Status of metal levels and their potential sources of contamination in Southeast Asian rivers

To assess the concentration and status of metal contaminants in four major Southeast Asian river systems, water were collected from the Tonle Sap–Bassac Rivers (Cambodia), Citarum River (Indonesia), lower Chao Phraya River (Thailand), and Saigon River (Vietnam) in both dry and wet seasons. The target elements were Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Ba, Tl, and Pb and the concentrations exceeded the background metal concentrations by 1- to 88-fold. This distinctly indicates enrichment by human urban area activities. The results of a normalization technique used to distinguish natural from enriched metal concentrations confirmed contamination by Al, Cd, Co, Mn, Ni, Pb, and Zn. Cluster analysis revealed the probable source of metals contamination in most sampling sites on all rivers studied to be anthropogenic, including industrial, commercial, and residential activities. Stable lead isotopes analyses applied to track the sources and pathways of anthropogenic lead furthermore confirmed that anthropogenic sources of metal contaminated these rivers. Discharges of wastewater from both industrial and household activities were major contributors of Pb into the rivers. Non-point sources, especially road runoff and street dust, also contributed contamination from Pb and other metals.     

The conservation status and trends of raptors and owls in Europe

To conserve biodiversity efficiently, an international framework is needed to ensure that national priorities take into account regional and global priorities. BirdLife International has published five comprehensive assessments of the global status of the world's birds and two evaluations of the status of Europe's birds at a continental level. This paper analyzes the results of these assessments in relation to Europe's 56 species of raptors and owls, 18% of which are of global conservation concern, and 64% of which have an unfavorable conservation status in Europe. The European Union (EU) holds half of the total estimated European breeding population of raptors and owls, and European Russia supports another third, but every European country has a responsibility for at least two species of European conservation concern. During the 1990s, more raptors increased than decreased in most EU member states, but the opposite was true in eastern Europe, where many of the most threatened species are concentrated. Given the popularity of these species with the public, and the political commitment to halt the loss of biodiversity by 2010, much more action is needed to monitor and conserve birds of prey.     

Influence of oil contamination levels on hydrocarbon biodegradation in sandy sediment

The influence of oil concentration on hydrocarbon biodegradation in a sandy sediment was studied in polyvinyl chloride reactors (0.45 x 0.28 x 0.31 m) containing 76.8 kg of beach sand in natura, where the upper layer was artificially contaminated with petroleum. The oil-degrading microorganisms used consisted of a mixed culture named ND, obtained from landfarming and associated with indigenous microorganisms. On the 28th day of the process, the degradation in reactors containing sandy sediment contaminated with light Arabian oil and presenting an initial oil content of 14, 21 or 28 g kg-1 reached the following levels (%): 33.7, 32.9 and 28.9 for oil and grease; up to 88.3, 35.3 and 13.0 for C14-C26 n-alkanes; and 100, 61.3 and 59.4 for pristane, respectively. Phytane removal (37.1%) was only detected in the reactor contaminated with the lowest oil concentration studied. These results, together with the expressive bacterial growth observed (from 10(6) to 10(11) cfu g-1) give strong support to the argument that biodegradation was the dominant component of the remediation process. Susceptibility to biodegradation was inversely proportional to increasing oil contamination. The degradation of branched alkane: pristane was not repressed by the presence of n-alkanes.     

Heavy metal contamination in surface sediments from lakes and their surrounding topsoils of China

Environmental Science and Pollution Research - Due to rapid urbanization, industrialization, agricultural development, and mining activities, soil heavy metal pollution has become a severe issue in...     

Anticoagulant rodenticide exposure in raptors from Ontario,Canada

Environmental Science and Pollution Research - Anticoagulant rodenticides (ARs) are used globally to control rodent pest infestations in both urban and agricultural settings. It is well documented...     

Changes in pigment concentration and composition in Norway spruce induced by long-term exposure to low levels of ozone

Rametes of Norway spruce were fumigated with 30 ppb (nl litre(-1)) ozone above ambient level for 4 years in open-top chambers. They were grown under different light conditions, because some of the chambers received approximately 10% less light than the others. Samples from three age classes were analyzed for nitrogen and pigments using HPLC. It could be demonstrated that the ozone treatment reduced the concentration of chlorophyll (a) and (b), alpha- and beta-carotene, but increased the concentration of antheraxanthin. A significant decrease was found for the violaxanthin/antheraxanthin ratio following the ozone treatment. The concentration of all the pigments and of nitrogen were significantly related to the age classes, and a similar relationship was found for the light levels, except for antheraxanthin and total carotenoids. The ratio of chlorophyll a/b was only significantly related to the age classes.     

