The interaction between fluvially transported, metal contaminated peat particulates and acidic waters draining peatland catchments has received limited attention. Potential in-stream processing of sediment-associated metals in acidic stream water was investigated in laboratory based mixing experiments, designed to represent conditions of fluvial sediment transport in a highly contaminated and severely eroding peatland catchment in the Peak District (UK). Over the initial 20 min of the first experiment, stream water Cr and Zn concentrations increased by at least an order-of-magnitude and remained elevated for the full duration (24 h) of the experiment. Stream water As, Mo, Pb, Ti and V concentrations increased between 43% (As) and 440% (V) over the first hour of the experiment. After 24 h most of the metals appeared to have reached equilibrium in the water column. Results of the second experiment revealed that when the concentration of metal contaminated peat particulates is increased, there is an associated increase in the stream water As, Cr, Mo, Pb, Ti, V and Zn concentrations. The experimental data suggest that As, Cr, Mo, Pb, Ti, V and Zn are liable to desorption from metal contaminated peat into acidic stream water. The solubilisation of contaminated peat particulates may also contribute to elevated stream water metal concentrations. The laboratory based approach used in this study may indicate that when there is erosion of metal contaminated peat into acidic fluvial systems there is a concomitant increase in dissolved metal levels, especially when suspended sediment concentrations are high. Further laboratory and field based experiments are required to evaluate the relative importance of physical and chemical processes in the interaction between contaminated peat particulates and stream water in peatland fluvial systems.

Source apportionment analysis was used to identify the factors contributing to atmospheric pollution at a monitoring location in the Southeast of Spain, a well documented area with an arid climate and high insolation favouring two sources of particulate matter: secondary transformation in the atmosphere and resuspension of crustal dry soils to the air. These conditions are further complicated by numerous industrial facilities in the area of the historical city of Cartagena. This paper describes the air quality of an area which includes a zinc metallurgical industry, a petrochemical factory, an oil power station, a shipyard and natural phenomena including African dust transport and resuspension of regional and/or local crustal materials. Major and trace element concentrations in PM10 and PM2.5 were determined at two monitoring stations in Cartagena (one PM10 sampler located at a traffic hotspot and the PM2.5 sampler at a suburban station), during 2004 and 2005. Results showed that in the PM10 fraction, the zinc metallurgical activity was linked to high levels of Cd, Zn and Pb; shipyard emission was associated with high levels of Cr and Ni; and high Ni and V levels were associated with the secondary aerosol indicating the contribution from oil combustion (oil-fired power station or petrochemical facilities). In the PM2.5 size fraction, the zinc source is defined by Zn and Pb; V, Ni and As appear with the oil combustion emissions. In contrast to PM10, shipyard activity is not consistently defined. Consistent sources found in both size fractions include crustal materials and traffic emissions.

Phytoremediation, which mainly employs hyperaccumulators to remove heavy metals from contaminated soils, is receiving more attention world-wide. The identification of hyperaccumulators is still a key step for phytoremediation. This research is devoted to identify some plants with hyperaccumulative characteristics from weed species. In a pot culture experiment, the hyperaccumulative characteristics of 13 weed species in 11 families to Cd, Pb, Cu and Zn were examined. The result showed that Taraxacum mongolicum and Rorippa globosa indicated some Cd hyperaccumulative properties. In a sample-analysis experiment conducted in a Pb-Zn mining area, T. mongolicum and R. globosa also displayed the same hyperaccumulative characteristics. However, in a concentration gradient experiment, Cd content in shoot of T. mongolicum was not higher than 100 mg/kg (DW, dry weight), the minimum Cd concentration for a Cd-hyperaccumulator in any treatment. The concentration of Cd in the stems and leaves of R. globosa were greater than 100 mg/kg, under the conditions of the soils spiked with 25 and 50 mg/kg Cd. The Cd accumulation factors and translocation factors in the shoots of R. globosa were higher than 1 too, and the plant biomasses did not decrease significantly (p < 0.05) compared with the control. Thus, we conclude that only R. globosa showed the whole Cd-hyperaccumulator properties, which is a Cd-hyperaccumulator.

