In order to investigate the regional background concentration levels of mercury (Hg), measurements were routinely recorded on An-Myun Island off the coast of Korea (December 2004 to April 2006). The mean concentration of Hg computed from the entire measurement period was 4.61 ± 2.21 ng m-³ with a range of 0.10-25.4 ng m-³ (N = 10,485). Using these data, we inspected various aspects of Hg behavior from the relatively remote island of An-Myun in Korea. Inspection of the seasonal patterns of Hg indicated that its concentration levels generally peaked in spring, while reached a minimum in summer. The summertime deficiency of Hg along with the lack of diurnal variation suggests that the environmental behavior of Hg at the study site was strongly suppressed by heavy precipitation during specific period. The diurnal variations of Hg, typically characterized by a relative daytime dominance, are distinguishable between seasons so that such patterns disappear during the summer. The results of our analysis, when inspected in terms of long-range transport of airborne pollutants, imply that Hg concentration levels can be affected intensively by trans-boundary input processes over certain period of time. Its springtime dominance hence suggests the combined effects of various local source processes and the meteorological conditions favorable for the massive air mass transport phenomenon (such as Asian Dust storms) during that time period.

The effects of ozone in four maple species, Acer campestre, A. opalus subsp. granatense, A. monspessulanum and A. pseudoplatanus were studied in OTC under two different experimental conditions: in charcoal filtered air (CF), and in non filtered air plus 30 ppb ozone (NF+30). The four species of maple showed contrasting sensitivity to ozone as demonstrated by visible injury development, gas exchange and chlorophyll a fluorescence, and growth measurements. Plant injury index (i.e. a combination of percentage of injured leaves and leaf surface affected) was more consistently related with physiological measurements than the onset of first symptom of visible injury. Differences in ozone sensitivity among species may be partly related to higher stomatal conductances in A. opalus and A. pseudoplatanus. In these two species, ozone produced significant reductions in CO₂ assimilation under saturating light conditions (A sat), stomatal conductance (g s), transpiration rate (T r) and Water Use Efficiency (WUE) (the latter also significantly declined in A. campestre) towards the end of summer, while intercellular CO₂ concentrations (C i) increased significantly. In asymptomatic leaves of A. opalus, neither stomatal limitation nor photoinhibitory damage (F v/F m) could explain the observed decline of A sat, and photosynthesis was down regulated by reducing the proportion of absorbed energy used in photochemistry (Φ PSII) at expenses of the energy dispersed non-photochemically (NPQ). Leaf N content also declined significantly in A. pseudoplatanus. Plants exposed to ozone showed a tendency to decrease growth, but it was not significant within the exposure period for any of the four species. The most sensitive species were A. opalus and A. pseudoplatanus, while the species with the smallest and more coriaceous leaves, A. monspessulanum, was the most resistant.

We investigated the Austrian national greenhouse gas emission inventory to review the reliability and usability of such inventories. The overall uncertainty of the inventory (95% confidence interval) is just over 10% of total emissions, with nitrous oxide (N₂O) from soils clearly providing the largest impact. Trend uncertainty - the difference between 2 years - is only about five percentage points, as important sources like soil N₂O are not expected to show different behavior between the years and thus exhibit a high covariance. The result is very typical for industrialized countries - subjective decisions by individuals during uncertainty assessment are responsible for most of the discrepancies among countries. Thus, uncertainty assessment cannot help to evaluate whether emission targets have been met. Instead, a more rigid emission accounting system that allows little individual flexibility is proposed to provide harmonized evaluation uninfluenced by the respective targets. Such an accounting system may increase uncertainty in terms of greenhouse gas fluxes to the atmosphere. More importantly, however, it will decrease uncertainty in intercountry comparisons and thus allow for fair burden sharing. Setting of post-Kyoto emission targets will require the independent evaluation of achievements. This can partly be achieved by the validation of emission inventories and thorough uncertainty assessment.

