Trace elements and organochlorine pollutants in selected fish species from Lake Phewa,Nepal

Lake water and fish livers and gills of sahar (Tor putitora), spiny eel (Mastacembelus armatus), African magur (Clarias gariepinus), and tilapia (Oreochromis niloticus) from Lake Phewa, Nepal, were assessed for the concentrations of trace metals/elements and persistent organic pollutants. The lake water was neutral with low ionic and metallic concentrations as compared to high-altitude lakes of Nepal. The four elements Cu, Zn, Se, and Cd had highest concentrations in livers, indicating uptake from diet, whereas four other metallic elements Cr, Mn, Ni, and Pb had highest concentrations in gills, indicating uptake from lake water. O. niloticus tended to have most of trace metals in the liver at higher concentrations than the other species but significant differences among the different species were found only for Mn, Ni, and Zn in the gills. A pilot study on the concentrations of persistent organic pollutants in muscle revealed that dichlorodiphenyltrichloroethane and related compounds were the dominant organochlorine pesticides, having highest concentrations in C. gariepinus and lowest in O. niloticus.     

Bioaccessibility of metals in soils and dusts contaminated by marine antifouling paint particles

Fragments of antifouling paint and environmental geosolids have been sampled from the island of Malta and analysed for total and bioaccessible metals. Total concentrations of Ba, Cd, Cu, Pb, Sn and Zn were two to three orders of magnitude higher in spent antifouling composites relative to respective values in background soils and road dusts. Paint fragments were visible in geosolids taken from the immediate vicinity of boat maintenance facilities and mass balance calculations, based on Ba as a paint tracer, suggested that the most contaminated soils, road dusts and boatyard dusts contained about 1%, 7% and 9%, respectively, of antifouling particles. Human bioaccessibilities of metals were evaluated in selected samples using a physiologically based extraction technique. Accessibilities of Cd, Cu, Pb and Zn in the most contaminated solids were sufficient to be cause for concern for individuals working in the boat repair industry and to the wider, local community.     

Bags with oven-dried moss for the active monitoring of airborne trace elements in urban areas

To define a harmonized methodology for the use of moss and lichen bags as active monitoring devices of airborne trace elements in urban areas, we evaluated the element accumulation in bags exposed in Naples in different spring weather conditions for 6- and 12-weeks. Three different pre-exposure treatments were applied to moss and lichen materials: water-washing, acid-washing and oven-drying. During the different exposure periods in the Naples urban environment the moss accumulated always higher amounts of elements (except Hg) than lichens and the element accumulation increased during wetter weather and higher PM₁₀ conditions. The oven pre-treatment did not substantially modify the morphology and element composition of moss and the exposure in bags of this material for 6-weeks was sufficient to detect the pattern of airborne trace elements.     

Influence of macroalgal diversity on accumulation of radionuclides and heavy metals in Bulgarian Black Sea ecosystems

Radionuclides and heavy metals were studied in green, brown and red Black Sea macroalgae by low-level gamma spectrometry and atomic absorption spectrometry. The samples were collected along the whole Bulgarian coast from 1996 to 2004. The levels have been depending on algae species, locations and year of sampling. The highest ¹³⁷Cs levels were found in red Ceramium rubrum species from all studied locations, while ²²⁶Ra and ²¹⁰Pb were up to three orders of magnitude higher in Bryopsis plumosa. The data showed that the red algae species (Rhodophyta) accumulate more heavy metals than the other phyla (except for Fe whose values were higher in green algae). The data confirmed that algae are valuable indicators of the environmental contamination. The observed elevated levels were mainly due to Danube, Dnieper and Dnester inputs in the NW corner of the Black Sea.     

Uptake of radionuclides and stable elements from paddy soil to rice: a review

The critical paths for radionuclides and the critical foods in Asian countries differ from those in Western countries because agricultural products and diets are different. Consequently, safety assessments for Asian countries must consider rice as a critical food. As most rice is produced under flooded conditions, the uptake of radionuclides by rice is affected by soil conditions. In this report, we summarize radionuclide and stable element soil-to-plant transfer factors (TFs) for rice. Field observation results for fallout ¹³⁷Cs and stable Cs TFs indicated that while fallout ¹³⁷Cs had higher TF than stable Cs over several decades, the GM (geometric mean) values were similar with the GM of TF value for ¹³⁷Cs being 3.6 × 10⁻³ and that for stable Cs being 2.5 × 10⁻³. Although there are some limitations to the use of TF for stable elements under some circumstances, these values can be used to evaluate long-term transfer of long-lived radionuclides in the environment. The compiled data showed that TF values were higher in brown rice than in white rice because distribution patterns for elements were different in the bran and white parts of rice grains.     

