Malaysia were analysed by using heat vaporization method. Total Hg levels in these sediments ranged from 3.00 to 201?µg?kg^?1 dry weight with a mean concentration of 60.0?µg?kg^?1 dry weight. More than 90% of the samples studied have the total Hg concentrations less than 150?µg?kg^?1 dry weight. Compare with the regional data and sediment quality guidelines, the Hg contamination in the intertidal area along the west coast of Peninsular Malaysia was not serious, except for a few sites that might have received anthropogenic Hg in the samples collected between 1999 and 2000. It is suggested that a similar study of heavy metals in the sediments of the west coast of Peninsular Malaysia be conducted regularly.     

螯合剂和表面活性剂辅助金福菇修复重金属污染土壤

通过温室大棚盆栽试验,研究螯合剂和表面活性剂单独或复合处理辅助金福菇修复重金属污染土壤的效果.结果表明,单独添加EDTA(乙二胺四乙酸)时,高浓度的EDTA(E2,5 mmol kg-1)使金福菇的生物量比对照降低26%,子实体Pb、Cu和Cd的浓度分别比对照提高15～88倍、0.8～3.3倍和0.5～0.6倍.单独添加表面活性剂时,各处理生物量与对照没有显著差异,且重金属浓度变化幅度没有单独添加EDTA的处理大.低浓度的表面活性剂对金福菇吸收各种重金属的影响较小,而高浓度则影响较大,但与表面活性剂及重金属种类有关.共同添加EDTA和表面活性剂时,只有当EDTA和CTAB(溴化十六烷基三甲铵)共同添加时,EC2(EDTA:CTAB=1:1)和EC3(EDTA:CTAB=2:1)的生物量显著降低,其余处理与对照差异不明显.EC3的子实体Pb和Cu浓度达到所有处理中的最大值,分别为(1 533.61±131.34)、(1 786.11±328.33)mg kg-1.EDTA和SDS(十二烷基磺酸钠)浓度比为2:1(ES3)时,子实体Cd浓度达到最大值,为(50.56±11.55)mg kg-1.此外,还分析了不同处理的重金属总积累量和富集系数.结果显示,在螯合剂和表面活性剂辅助下,金福菇修复复合重金属污染土壤具有很大的潜能.     

北京官厅水库水体中挥发性有机物健康风险评价

为研究北京官厅水库水体中挥发性有机物对人体产生的潜在健康危害风险,从9个有代表性的采样点采集水样,用顶空气相色谱法测定了挥发性氯代烃的质量浓度,所检测的5种挥发性氯代烃的质量浓度总量为5.33～97.74 ng/L,同时讨论了其污染水平和分布特点.应用美国环境保护署(US EPA)的健康风险评价方法,对官厅水库水体中挥发性氯代烃通过食入和皮肤接触2种途径进入人体的危害进行了风险计算和初步评价. 结果表明:水库中各采样点的非致癌风险和致癌风险均未超标,从位于桑干河八号桥的6号采样点采集的水样中挥发性氯代烃的非致癌风险值达到10－4数量级,其余采样点的非致癌风险值均在10-5数量级;各采样点的致癌风险指数远远低于10－4的数量水平. 因此,初步认为目前官厅水库水体中挥发性氯代烃不会对人体产生明显的健康危害.      

福建省菜园土壤重金属的含量及其污染评价

采集了福建省26个县市158份菜园表层土壤样品,测定了土壤样品中重金属含量,采用单项及综合污染指数法对土壤重金属污染进行评价分析,并通过元素相关性分析和聚类分析,研究了菜园土壤重金属元素的赋存特征与区域分布.结果表明,福建省菜园土壤存在着不同程度的重金属污染,主要污染元素为Pb,Hg和Cd;元素相关性分析与聚类分析的结果表明:Cu,Zn,Ni和As具有伴随污染的特点,其污染源主要来自土壤母质和大量施用的农药和化肥;Cd,Pb和Hg在土壤中各聚成一类,说明它们在菜园土壤具有较独特的污染源,特别是Cd和Hg,其污染特征明显.而Pb和Cd虽有各自的污染源,但其污染具有一定的相关性.