Monitoring of ambient air PCDD/F levels in Portugal

As part of a monitoring program conducted by IDAD--Institute for Environment and Development and supported by regional municipal solid waste (MSW) management authorities, dioxin concentrations in ambient air were measured in three regions of Portugal: Porto, Lisbon and Madeira. These independent studies were performed with the intention of providing data as a basis for the evaluation of potential impacts of the operation of recently built MSW incinerators. Thus, 170 samples were collected in nine different sites from January 1999 till present. The measured levels revealed an extremely variable content of PCDDs/PCDFs depending both on the area and the season of the year. Samples taken in Porto and Lisbon reveal a similar homologue structure even if concentrations measured in the Porto region are significantly greater. Data from Madeira is characteristic of a remote site with some of the congeners concentrations below the detection limit.     

Relationship between foliar injury and changes in antioxidant levels in red and Norway spruce exposed to acidic mists

Elevated levels of total glutathione and enhanced activities of glutathione reductase and ascorbate peroxidase were found in needles of red spruce which had been exposed to acidic mists. Reduced levels of ascorbate were also detected. Such observations suggest that oxidative stress is involved in processes which resist foliar injury caused by acidic misting. Different ionic compositions of the acidic mists applied had pronounced effects on the levels of these antioxidants and the activities of related enzymes. Sulphate was found to be most effective in causing increases in glutathione, while additions of ammonium and/or nitrate mitigated the effects of sulphuric acid. Moreover, it is the composition of ions in the applied mists, rather than the levels of acidity, that determines the extent of the overall response of red spruce. By contrast, although acidic mists caused similar increases in glutathione content of Norway spruce needles, no statistically significant changes of ascorbate or related enzymic activities were found.     

Willow ptarmigan (Lagopus lagopus) as a biomonitor of environmental metal levels in Norway

The purpose of this study was to examine the potential of a native wild bird, Lagopus lagopus, as a monitor of environmental metal levels, in particular with respect to the influence of atmospheric deposition of metals from long-range transport. Specimens of willow ptarmigan were collected from ten different locations in Norway. The concentrations of cadmium, zinc and copper were determined in kidneys of birds from all sites. Mean cadmium levels in adult ptarmigan kidney ranged from 6.6 to 48.5 microg g(-1) (wet weight), with individual concentrations up to 71.0 microg g(-1). These are among the highest cadmium levels reported in wild birds. The kidneys of adult birds contained 3-10 times higher cadmium levels than kidneys from juvenile birds in the same collection area, and most of the high cadmium levels probably reflect natural exposure, rather than atmospheric pollution. Concentrations of elements in kidney tissues were highly correlated with each other.     

Environmental contamination with polychlorinated biphenyls in the area of their former manufacture in Slovakia

Evidently increased environmental pollution as a consequence of the 25-year manufacture of polychlorinated biphenyls (PCBs) in eastern Slovakia was observed. PCB levels determined in ambient air, soil, surface water, bottom sediment, wildlife (fish and game) samples collected in a potentially contaminated area of about 250 km2 (a part of the Michalovce district) were compared with those determined in a control area (Stropkov district). Up to 1700 ng/m3 were found in ambient air in a village close to a manufacturer's dumping site and a highly contaminated manufacturer's effluent canal whereas PCB concentrations in ambient air samples taken in villages in the control area were about 80 ng/m3 only. While soil samples taken from the agricultural fields of the polluted area contained PCBs at levels comparable with soil samples from the control area (about 0.008 mg/kg) much higher values (from 0.4 to 53,000 mg/kg) were determined in soil taken in the vicinity of manufacturer's landfill and storage sites and especially plants preparing asphalted gravel using formerly PCBs in their heat-exchanging systems. The contamination of the Laborec river and large Zemplinska Sirava reservoir is caused by the manufacturer's effluent canal since PCB levels in the canal sediment are still to be found about 3000 mg/kg. While PCB levels in sediment samples from Michalovce watercourses ranged between 1.7 and 6 mg/kg, sediment samples from the control Stropkov district ranged between 0.007 and 0.052 mg/kg only. Fish living in contaminated Michalovce waters contained about hundred times higher PCB levels than those caught in Stropkov ones. Similarly, game animals shot in Michalovce forests contained several times higher levels than those shot in Stropkov ones.     