Lygeum spartum, Zygophyllum fabago and Piptatherum miliaceum are typical plant species that grow in mine tailings in semiarid Mediterranean areas. The aim of this work was to investigate metal uptake of these species growing on neutral mine tailings under controlled conditions and their response to fertilizer additions. A neutral mine tailing (pH of soil solution of 7.1-7.2) with high total metal concentrations (9,100 and 5,200 mg kg-¹ Zn and Pb, respectively) from Southern Spain was used. Soluble Zn and Pb were low (0.5 and <0.1 mg l-¹, respectively) but the major cations and anions reached relatively high levels (e.g. 2,600 and 1,400 mg l-¹ Cl and Na). Fertilization caused a significant increase of the plant weight for the three species and decreased metal accumulation with the exception of Cd. Roots accumulated much higher metal concentrations for the three plants than shoots, except Cd in L. spartum. Shoot concentrations for the three plants were 3-14 mg kg-¹ Cd, 150-300 mg kg-¹ Zn, 4-11 mg kg-¹ Cu, and 1-10 mg kg-¹ As, and 6-110 mg kg-¹ Pb. The results indicate that neutral pH mine tailings present a suitable substrate for establishment of these native plants species and fertilizer favors this establishment. Metal accumulation in plants is relatively low despite high total soil concentrations.

Former mining activities lasting 140 years in the Ducktown Mining District, Tennessee, USA, has contaminated the streams draining the district with acid-mine drainage (AMD). North Potato Creek and its major tributary, Burra Burra Creek, are two of the most heavily AMD-impacted streams in the district. The removal of dissolved metals from the water in these creeks is largely attributable to the sorption of Cu, Zn, Co, Al, and Mn on suspended hydroxide precipitates of Fe. The fraction of trace metals remaining in solution decreases with increasing pH in the sequence Pb < Cu < Zn < Co. The concentration of Fe in solution also decreases with increasing pH due to the formation of ferric hydroxide precipitates which accounted for up to 81.4% by weight of the total suspended sediment. The concentration of suspended sediment substantially decreases as the water of North Potato Creek flows through a large settling basin, where 1.3 (±0.3) x 10⁶ kg/year of trace-metal-laden suspended sediment would be annually deposited. In spite of this attempt to purify it, the water discharged into the river is acidic (pH 3.6) and still contains high concentrations of dissolved trace metals, which would resorb on to suspended sediment and be ultimately transported to a downstream reservoir, Ocoee No. 3 Lake.

An important component of monitoring pollution of urban road-deposited sediment (RDS) is an understanding of the temporal variability in its composition and physical characteristics. This study set out to determine what the monthly variability in metal concentrations, organic matter content, grain-size and grain-size fraction metal-loadings are in inner city sites in Manchester, northwest England. The results show that there is significant temporal variability in metal (Pb, Zn, Fe, Mn) concentration in RDS from inner city Manchester. There was no significant temporal variability in grain-size characteristics or organic matter content, indicting that these metal variations were the result of variation in sources and accumulation processes. Pb and Zn displayed local variability, suggesting local controls on variability, whereas Fe and Mn displayed consistent variability across all sites, suggesting a common, larger-scale control on variability. The finest grain-size fraction (<63 μm) contained the highest Pb, Cu and Zn concentrations, but for the case of Fe and Mn, the coarser fractions (>300 μm) commonly contained the highest concentrations, again suggesting differing controls. For all metals, due to the weight percent dominance of the coarser fractions, the dominant loading of metals is in the coarser fractions. This has implications on management strategies, via street sweeping and the subsequent waste disposal, and on the modelling of the input of RDS and associated metals into surface waterways. The recognition of significant temporal variability of metal concentrations in RDS, independent of grain-size changes, implies that the monitoring of urban road sediment pollution will require not just consideration of spatial variability, but the design of schemes that will capture temporal variability also.

Heavy metal phytoextraction is a soil remediation technique, which makes use of plants in removing contamination from soil. The plants must thus be tolerant to heavy metals, adaptable to soil and climate characteristics, and able to take up large amounts of heavy metals. Most of the high biomass productive plants such as, maize, oat and sunflower are plants, which do not grow in cold climates or need intensive care. In this study three “weed” plants, Borago officinalis; Sinapis alba L. and Phacelia boratus were investigated for their ability to tolerate and accumulate high amounts of Cd and Pb. Pot experiments were performed with soil containing Cd and Pb at concentrations of up to 180 mg kg⁻¹ and 2,400 mg kg⁻¹ respectively. All three plants showed high levels of tolerance. Borago officinalis; and Sinapis alba L. accumulated 109 mg kg⁻¹ and 123 mg kg⁻¹ Cd, respectively at the highest Cd spiked soil concentration. Phacelia boratus reached a Cd concentration of 42 mg kg⁻¹ at a Cd soil concentration of 100 mg kg⁻¹. In the case of Pb, B. officinalis and S. alba L. displayed Pb concentrations of 25 mg kg⁻¹ and 29 mg kg⁻¹, respectively at the highest Pb spiked soil concentration. Although the Pb uptake in P. boratus reached up to 57 mg kg⁻¹ at a Pb spiked soil concentration of 1,200 mg kg⁻¹, it is not suitable for phytoextraction because of its too low biomass.