An elevated concentration of uranium in the water of some springs in the Permo-Triassic sedimentary rocks of the Visok region, south-eastern slopes of the Stara Planina, eastern Serbia, is interpreted based on geological, hydrogeological and hydrochemical data. Uranium concentration in groundwater was first examined whilst exploring for uranium minerals as an energy resource. The purpose of a later hydrogeological investigation was assessment of a safe drinking water supply to a planned ski-centre hotel. The maximum contaminant level for uranium, recommended by the World Health Organization (WHO), is 15 μg/L. This work reviews and interprets the naturally elevated uranium in springs from the Permo-Triassic sediments of Visok, focusing on geological, hydrogeological, hydrogeochemical and other factors of uranium contamination. Uranium distribution in groundwater from Permo-Triassic aquifers was studied by taking groundwater, spring sediment and rock samples. The varied mobility of uranium depends largely on lithology, which also controls the chemistry of groundwater. The investigation results have shown that sulfate-calcium groundwater is a suitable facilitator of uranium mobility with a high migration coefficient of 0.77. Uranium concentrations in this water were up to 41 μg/L, with a Sa/Sr mass ratio of around 20, and a mineral content of about 0.5 g/L. The hydrochemistry was characteristically transitional Eh and pH neutral. Elevated uranium in groundwater has been reported globally and may be compared.

Intensive cultivation of fen peat soils (Eutric Histosols) for agricultural purposes, started in Europe about 250 years ago, resulting in decreased soil fertility, increased oxidation of peat and corresponding CO₂-emissions to the atmosphere, nutrient transfer to aquatic ecosystems and losses in the total area of the former native wetlands. To prevent these negative environmental effects set-aside programs and rewetting measures were promoted in recent years. Literature results and practical experiences showed that large scale rewetting of intensively used agricultural Histosols may result in the mobilisation of phosphorus (P), its transport to adjacent surface waters and an accelerated eutrophication risk. The paper summarises results from an international European Community sponsored research project and demonstrates how results obtained at different scales and from different scientific disciplines were compiled to derive a strategy to carry out rewetting measures. A decision support system (DSS) for a hydrologically sensitive area in the Droemling catchment in north-eastern Germany was developed and is presented as a tool to regulate rewetting in order to control P release. It is demonstrated that additional laboratory experiments to identify essential processes of P release during rewetting and the site-specific management of the water table, the involvement of specific knowledge and experience of the stakeholders are necessary to develop an applicable DSS. The presented DSS is practically used to prevent freshwater resources from diffuse P pollution.

Meteorological factors affecting concentration of dissolved inorganic nitrogen in rain were examined. Rain samples were collected on an event basis from a location 100 km east of the Los Angeles Basin. Analysis of the data demonstrated a double decay function where small increases in rain volume resulted in large decreases in nitrogen concentration. In separate time series collections of individual storms, storm wind direction also influenced nitrogen concentrations

In recent years, arsenic (As) has received increased attention as humans may be exposed to it through occupational and environmental exposure. Tobacco (Nicotiana tabacum L.) like other crops can uptake this element from the soil, which may lead to human exposure. Here, we report on a survey on arsenic in cured or processed tobacco leaves obtained from Africa, Asia, Europe, South and North America. A total of 1,431 leaf samples of flue-cured, burley, and Oriental tobaccos were obtained from various sampling locations during 2002 to 2004. Arsenic concentration in the samples averaged 0.4 ± 0.6 μg g⁻¹ as determined by inductively coupled plasma-mass spectrometry. Recorded values from most samples showed that concentrations of arsenic were usually found at the lower end of the distribution. Significant differences were found among tobacco types, sampling locations, and crop years. Arsenic concentrations were rather low in the majority of regions investigated, which is compatible with data from the literature. However, sample size was small and sampling geographically restricted. Our results would need to be validated with a larger dataset.