大气颗粒物样品中主量和痕量元素的直接测定

采用一种新的标样制备方法,用波长色散X射线荧光光谱直接定量分析由微孔滤膜抽滤所吸附和收集的大气颗粒物中主量和痕量无机元素.具有快速、简便、准确和经济等特点.     

Trace Metal Contents (Al, Cu and Zn) of Tea: Tea and Soil from Two Tea Plantations, and Tea Products from Different Provinces of China

The present project aims to investigate the possible contamination of teas with the trace metals: Al, Cu and Zn. Tea bushes sampled from two tea plantations in the northern part of Guangdong Province accumulated higher concentrations of Cu and Zn in young leaves, and of Al in old leaves. The analysis of the three metals in tea produced in different provinces indicated higher Al levels in those obtained from Guangdong and Yunnan Provinces, which may be due to the lower soil pH in these areas. Green tea had the lowest Al concentration among the four types of tea studied, as only the bud and two young leaves are used, whereas older leaves are used for other types of tea (black, Oolong and Puerh tea). The transfer of Al, Cu and Zn from soil to different parts of tea bushes was low in general, except for Zn at Lechang tea plantation which next to a Pb/Zn mine, where a higher transfer was observed from young leaves to tea products, indicating possible metal contamination during tea processing. However, low concentrations of Cu and Zn (less than 0.07 mg Cu L^-1 and 0.17 mg Zn L^-1), and moderate amounts of Al (2.1-2.5 mg L^-1) were obtained in the tea liquor (1% hot water extracts).     

Seasonal variation and partition of trace metals (Fe, Zn, Cu, Mn, Cr, Cd and Pb) in surface sediments: relationship with physico-chemical variables of water from the Calabar River, South Eastern Nigeria

The seasonal variation and partition of trace metals (Fe, Cu, Zn, Mn, Cd, Cr and Pb) in the surface sediments of the Calabar River are reported. Chemical partition of the metals in the sediments reveals that 2–30% of the total metal load was contributed by the non-detrital (acid-soluble) fraction, while fine-grained host minerals/compounds are the main carriers of the detrital (acid-insoluble) fraction (70–98%). Using multivariate statistical analysis, the seasonal fluctuations in the distribution of some of the metals show significant influence by physio-chemical changes (dissolved oxygen, pH, salinity and conductivity) in the water column. Fe–Mn oxide grain coatings and sulphide materials have been identified as scavengers of some of the non-detrital and detrital trace metals in the sediments. On the basis of index of geoaccumulation (I-geo) and comparison with previous studies, the Calabar River surface sediments have been classified as unpolluted.     

香溪河流域不同介质中碳、氮、磷的分布特征及相关性研究

为了解香溪河流域碳、氮、磷的分布情况及水、陆生态系统中这些生源要素间的相互关系,对流域内河岸带土壤、河流水体及沉积物中总有机碳(TOC)、总氮(TN)、总磷(TP)含量进行调查,分析它们在流域内的分布特点,探讨各要素在3种介质间的相关性及随河流级别的变化规律。研究发现,超过60%的样点土壤中TOC、TN含量处于"较丰富"或"丰富"等级,耕地附近样点的TOC、TN和磷矿区附近样点的TP普遍偏高。河流水体及沉积物中各要素的含量都与土壤中的含量紧密相关,但水、陆介质间TP的相关性较TOC、TN强。低级别河流样点土壤中TOC、TN、C/P、N/P值和沉积物中C/P及N/P值整体较高级别河流样点高。结果表明:以磷矿开发和农业施肥为代表的人类活动,对香溪河流域内生源要素的含量及分布产生了显著影响;水体中P元素含量与陆源关系最强,在水体污染控制中应予以重视。     

Metal and metallothionein level in the heat-treated cytosol of gills of transplanted mussels Mytilus galloprovincialis Lmk

A stock of mussels Mytilus galloprovincialis was transplanted over 1 year to four sites in a semi-enclosed bay in Croatia which is under the influence of various sources of pollution. The positive correlation of metal (Cd, Zn, Cu, Mn, Fe) and metallothionein (MT) tissue contents based on the analysis of heat-treated cytosol of gills with shell mass, as an indicator of mussel age, indicated to accumulation of metals, as well as the increase of MTs with mussel age. The principal component analysis (PCA) revealed that 74% of total variance of obtained results could be explained through two principal components. The first principal component was highly correlated with MT, Cd and Zn indices (metal or MT content/shell mass), and the second one with Cu, Mn, and Fe indices, as well as the gill index. High correlation of MTs with Zn and Cd is consistent with their affinity for binding to MTs.