Temperature inversion characteristics in relation to synoptic circulation above Athens,Greece

In this paper, the characteristic properties of inversions formed inside the lower boundary layer over Athens, Greece, were studied using 35-year radiosonde measurements of temperature, humidity, and atmospheric pressure. The analysis revealed that the inversion parameters demonstrate considerable seasonal variation. Specifically, inversions associated with weak anticyclonic conditions are more frequent during the winter and summer months, while during spring, weak lows are more probable to produce inversions. Some theoretically expected associations between synoptic circulation patterns and certain inversion parameters were also identified.     

Environmental Damage,Abandoned Treaties,and Fossil-Fuel Dependence: The Coming Costs of Oil-and-Gas Exploration in the “1002 Area” of the Arctic National Wildlife Refuge

Contrary to claims from American politicians, lobbyists, and oil and gas executives, allowing energy development in the Alaskan Arctic National Wildlife Refuge (ANWR) will harm the environment, compromise international law, erode the social significance of wilderness protection, and ultimately fail to␣increase the energy security of the United States. After exploring a brief history of the ANWR controversy, this piece argues that the operation of oil and gas refineries in ANWR will release discharged solids, drilling waste, and dirty diesel fuel into the ecosystem’s food-chain, as they have from oil operations in Prudhoe Bay. Less obvious but equally important, oil and gas exploration in ANWR will violate a number of international treaties on biodiversity protection. In the end, development in ANWR will threaten the concept of wilderness protection, and will do little to end US dependence on foreign sources of energy. About the Author: Benjamin K. Sovacool is a doctoral candidate in the Department of Science and Technology Studies at the Virginia Polytechnic Institute & State University in Blacksburg, Virginia. He works as a research analyst for the Consortium on Energy Restructuring and is a Senior Research Fellow for the Virginia Center for Coal and Energy Research. He also just completed a Graduate Fellowship in Energy Policy at the Oak Ridge National Laboratory in Oak Ridge, Tennessee. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

The use of amino compounds for binding 2,4,6-trinitrotoluene in water

Sites polluted with 2,4,6-trinitrotoluene (TNT) constitute a worldwide problem. In this work, chemical reactions for binding TNT to amino-compounds are proposed as an initial step for developing new remediation techniques to clean-up groundwater and soils contaminated with TNT. Indeed, addition of aniline and an amino acid-like cysteine caused a decrease in free TNT of 86% and 68-100%, respectively. Using 13C-NMR spectroscopy, it was shown that TNT chemically forms a Meisenheimer complex with cysteine and aniline in 1/1 (by vol.) H2O/d6-acetone.     

Reactive transport modeling of processes controlling the distribution and natural attenuation of phenolic compounds in a deep sandstone aquifer

Reactive solute transport modeling was utilized to evaluate the potential for natural attenuation of a contaminant plume containing phenolic compounds at a chemical producer in the West Midlands, UK. The reactive transport simulations consider microbially mediated biodegradation of the phenolic compounds (phenols, cresols, and xylenols) by multiple electron acceptors. Inorganic reactions including hydrolysis, aqueous complexation, dissolution of primary minerals, formation of secondary mineral phases, and ion exchange are considered. One-dimensional (1D) and three-dimensional (3D) simulations were conducted. Mass balance calculations indicate that biodegradation in the saturated zone has degraded approximately 1-5% of the organic contaminant plume over a time period of 47 years. Simulations indicate that denitrification is the most significant degradation process, accounting for approximately 50% of the organic contaminant removal, followed by sulfate reduction and fermentation reactions, each contributing 15-20%. Aerobic respiration accounts for less than 10% of the observed contaminant removal in the saturated zone. Although concentrations of Fe(III) and Mn(IV) mineral phases are high in the aquifer sediment, reductive dissolution is limited, producing only 5% of the observed mass loss. Mass balance calculations suggest that no more than 20-25% of the observed total inorganic carbon (TIC) was generated from biodegradation reactions in the saturated zone. Simulations indicate that aerobic biodegradation in the unsaturated zone, before the contaminant entered the aquifer, may have produced the majority of the TIC observed in the plume. Because long-term degradation is limited to processes within the saturated zone, use of observed TIC concentrations to predict the future natural attenuation may overestimate contaminant degradation by a factor of 4-5.     

