Status of trace elements in paddy soil and sediment in Taihu Lake region

Thirteen paddy soil profiles and river sediments which are sources of irrigation water were collected around the Taihu Lake, and the trace elements were estimated. The content of La and Ce in paddy soil and sediment were 39.3 and 68.6 mg/kg soil and 36.9 and 65.1 mg/kg soil, being within the range of background values. The values for Pb, Cu, Ni, Cr, Co, Mn, Zn, Se in paddy soil were 23.3, 27.8, 25.5, 63.5, 10.2, 386, 68.7 and 0.25 mg/kg soil respectively, all below the national permission level. There was a decline of Zn in paddy soil. Some of the river sediments were seriously polluted. The river in Yangjin site was most contaminated with 5.47 g Cu/kg and 7.4 g Zn/kg. The high concentration of Pb and Ni also was observed in this sediment. River in Weitang, Huashi, Xinzhuang and Meiyan were contaminated with Pb, Cu and Ni to some extent. Zn, Cu and Pb were the main pollutants in present experiment sites. The fast development of village/township industries have caused severe environmental pollution in the Taihu Lake region, especially irrigation river sediments. Se content in plant and seed was 0.04 and 0.03 mg/kg respectively, showed Se-deficiency in paddy soil in the Taihu Lake region.     

Distribution of toxic trace elements in soil/sediment in post-Katrina New Orleans and the Louisiana Delta

This study provided a comprehensive assessment of seven toxic trace elements (As, Pb, V, Cr, Cd, Cu, and Hg) in the soil/sediment of Katrina affected greater New Orleans region 1 month after the recession of flood water. Results indicated significant contamination of As and V and non-significant contamination of Cd, Cr, Cu, Hg and Pb at most sampling sites. Compared to the reported EPA Region 6 soil background inorganic levels, except As, the concentrations of other six elements had greatly increased throughout the studied area; St. Bernard Parish and Plaquemines Parish showed greater contamination than other regions. Comparison between pre- and post-Katrina data in similar areas, and data for surface, shallow, and deep samples indicated that the trace element distribution in post-Katrina New Orleans was not obviously attributed to the flooding. This study suggests that more detailed study of As and V contamination at identified locations is needed.     

母乳与牛乳中微量元素的比较

用ＩＣＰ－ＡＥＳ法对母乳和牛乳中Ｋ、Ｎａ、Ｃａ、Ｍｇ、Ｐ、Ｆｅ、Ａｌ、Ｚｎ、Ｓｒ、、Ｐｂ、Ｍｎ、Ｂａ和Ｃｕ等１３种元素含量进行了测定。结果发现母乳与牛乳的营养成分差异较大。研究了深入探讨微量元素在人体内重要的生理功能提供了有用的参考数据。     

海河干流、大沽排污河沉积物中有机氯农药的残留状况

调查了海河干流和大沽排污河沉积物中持久性有机氯杀虫剂(OCPs)的残留状况.在所选取的16个断面沉积物样品中均有大量HCHs、DDTs检出,表明海河和大沽排污河的DDT和HCH污染相当严重.海河沉积物中HCHs和DDTs总质量浓度分别为3.30～75.96、1.57～221.57 ng/g.大沽排污河沉积物中HCHs和DDTs的残留量分别为2.30～124.61、11.28～237.30ng/g.与国内外部分河流表层沉积物中HCHs、DDTs的含量相比,海河和大沽排污河沉积物中有机氯农药含量较高.最后根据两条河流沉积物中的OCPs的残留量,分析了其可能的污染源.     

Impact of a flood disaster on sediment toxicity in a major river system--the Elbe flood 2002 as a case study

The ecotoxicological implications of a flooding disaster were investigated with the exceptional Elbe flood in August 2002 as an example. Sediment samples were taken shortly after the flood at 37 sites. For toxicity assessment the midge Chironomus riparius (Insecta) and the mudsnail Potamopyrgus antipodarum (Gastropoda) were exposed to the sediment samples for 28 days. For a subset of 19 sampling sites, the contamination level and the biological response of both species were also recorded before the flood in 2000. The direct comparison of biological responses at identical sites revealed significant differences for samples taken before and immediately after the flood. After flood sediments of the river Elbe caused both higher emergence rates in the midge and higher numbers of embryos in the mudsnail. Contrary to expectations the toxicity of the sediments decreased after the flood, probably because of a dilution of toxic substances along the river Elbe and a reduction in bioavailability of pollutants as a result of increasing TOC values after the flood.     