Mercury contamination in human hair and fish from Cambodia: levels, specific accumulation and risk assessment

Mercury (Hg) concentrations in human hair and fish samples from Phnom Penh, Kien Svay, Tomnup Rolork and Batrong, Cambodia, collected in November 1999 and December 2000 were determined to understand the status of contamination, and age- and sex-dependent accumulation in humans and to assess the intake of mercury via fish consumption. Mercury concentrations in human hair ranged from 0.54 to 190mug/g dry wt. About 3% of the samples contained Hg levels exceeding the no observed adverse effects level (NOAEL) of WHO (50mug/g) and the levels in some hair samples of women also exceeded the NOAEL (10mug/g) associated with fetus neurotoxicity. A weak but significant positive correlation was observed between age and Hg levels in hair of residents. Mercury concentrations in muscle of marine and freshwater fish from Cambodia ranged from <0.01 to 0.96mug/g wet wt. Mercury intake rates were estimated on the basis of the Hg content in fish and daily fish consumption. Three samples of marine fish including sharp-tooth snapper and obtuse barracuda, and one sample of sharp-tooth snapper exceeded the guidelines by US EPA and by Joint FAO/WHO Expert Committee on Food Additives (JECFA), respectively, which indicates that some fish specimens examined (9% and 3% for US EPA and JECFA guidelines, respectively) were hazardous for consumption at the ingestion rate of Cambodian people (32.6g/day). It is suggested that fish is probably the main source of Hg for Cambodian people. However, extremely high Hg concentrations were observed in some individuals and could not be explained by Hg intake from fish consumption, indicating some other contamination sources of Hg in Cambodia.     

Microplastic pollution in freshwater systems in Southeast Asia: contamination levels,sources, and ecological impacts

Environmental Science and Pollution Research - Plastics are synthetic polymers known for their outstanding durability and versatility, and have replaced traditional materials in many applications....     

Human PCDD/PCDF levels near a pentachlorophenol contamination site in Tainan, Taiwan

A pentachlorophenol (PCP) manufacturing plant in southern Taiwan discontinued production in 1989. The site of the abandoned plant was heavily contaminated by PCDD/PCDFs, impurities formed in the PCP production process. Serum samples collected from 27 residents living near the deserted plant were evaluated to determine whether this contamination had associated serum levels of PCDD/PCDFs in local residents. The average level of 17 tested congeners ranged from 556 to 5240 pg/g lipid (mean, 1670 pg/g lipid). The corresponding 2,3,7,8-TCDD toxicity equivalent quotient values calculated by international toxicity equivalent factors (I-TEFs) and those recommended by WHO (WHO-TEFs) were 47.2 pg I-TEQ/g lipid and 53.4 pg WHO-TEQ/g lipid, respectively. Levels in other parts of Taiwan typically range from 15 to 20 pg WHO-TEQ/g lipid; therefore, it is likely that the heavily contaminated plant site caused these unusually high serum levels. The average PCDD/PCDF levels of 29 fish-tissue and nine soil samples collected from the sea reservoir surrounding the abandoned PCP plant were also abnormally high: 8630 pg/g lipid (985 pg WHO-TEQ/g lipid) and 606000 pg/g-sample (922 pg WHO-TEQ/g-sample), respectively. Factor analysis indicated that the congener pattern of human serum samples collected from residents living near the abandoned PCP plant different from samples collected from other areas in Taiwan without known PCDD/PCDF pollution. Similar results were observed for the fish tissue and soil samples. The current study may have discovered a "hot spot" for elevated dioxin human exposure in Taiwan. The preliminary finding has raised a public health concern in the inspected area and requires further investigations to clarify the nature of the contamination and potential impact on the local environment and human health.     

The EU environmental policy context for monitoring for and with raptors in Europe

This paper outlines the importance of the policy context for monitoring with and for raptors, and, conversely, of the importance of such monitoring for policy. It then outlines two key areas of European Union (EU) environmental policy most relevant to monitoring for and with raptors, namely biodiversity policy and pollution policy. For each of the policy areas, the pertinent objectives and actions of the current EU policy are identified, and their relevance for raptor monitoring is discussed. The potential contribution of raptor monitoring to the further development of these policy areas is also addressed.     

Predicting dioxin-like PCBs soil contamination levels using milk of grazing animal as indicator

Dioxin-like PCBs (dl-PCBs) are ubiquitous persistent organic pollutants of recognized negative effects on human health. Assessing highly polluted areas should be an important public health issue. This study proposes to use the milk of grazing animals as a bioindicator of dl-PCB contamination in the environment. The hypothesis is that milk concentration of dl-PCBs are related to soil concentrations of these compounds, and that soils are generally reflective of a larger environmental issue of dl-PCB contamination. In this study, we evaluate the possibility of predicting soil concentrations using milk of sheep, cows and buffalos in a spatial model. For this purpose, samples of soil and milk collected in Campania (Italy) were introduced in a GIS platform to perform geostatistical analysis for building a simple predictive model. The ordinary least squares regressions (OLS) showed a statistically significant correlation (p < 0.05) between soil and milk contamination. However, this relationship was spatially variable. Thus, a geographically weighted regression (GWR) was performed, obtaining R² values of 0.91, 0.77 and 0.66 for sheep’s, buffalo’s and cow’s milk respectively. Assessed the mathematical relationships between the variables, new data was introduced to evaluate the performance of the model. Predictions of soil contamination with dl-PCBs using sheep’s, cow’s and buffalo’s milk showed a mean error of 23%, 25% and 36% respectively. According to these results the sheep’s milk can be considered the best bioindicator of dl-PCBs contamination among the three species. The results of this project evidence the potentialities of the proposed approach to assess bioindicator performance in a spatial predictive model.     

