US Energy Conservation and Efficiency: Benefits and Costs

With increased energy conservation plus the adoption of diverse energy efficient technologies, the US economy could save about 32 quads or about 33% of its current energy consumption, if sound conservation energy use policies were implemented over approximately 10 years. This potential of 32 quads is slightly greater than the current US oil imports. The systems that have the greatest potential to provide major energy savings are transportation, residential energy use, and the food system. Not only saving energy has merit in itself, but it would save US citizens approximately $438 billion per year, helping support the US economy, a high standard of living, and energy security. In addition, this analysis suggests that reducing the $40 billion in taxpayer money spent on subsidies of the energy industries would further increase conservation.     

Food-particle size and selection by bivalve larvae in a temperate embayment

Epifluorescence microscopy was used to analyze the stomach contents of bivalve larvae collected in the Baie des Chaleurs (western Gulf of St. Lawrence, Canada) in order to document food-particle sizes, compare feeding among taxa, and compare the diet with the in situ phytoplankton community. Stomach contents were mainly composed of small autotrophic flagellates (<5 μm) and cyanobacteria (<2 μm), reflecting the microbial food web which characterizes these waters. More than half (55%) of all veligers examined contained algal cells of 5 to 15 μm, whereas only 3% had cells of 15 to 25 μm. Differences in the size ranges of ingested algal cells among similar-sized larvae of different species suggests that veligers actively selected food particles. Among the smallest veligers (185 to 260 μm), scallops (Placopecten magellicanus) and mussels (Mytilus edulis) ingested more <5 μm and 5 to 15 μm algae than clams (Mya arenaria). Among larger veligers (261 to 405 μm), clams contained significantly more <5 μm cells than mussels, whereas mussels contained significantly more 5 to 15 μm algae than clams. Algal cells of 15 to 25 μm were preferentially ingested by mussel veligers. Feeding also differed between different-sized veligers within taxa, i.e. the smallest clam veligers ingested fewer of 5 to 15 μm algae than the larger size classes. Mussel veligers ingested significantly more 15 to 25 μm and fewer <5 μm cells as their size increased. The dominance of ultraplankton in the nearshore waters of Baie des Chaleurs and in the stomach contents suggests that veliger larvae may be an important export path for carbon produced by small phytoplankton. Received: 17 July 1996 / Accepted: 20 September 1996     

Mercury induced time-dependent alterations in lipid profiles and lipid peroxidation in different body organs of cat-fish Heteropneustes fossilis

The effects of mercuric chloride (HgCl2) on lipid profiles and lipid peroxidation in different body organs of fresh water cat-fish Heteropneustes fossilis were studied. The daily exposure of HgCl2 0.2 mg/L for 10, 20 and 30 days depleted the total lipids in brain. But the content of phospholipids enhanced significantly at 30 days. Significant diminution in C/P ratio was discernible with 30 days of exposure following mercury toxicosis. Liver exhibited elevated levels of total lipids, phospholipids, cholesterol and C/P ratio. Interestingly kidney showed marked decrease in the concentration of total lipids, cholesterol and C/P ratio at higher exposure. However, the phospholipid values increased during the longer exposure. The content of total lipids and phospholipids was high in muscle but the level of cholesterol and C/P ratio were depleted. Significant increment in lipid peroxidation was discernible in brain, liver and muscle. In kidney the rate of lipid peroxidation was significantly reduced. The results suggest that exposure of HgCl2 enhances the peroxidation of endogenous lipids in brain, liver and muscle. Interestingly the lipid contents are affected differently in different body organs.     

Sorption mechanism of DDT from aqueous phase

Sorption is one among the many techniques available for the removal of organic materials from potable water and waste water. Use of locally available Wood Charcoal (WC) is essential in place of costly activated charcoal to make the process more economical and lucrative. The vital objective of this investigation was to assess the performance of WC for the removal of DDT from the aqueous phase. The influence of important factors like, particle size, pH, and time of contact, which affects the sorption process was studied in this investigation using batch experiments. The removal kinetics were carried out under the temperature 27 degrees +/- 1 degrees C (room temperature) and the sorption kinetics constants were evaluated. Sorption equilibria study has also been carried out to develop the Freudlich's sorption isotherm equation from which the ultimate sorption capacity of WC for sorption of DDT was calculated.     