Lead concentrations in soil, sediment and clam samples from the Pungo River peatland area of North Carolina, USA

Lead (Pb) concentrations were measured in samples of peat soils, sediments and clams (Rangia cuneata) collected from the Pungo River region of coastal North Carolina. In peat soils, mean Pb concentrations (dry weight +/- 1 SD) were significantly higher (p<0.05) in surface samples (12.8microg g(-1)+/-7.6) than in samples from depths of 20 cm (2.7microg g(-1)+/-2.7) or 1 m (3.6microg g(-1)+/-3.6). Mean Pb concentrations in surface sediments from canals draining peatlands and from the Pungo River which receives this drainage ranged from 0.1microg g(-1)+/-0.1 to 7.0microg g(-1)+/-0.6. These Pb concentrations are similar to values reported in other studies for areas considered uncontaminated. Fractionation analysis revealed that the majority of the Pb in the peat and sediment samples was associated with the residual fraction, with lesser amounts in the organically-bound fraction, and generally negligible amounts in the water-soluble fraction. These results indicate that the bulk of the Pb in the soils and sediments of this area is relatively immobile and non-bioavailabe. This is supported by the relatively low concentrations of Pb (0.2-0.5 microg g(-1), dry weight) observed in soft tissues of R. cuneata collected from the Pungo River.     

Evaluation of genotoxicity and toxicity of water and sediment samples from a Brazilian stream influenced by tannery industries

This paper reports results of genotoxicity and toxicity studies of water and sediment samples collected from the Estancia Velha stream of southern Brazil, a stream transporting both domestic sewage and effluents from regional factories working in the leather industry. Three sites were selected: in the stream headwaters (Site 1), located downstream of an urban area (Site 2), and near the basin outfall (Site 3). Results obtained with Allium cepa showed no evidence of chromosomal mutation, either in water or in sediment, during winter or summer seasons, but samples collected below Site 1 showed high toxicity. Physical and chemical analyses showed high concentrations of pollutants at these sites. Ecotoxicity tests with Daphnia magna and Ceriodaphnia dubia measured toxicity in water from Sites 2 and 3 in summer 2004. A toxic effect on Hyalella azteca was only found in sediment from Site 3 during winter 2003 and summer 2004. The results suggest that the synergy among different compounds in domestic and industrial sewage discharges can make it difficult to maintain system stability.     

Sorption and photolysis studies in soil and sediment of the herbicide napropamide

Abstract

The influence of soil and sediment composition on sorption and photodegradation of the herbicide napropamide [N, N‐diethyl‐2‐(1‐naphthyloxy)propionamide] was investigated. Five soils and one sediment were selected for this study and the clay fractions were obtained by sedimentation. Sorption‐desorption was studied by batch equilibration technique and photolysis in a photoreactor emitting within 300–450 nm wavelenght with a maximum at 365 nm. Sorption increased with clay content and was not related to organic matter *content. High irreversibility of sorption was related to the greater montmorillonite content. The presence of soil or sediment reduced photolysis rate due to screen effect and this process did not depend on solid composition but on particle size distribution.     

Contamination by arsenic and other trace elements of tube-well water along the Mekong River in Lao PDR

Arsenic and other trace element concentrations were determined for tube-well water collected in the Lao PDR provinces of Attapeu, Bolikhamxai, Champasak, Savannakhet, Saravane, and Vientiane. Water samples, especially from floodplain areas of central and southern Laos, were significantly contaminated not only with As, but with B, Ba, Mn, U, and Fe as well. Total As concentrations ranged from <0.5 μg L⁻¹ to 278 μg L⁻¹, with over half exceeding the WHO guideline of 10 μg L⁻¹. 46% of samples, notably, were dominated by As(III). Samples from Vientiane, further north, were all acceptable except on pH, which was below drinking water limits. A principal component analysis found associations between general water characteristics, As, and other trace elements. Causes of elevated As concentrations in Lao tube wells were considered similar to those in other Mekong River countries, particularly Cambodia and Vietnam, where young alluvial aquifers give rise to reducing conditions.     

Sorption and photolysis studies in soil and sediment of the herbicide napropamide

The influence of soil and sediment composition on sorption and photodegradation of the herbicide napropamide [N,N-diethyl-2-(1-naphthyloxy)propionamide] was investigated. Five soils and one sediment were selected for this study and the clay fractions were obtained by sedimentation. Sorption-desorption was studied by batch equilibration technique and photolysis in a photoreactor emitting within 300-450 nm wavelength with a maximum at 365 nm. Sorption increased with clay content and was not related to organic matter content. High irreversibility of sorption was related to the greater montmorillonite content. The presence of soil or sediment reduced photolysis rate due to screen effect and this process did not depend on solid composition but on particle size distribution.     