Impact of repeated application on the binding and persistence of [14C]-DDT and [14C]-HCH in a tropical soil

An Indian sandy loam soil was initially treated with 1 kg a.i. ha(-1) of either [(14)C]-p,p'-DDT or [(14)C]-gamma-HCH during winter. DDT concentration after 30 days declined to 75.3%, which included 2.1% soil-bound residues. After 150 days, DDT levels further decreased to 42.4% with a concomitant increase in bound residues amounting to 5.9%. Identical treatment with HCH caused the residue levels to be reduced to 67.4 and 23.6%, after 30 and 150 days, respectively. During this period, the soil-bound residues of HCH increased from 5.2 to 12.8%. Repeat application to pre-treated soils in summer and subsequent field exposure for 30 days reduced the concentration of DDT to 52.1% and that of HCH to 42.4% of the total concentration following the second treatment. In parallel control experiments, which received only a single treatment, DDT levels declined to 61.3%, while HCH slumped to 45.3%, indicating a slower dissipation rate than in the corresponding repeated treatments. In repeat experiments, the soil-bound residues of DDT and HCH showed only a 1.07 to 1.08-fold increase in 30 days, as compared to three to ten-times increase in the control experiments. The results amply demonstrate that pre-treatment of tropical soils with DDT or HCH enhances their rate of dissipation and significantly reduce the formation of their soil-bound residues.     

Studies on water hyacinth as a biological filtre for treating contaminants from agricultural wastes and industrial effluents

The aquatic weed--water hyacinth [Eichhornia crassipes (Mart) Solms] showed a remarkable capacity to withstand the effects of pH changes ranging from 5 to 8 in the aquatic environment. Growth continued to be normal except when placed for longer periods in medium containing iron ions at pH 3.3. The ability of this plant to neutralize some very acid solutions of heavy metals such as salts of copper, cadmium and zinc individually and in combinations, is being reported. Plants placed in pure acid and alkali solutions were also able to neutralize the medium. Calcium appears to play an important role in the mechanism involved in the adaptability of these plants to such environments.     

It’s All in the Numbers: Acreage Tallies and Environmental Program Evaluation

Increasingly, performance measurement is being used to hold federal agencies accountable, represent environmental progress, and evaluate the effectiveness of environmental programs. The need to track measurable outputs has created a tendency to present programmatic progress solely by quantifiable data, despite the inherent complexity of natural resource management. Wetlands and fire management programs are two specific environmental arenas that have come to overemphasize the tracking of acreage numbers to validate existing policy direction. In both of these arenas, we find the definition and categorization of "countable" acres to be inconsistent and unreliable. We explore this systemic flaw for both wetlands and fire programs and describe its implications for environmental policy and natural resource management more broadly. We conclude with recommendations for improved performance measurement in these arenas.     

Characterizing spatial structure of sediment E. coli populations to inform sampling design

Escherichia coli can persist in streambed sediments and influence water quality monitoring programs through their resuspension into overlying waters. This study examined the spatial patterns in E. coli concentration and population structure within streambed morphological features during baseflow and following stormflow to inform sampling strategies for representative characterization of E. coli populations within a stream reach. E. coli concentrations in bed sediments were significantly different (p?=?0.002) among monitoring sites during baseflow, and significant interactive effects (p?=?0.002) occurred among monitoring sites and morphological features following stormflow. Least absolute shrinkage and selection operator (LASSO) regression revealed that water velocity and effective particle size (D ₁₀) explained E. coli concentration during baseflow, whereas sediment organic carbon, water velocity and median particle diameter (D ₅₀) were important explanatory variables following stormflow. Principle Coordinate Analysis illustrated the site-scale differences in sediment E. coli populations between disconnected stream segments. Also, E. coli populations were similar among depositional features within a reach, but differed in relation to high velocity features (e.g., riffles). Canonical correspondence analysis resolved that E. coli population structure was primarily explained by spatial (26.9–31.7 %) over environmental variables (9.2–13.1 %). Spatial autocorrelation existed among monitoring sites and morphological features for both sampling events, and gradients in mean particle diameter and water velocity influenced E. coli population structure for the baseflow and stormflow sampling events, respectively. Representative characterization of streambed E. coli requires sampling of depositional and high velocity environments to accommodate strain selectivity among these features owing to sediment and water velocity heterogeneity.     

Toxicities and tolerances of Cd, Cu, Pb and Zn in a primary producer (Isochrysis galbana) and in a primary consumer (Perna viridis)

Studies on toxicities and tolerances of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) in the brown alga Isochrysis galbana and in the green-lipped mussel Perna viridis were conducted by short-term bioassays using endpoints growth production and mortality, respectively. The 5-day EC(50) and 24-h LC(50) of these heavy metals were determined in the brown alga and mussel, respectively. The EC(50) values calculated for the alga were 0.74 mg/l for Cd, 0.91 mg/l for Cu, 1.40 mg/l for Pb and 0.60 mg/l for Zn. The LC(50) values for the mussels were 1.53 mg/l for Cd, 0.25 mg/l for Cu, 4.12 mg/l for Pb and 3.20 mg/l for Zn. These LC(50) values were within the concentration ranges as reported by other authors who used P. viridis as the test organism. Based on these EC(50) and LC(50) values, the alga was most sensitive to Zn, followed by Cd, Cu and Pb while the mussel was most sensitive to Cu, followed by Cd, Zn and Pb. Differences in the trophic levels, metal handling strategies, biology and ecology of the primary producer (brown alga) and the primary consumer (mussel) are believed to be the plausible causes for the different toxicities and tolerances of the metals studied.