The rapid biodegradation of metsulfuron-methyl in contaminated soil was studied in this paper. The wheat (Triticum aestivum L.) rhizosphere was well simulated by setting up a hydroponic system that allowed the aseptic wheat root exudates flow onto columns containing soil previously contaminated with metsulfuron-methyl. The root-colonizing strain Penicillium sp. containing highly effective degrading plasmid on metsulfuron-methyl was inoculated in the soil, with the bulk and sterile ones as control. In soil from columns that received root exudates from a planted (versus an unplanted) apparatus, there was a significant increase in the growth of the tolerant fungi and the degradation of metsulfuron-methyl. On the other hand, the inoculation of Penicillium sp. also notably enhanced the degradation of the target herbicide. The extent of stimulation was more than twice of that measured in bulk soil. The fastest rate of disappearance of the xenobiotic occurred in the amended inoculated microcosms with 8.6 days of the half-life. The main types of low molecular weight organic acids and amino acids in the root exudates was determined to be oxalic acid, succinic acid and threonine, alanine, proline, methionine, lysine, isoleucine and leucine. What's more, by means of applying metsulfuron-methyl once again, the acclimated soil microorganisms with Penicillium sp. inoculation could sustainable rapid degrade metsulfuron-methyl. The results show that inoculation of the root-colonizing Penicillium sp. in wheat rhizosphere may be an effective approach for the rapid detoxification of soil metsulfuron-methyl contamination.

The use of numerical modeling in oil spill incidents is a well established technique that has proven to provide cost-effective and reasonable estimates of oil surface drift. Good predictability of such models depends highly on the quality of the input data of the incident and on the model calibration effort. This paper presents the results of simulating oil spillage trajectory in the Arabian (Persian) Gulf. The study employed a 3-D rectilinear hydrodynamic model combined with oil spill model. Typical representative environmental conditions of the Arabian Gulf were first setup into a hydrodynamic circulation model using data from various sources. The performance of the hydrodynamic model was then tested against measurements of tidal fluctuation and sea currents at selected locations. The spill analysis model was setup using the flow field produced from the hydrodynamic simulation and its performance was further validated against documented events of Al-Ahmadi historical oil spill crisis in the Gulf. The comparison of the actual and simulated oil spill drift was found reasonably acceptable allowing for further application in risk assessment studies in UAE Coastal water and in the entire Arabian Gulf as well.

A multi-media monitoring field investigation, which included atmospheric, road sediment and soil samples, was carried out at two highway study sites to identify past and present Pb sources. Past Pb anthropogenic sources such as paint and leaded gasoline were linked to significant Pb accumulation in roadside soils at both sites through Pb isotopic analyses. This was achieved by identifying the distinct Pb isotopic composition in older versus newer Pb accumulation at different depths across the soil profile. Older Pb accumulations exhibited lower ²⁰⁶Pb/²⁰⁷Pb isotopic ratios, consistent with Canadian Pb-bearing ores, whereas newer Pb accumulations reflected a mixture of the ²⁰⁶Pb/²⁰⁷Pb ratios of road sediment samples, with the Pb isotopic signature of uncontaminated soil. Isotopic analyses were also helpful in identifying road sediment as an important current source of Pb in roadside soils, by comparing the isotopic signatures derived from road sediment and atmospheric dustfall. The known association of Pb with anthropogenic sources was used to indirectly relate other metals (Cu, Mn, Zn) to the same source by the Enrichment Ratio method. Significant positive correlations at the 90-95% confidence level were found between Cu, Zn and Pb Enrichment Ratios in roadside and dust deposition samples. Weaker correlations were found between Mn and Pb, at the highway study site with the least amount of traffic. However, correlations between these two metals were significant at the 90% confidence level for the busier highway site highlighting Mn potential anthropogenic source. An isotopic tracer study is suggested to further investigate the process of Mn redistribution in the environment due to exhaust fuel emissions. More research is needed regarding the potential impact from using a Mn-based fuel additive.