Molecularly imprinted polymers for the detection of benomyl residues in water and soil samples

Benomyl is a benzimidazol fungicide used against various crop pathogens. Although banned in many countries, it is still widely used worldwide and is listed in different monitoring programs among the substances to be monitored to assess human exposure to pesticide residues. The assessment of benomyl is mainly based on the analysis of the residues of its most important metabolite, carbendazim. Existing methods often lack of selectivity and display a limited performance because of the presence of co-extracted compounds. Molecularly imprinted polymers (MIPs) offer an alternative methodology, adsorbing preferentially those target molecules for which the polymers are specifically prepared. In this study, we optimized the synthesis of a polymer imprinted with benomyl. Tests of specificity recognition showed a good performance for carbendazim compared with other similar pesticides. The mean recovery of benomyl (measured as carbendazim) from water samples was estimated to be 90% for MIPs while with real soil samples collected in Morocco the recovery efficiency was 62%. Preliminary tests also suggest that this MIP can implement traditional SPE techniques for assessing benomyl residual concentrations in environmental samples.     

Effect of organic amendments on the mobility of trace elements in phytoremediated techno-soils: role of the humic substances

The efficiency of aided phytostabilization using organic amendments such as ramial chipped wood (RCW) and composted sewage sludge (CSS) was studied on contaminated techno-soils, on nine experimental plots. The objective was to characterize the role of fulvic (FA) and humic acids (HA) on the mobilization of trace elements, specifically As, Cu, Mo, Pb and Zn. Results showed that the addition of CSS increased the total organic carbon and nitrogen content more than with RCW and as a result, the C/N ratio in the CSS soil was higher than in the RCW and non-amended (NE) soil, reflecting the high decomposition of soil organic matter in the CSS soil compared with the other soils. The RCW and CSS amendments increased the hydrogen index (HI) values and the oxygen index (OI) values compared with the NE soil, especially for the soil treated with CSS which contained more aliphatic than aromatic compounds. The addition of CSS to the techno-soil significantly increased the percentage of C _org associated with the HA fractions compared with the RCW and NE soils. The soil amended with CSS showed the highest E ₄/E ₆ ratio and the lowest E ₂/E ₃ ratio of FA. Zn and As were more abundant in the FA fraction than in the HA fraction, whereas Pb, Cu and Mo were more associated to HA than to FA in the treated and untreated soils, which may explain the difference in their mobility and availability.     

An enzyme-linked immunosorbent assay for the determination of dioxins in contaminated sediment and soil samples

A 96-microwell enzyme-linked immunosorbent assay (ELISA) method was evaluated to determine PCDDs/PCDFs in sediment and soil samples from an EPA Superfund site. Samples were prepared and analyzed by both the ELISA and a gas chromatography/high resolution mass spectrometry (GC/HRMS) method. Comparable method precision, accuracy, and detection level (8 ng kg(-1)) were achieved by the ELISA method with respect to GC/HRMS. However, the extraction and cleanup method developed for the ELISA requires refinement for the soil type that yielded a waxy residue after sample processing. Four types of statistical analyses (Pearson correlation coefficient, paired t-test, nonparametric tests, and McNemar's test of association) were performed to determine whether the two methods produced statistically different results. The log-transformed ELISA-derived 2,3,7,8-tetrachlorodibenzo-p-dioxin values and log-transformed GC/HRMS-derived TEQ values were significantly correlated (r=0.79) at the 0.05 level. The median difference in values between ELISA and GC/HRMS was not significant at the 0.05 level. Low false negative and false positive rates (<10%) were observed for the ELISA when compared to the GC/HRMS at 1,000 ng TEQ kg(-1). The findings suggest that immunochemical technology could be a complementary monitoring tool for determining concentrations at the 1,000 ng TEQ kg(-1) action level for contaminated sediment and soil. The ELISA could also be used in an analytical triage approach to screen and rank samples prior to instrumental analysis.     

The influence of maize residues on the mobility and binding of benazolin: investigating physically extracted soil fractions

The amount of non-extractable residues and the distribution of benazolin and its metabolites were evaluated three months after herbicide application (14C-labelled) in physically extracted soil fractions of topsoil layers of undisturbed soil columns with and without incorporated maize straw (14C-labelled). In addition, a variety of wet-chemical and spectroscopic methods were used to characterise the structure of organic carbon within the different soil fractions. The addition of crop residues increased the amount of dissolved organic carbon, enhanced the aromaticity of the organic carbon structure and enforced the aggregation of organomineral complexes. After incorporation of crop residues, an increase in the formation of metabolic compounds of benazolin and of non-extractable residues was detected. These results indicate that the addition of crop residues leads to a decrease in mobility and bioaccessibility of benazolin and its metabolites.     