Status and prospects of environmental protection in Hong Kong

Summary Environmental protection in Hong Kong traditionally has been neglected by the government and private sector, with citizens showing little interest. The overwhelming pre-occupation with economic growth and a plethora of pressing social needs are often cited as the main excuses for past apathy. Since the late 1970s, the government has taken positive steps to establish administrative structures and statutes to arrest environmental decline. Legislative processes, however, have often been delayed and the effectiveness of the laws trimmed by the strong industrial lobby. The erratic developments in the 1980s nevertheless allowed the enactment of four dedicated environmental laws and a complement of ancillary control measures. The current status of the environment in the fields of water, waste, air and noise has been assessed to highlight the pertinent maladies and shortcomings. The 1989 White Paper provided a clear package of official policies and programmes to correct past ills in a ten-year comprehensive plan. The ameliorative measures, both present and projected, are evaluated for their effectiveness and prospects. Some issues that deserve more attention and improvements are suggested.     

Comparison of trace metal contents of sediments and mussels collected within and outside Tolo Harbour,Hong Kong

Sediments collected from Tap Mun (within Tolo Harbour) and Yim Tin Tsai (outside Tolo Harbour) were extracted sequentially and the copper, cadmium, and chromium contents were determined. Total contents of copper, cadmium, chromium, and arsenic were also detected by acid digestion. The level of heavy metal extracted was higher in sequential extraction (which extracted all forms of metal ions) than total acid digestion. Among the four heavy metals studied, only copper showed a significantly higher (P<0.001) level in samples collected from Yim Tin Tsai (16.10 mg/kg) than that from Tap Mun (3.19 mg/kg). Such a difference in copper level is mainly attributed to the significantly higher (P<0.05) levels of copper in the organic, carbonate, and sulfide forms, whereas there was no significant difference (P>0.05) in the exchangeable and sorbed forms. Green-lipped mussel (Perna viridis) samples collected from the two sites were dissected into seven parts (gill, byssus, siphon, shell, digestive gland, soft tissue, and adductor muscle) and the concentrations of copper, cadmium, chromium, and arsenic were measured. The highest concentration of copper was obtained in the byssus. A higher concentration of copper was also noted in the mussels collected from Yim Tin Tsai than those collected from Tap Mun. No specific trend was revealed for the other metals tested. Chromium and arsenic concentrations were found to be independent of the body size of the mussels. Copper had a lower concentration in larger mussels and cadmium level was found to decrease with size. In addition, the mussels collected from Tap Mun were much larger than those collected from Yim Tin Tsai.     

RISK OF EXTREME EVENTS IN A MULTIOBJECTIVE FRAMEWORK1

ABSTRACT: This paper summarizes advances made in risk-based decisionmaking in water resources through use of the partitioned multiobjective risk method (PMRM). (Risk is a measure of the probability and severity of adverse effects.) In the PMRM, the risk of extreme events is differentiated from risk involving less extreme damage severity and is evaluated within a multiobjective framework. Study of the extreme-event risk function f₄(*) has addressed the following issues: methods for calculating f₄(*); the sensitivity of f₄(*) to various parameters, particularly to the partitioning point of the extreme-event range and the selection of probability density functions; insight provided by the statistics of extremes; and the impact of f₄(*) on risk management, for example, in the application of the PMRM to water resources problems. In particular, this paper shares with the reader recent research results on the PMRM, the relationship between the statistics of extremes and the conditional expected value, derived formulas for f₄(*), distribution-free estimates of f₄(*), documented case studies in dam safety, and future research directions.     

Roadside dusts and soils contamination in Cincinnati,Ohio, USA

Roadside dusts and soils were collected from various nonindustrial districts in Cincinnati, Ohio, USA, and analyzed for lead and copper contents. Results showed that the recent lead phase-down action has reduced the level of lead, but the concentrations of both metals are still higher than the background levels for normal soil. Elevated concentrations of copper in heavily traveled highways were noted, suggesting that much of the copper pollutants is probably of automotive origin. The concentration of lead was found to vary with housing age, and higher levels of contamination in the older neighborhoods were observed. This result is probably ascribable to the accumulation of residues from leaded gasoline and lead-based paint in the past and the use of coal fire for space heating in older houses.