Monitoring historical changes in soil and atmospheric trace metal levels by dendrochemical analysis

The use of dendrochemistry for monitoring historical changes in trace metal deposition and mobilisation of metals in soils is evaluated. In experimental studies, mobilisation of trace metals in surface soil following deliberate acidification was recorded in sugar maple (Acer saccharum) tree-rings with minimal lateral movement between rings. Furthermore, positive correlations between wood (3 year section 1993-95) and foliar chemistry (mean concentration 1993-95) were found for Cd and Zn, but not for Cu and Ni, showing that mobility up the tree bole differs between metals. Even so, substantial lateral movement of elements between rings occurs in some species. Stable Pb isotope ratios in tree-rings were used to show that sacred fir (Abies religeosa) is not a useful monitor of Pb deposition because Pb accumulates in the heartwood. Numerous sophisticated analytical techniques are now used in dendrochemical studies, including laser ablation sampling in conjunction with inductively coupled plasma mass spectrometry that enable the multi-element analysis of extremely small tree-rings with low detection limits. Clearly, not all tree species are suitable for dendrochemical studies, but if careful sampling strategies are used and suitable tree species are chosen, the chemical analysis of tree-rings can provide information concerning historical changes in soil and atmospheric trace metal levels unavailable from any other source.     

Status of sulphur in the foliage of Norway spruce (Picea abies (L.) Karst.) in relation to the mode of contamination

For decades, trees have been exposed to atmospheric S pollution (acid rains). They can thus fulfil their S requirements not only via the roots, but also via their needles. However, whether leaf-absorbed S has a different fate from that of root-absorbed S, or may be toxic to the plant, remains uncertain. Norway spruce trees have been contaminated with (35)SO(4)(2-) either via a nutrient solution, or via a spray, and their (35)S distribution has been analysed. In the case of foliar contamination, a high percentage of (35)S(-) was present in the form of SO(4)(2-), both on the surface and inside the youngest needles. In the case of root contamination, the (35)S of the youngest leaves was mainly incorporated into insoluble organic compounds. Older needles showed a different S distribution.     

Growth and trace metal accumulation of two Salix clones on sediment-derived soils with increasing contamination levels

The growth and metal uptake of two willow clones (Salix fragilis 'Belgisch Rood' and Salix viminalis 'Aage') was evaluated in a greenhouse pot experiment with six sediment-derived soils with increasing field Cd levels (0.9-41.4 mg kg-1). Metal concentrations of eight elements were measured in roots, stems and leaves and correlated to total and soil water metal concentrations. Dry weight root biomass, number of leaves and shoot length were measured to identify eventual negative responses of the trees. No growth inhibition was observed for both clones for any of the treatments (max. 41.4 mg kg-1 Cd, 1914 mg kg-1 Cr, 2422 mg kg-1 Zn, 655 mg kg-1 Pb), allowing their use for phytoextraction on a broad range of contaminated sediments. However, dry weight root biomass and total shoot length were significantly lower for S. viminalis compared to S. fragilis for all treatments. Willow foliar Cd concentrations were strongly correlated with soil and soil water Cd concentrations. Both clones exhibited high accumulation levels of Cd and Zn in aboveground plant parts, making them suitable subjects for phytoextraction research. Cu, Cr, Pb, Fe, Mn and Ni were found mainly in the roots. Bioconcentration factors of Cd and Zn in the leaves were highest for the treatments with the lowest soil Cd and Zn concentration.     

Crown condition of Norway spruce in relation to sulphur and nitrogen deposition and soil properties in southeast Norway

Atmospheric deposition of sulphur and nitrogen compounds may lead to enhanced leaching of base cations, accumulation of nitrogen in organic matter, lowered pH and increased concentration of toxic aluminium in soil, which in turn may affect the vitality of forest trees. A general monitoring of forest condition has been initiated in many European countries, partly in order to reveal stresses caused by acidification. However, forest condition is also affected by many other factors. This paper examines a seven-year series of crown-condition data from Local County Monitoring Plots in Norway spruce stands in Norway. Average, time trend and lability variables were calculated for crown density and crown colour for each plot. Wet deposition of sulphate, ammonium and nitrate for each plot were estimated using data from the national air and precipitation monitoring programmes. Soil data are based on soil sampling within the plots. The analysis gave no evident support for the hypothesized negative effect on crown condition from sulphur and nitrogen deposition and related alterations in soil.