GC/MS analysis of polynuclear aromatic hydrocarbons in sediment samples from the Niger Delta region

Thirteen sediment samples from different locations in the Niger Delta region of Nigeria were analyzed for the presence of 16 polynuclear aromatic hydrocarbons (PAHs) via gas chromatography/mass spectrometry. The specific target compounds for this study included naphthalene, acenaphthylene, acenaphthene, flourene, phenanthrene, anthracene, flouranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]flouranthene, benzo[a]pyrene, benzo[ghi]perylene, dibenz[a,h]anthracene, and indeno[1,2,3-cd]pyrene. Four isotopically labeled polynuclear aromatic hydrocarbons (acanaphthene-d10, phenanthrene-d10, chrysene-d12 and perylene-d12) were used for internal standardization. All 16 PAHs were found in most of the thirteen samples with concentration ranging from 0.1 microg/kg to 28 microg/kg. It was also found that the 5 and 6-ring PAHs were present in higher concentrations than all the other compounds, indicating their high resistance to microbial degradation.     

Factors affecting distribution and mobility of trace elements (Cu, Pb, Zn) in a perennial grapevine (Vitis vinifera L.) in the Champagne region of France

Soil and Vitis vinifera L. (coarse and fine roots, leaves, berries) concentration and geochemical partitioning of Cu, Pb and Zn were determined in a contaminated calcareous Champagne plot to assess their mobility and transfer. Accumulation ratios in roots remained low (0.1-0.4 for Cu and Zn, <0.05 for Pb). Differences between elements resulted from vegetation uptake strategy and soil partitioning. Copper, significantly associated with the oxidisable fraction (27.8%), and Zn with the acid soluble fraction (33.3%), could be mobilised by rhizosphere acidification and oxidisation, unlike Pb, essentially contained in the reducible fraction (72.4%). Roots should not be considered as a whole since the more reactive fine roots showed higher accumulation ratios than coarse ones. More sensitive response of fine roots, lack of correlation between chemical extraction results and vegetation concentrations, and very limited translocation to aerial parts showed that fine root concentrations should be used when assessing bioavailability.     

Bioaccessibility of trace elements as affected by soil parameters in smelter-contaminated agricultural soils: a statistical modeling approach

An investigation was undertaken to identify the most significant soil parameters that can be used to predict Cd, Pb, and Zn bioaccessibility in smelter-contaminated agricultural soils. A robust model was established from an extended database of soils by using: (i) a training set of 280 samples to select the main soil parameters, to define the best population to be taken into account for the model elaboration, and to construct multivariate regression models, and (ii) a test set of 110 samples to validate the ability of the regression models. Total carbonate, organic matter, sand, P(2)O(5), free Fe-Mn oxide, and pseudototal Al and trace element (TE) contents appeared as the main variables governing TE bioaccessibility. The statistical modeling approach was reasonably successful, indicating that the main soil factors influencing the bioaccessibility of TEs were taken into account and the predictions could be applicable for further risk evaluation in the studied area.     

Distribution and accumulation of major and trace elements in water,sediment, and fishes from protected areas of the Atlantic Rainforest

Environmental Science and Pollution Research - Environmental pollution affects the quality of the natural environment where major and trace elements have been commonly found to accumulate in biotic...     

Total dissolved and bioavailable elements in water and sediment samples and their accumulation in Oreochromis mossambicus of polluted Manchar Lake

The concentrations of 15 elements were determined in water, sediment and tissues of fish (Oreochromis mossambicus) collected from five sampling stations of Manchar Lake in 2005 for two successive seasons, winter (WS) and summer (SS). Elements analysis was performed by atomic absorption spectrometry with flame (FAAS) and electrothermal (ETAAS) modes, using multielement standard solution. The obtained results show that, the trace and toxic elements (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and macronutrients (Al, Ca, K, Mg and Na) concentrations in lake water were above the recommended drinking water standards by WHO. Concentrations of Na detected in lake water in WS and SS, were in the range of 445.5-562.7 and 420.6-643.5 mgl(-1), respectively. While among toxic elements As concentration in both seasons, have been found in the range of 60.4-88.9 and 64.9-101.8 microgl(-1) respectively, these values are 6-10 times higher than the permissible limit of WHO. The mean concentrations of elements understudy in muscles of fish were found as 2.35, 1.39, 0.46, 2.3, 1517.9, 2.2, 2.4 and 188.9 mgkg(-1) for As, Cd, Cr, Cu, Fe, Ni, Pb and Zn, respectively. High accumulation of toxic elements in fish tissues is indicating that some of the metal contaminants are entering the food chain. Correlations among the variables were identified by multivariate analysis. The extraction of elements from sediments with EDTA, to predict the bioavailability of trace and toxic elements, has shown that among them As, Cd and Zn were the most bioavailable elements in lake sediment.     

Sources and trends of trace elements and polycyclic aromatic hydrocarbons in a shallow lake in the Mediterranean area from sediment archives of the Anthropocene

Environmental Science and Pollution Research - In this study, the anthropogenic contamination in Trasimeno lake (Central Italy) was investigated using three sediment cores spanning over the last...