Fluoride, a common phytotoxic air, water and soil pollutant is commonly released to the environment by a number of industrial processes. Agricultural soils high in fluoride are common due to long term accumulation of fluoride from multi-sources and extensive application of phosphate fertilizers. The effect of sodium fluoride (0, 50,100,150 mM) on growth, pigments content, changes in biochemical parameters, along with fluoride and other ions accumulation was investigated in Salicornia brachiata grown in solution cultures under controlled conditions. With fluoride treatment growth as fresh or dry mass accumulation increased marginally. However, higher concentrations decreased the biomass and shoot tip became blunt; margin of the shoot changed its colour to reddish brown and developed necrotic spots. Photosynthetic pigments (chlorophylls and carotenoids) content decreased, while, anthocyanin content increased significantly with fluoride treatment. Peroxidase (POX), superoxide dismutase (SOD), ATPase and acid phosphate activities were negatively regulated. In addition F-, Na⁺, Mn²⁺ and Fe²⁺ ions concentration increased while, K⁺, Ca²⁺ and Mg²⁺ contents decreased with fluoride treatment. To our knowledge this is the first report on fluoride tolerance in a marshy halophytes using as high as 150 mM concentration and the results suggest that S. brachiata is a moderately fluoride tolerant annual halophyte and may be useful to vegetate the fluoride contaminated marshy lands.

Soil and water samples were analysed for trace metals and As in two watercourses and 14 sampling plots in a salt marsh polluted by mine wastes in SE Spain. Groundwater levels, soil pH and Eh were measured 'in situ' for a 12-month period in each sampling plot, and total calcium carbonate was also determined. Low concentrations of soluble metals (maximum Mn 1.089 mg L-¹ and maximum Zn 0.553 mg L-¹) were found in the watercourses. However, total metal contents were extremely high in the soils of a zone of the salt marsh (maximum 1,933 mg kg-¹ of Mn, 62,280 mg kg-¹ of Zn, 16,845 mg kg-¹ of Pb, 77 mg kg-¹ of Cd, 418 mg kg-¹ of Cu and 725 mg kg-¹ of As), and soluble metals in the pore water reached 38.7 mg L-¹ for Zn, 3.15 mg L-¹ for Pb, 48.0 mg L-¹ for Mn, 0.61 mg L-¹ for Cd and 0.29 mg L-¹ for As. Variable concentrations with depth indicate a possible re-mobilisation of the metals, which could be related to spatial and temporal variations of water table level, pH and Eh and to the presence of calcium carbonate. A tendency for the Eh to decrease in the warmest months and to increase in the coldest ones was found, especially, in plots that received water with a high content of dissolved organic carbon. Hence, the existence of nutrient effluent-enriched water may modify the physical-chemical conditions of the soil-water system and influence metal mobility.

POPs are still a priority environmental problem, but can be used as a scientific tool for understanding the distribution phenomena. Both high mountains and polar areas are seen as priority zones for contamination studies. In this context, two altitudinal series of soil samples were analysed for several classes of Persistent Organic Pollutants (PCBs, DDTs, HCHs, HCB and chlordane). Two transects were carried out - one in the Peruvian Andes (Cordillera Blanca) and the other in the Italian Alps (Mount Legnone). In these two areas, POP composition and levels both gave different results, linked to regional emission history. The Italian samples were characterized by high levels of industrial type compounds, and by surprisingly high DDT contamination, due to a defined consistent local source in Northern Italy. The Peruvian samples, on the other hand, were characterized by generally low POP levels with relatively high DDT contamination. The concentration increase in line with elevation was evident only in the Italian transect, where higher precipitation intensities and an increasingly higher precipitation gradient in accordance with altitude was found present. Precipitations are considered a key factor for enhancing the condensation effect at high altitudes and for reducing summer revolatilisation, as they lower soil temperature. In the Italian altitudinal gradient, evidence of fractionation processes, with a shift of the PCB composition towards less chlorinated congeners, and a vegetation effect with a mean woodland/grassland enrichment factor between 2 and 4 were also observed.