Isomer-specific analysis of chlorinated biphenyls,naphthalenes and dibenzofurans in Delor: polychlorinated biphenyl preparations from the former Czechoslovakia

Technical polychlorinated byphenyl (PCB) preparations--Delors 103, 104, 105, and 106--produced in the former Czechoslovakia were analyzed for their chlorobiphenyl (CB), chloronaphthalene (PCN) and chlorinated dibenzofuran (PCDF) composition and content using high resolution gas chromatography-mass spectrometry techniques. The congener patterns of Delors 103, 104, 105, and 106 resembled Aroclors 1242, 1248, 1254, and 1260. Delors contained PCNs and PCDFs, as impurities, at microgram per gram concentrations. Concentrations of PCNs and PCDFs in Delors were greater than those found in the corresponding Aroclors. The potential for the emissions of PCNs and PCDFs from Delor was estimated to be 3680 and 860 kg, respectively. Non- and mono-ortho PCBs were the major contributors to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents in Delor mixtures.     

Study on 14C-BHA absorption and distribution in rat

BHA was administered to rats at doses of 5 or 500 mg/kg for seven days. ¹⁴C-BHA absorption was investigated on the eighth day and compared with animals receiving a single dose of 5 or 500 mg/kg BHA. Absorption of ¹⁴C-BHA was proportionately greater at the high dose rats. ¹⁴C distribution was 3–6 times higher in the forestomach than in the pyloric region of the stomach. The urinary excretion of BHA conjugates was not dependent on pretreatment with BHA or on the dose.     

Estimation of sources and inflow of dioxins and polycyclic aromatic hydrocarbons from the sediment core of Lake Suwa, Japan

To elucidate the historical changes in polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), coplanar polychlorinated biphenyl (co-PCB), and polycyclic aromatic hydrocarbon (PAH) inflows in Lake Suwa, their concentrations in the sediment core were analyzed in 5 cm interval. The maximum concentrations (depth cm) of PCDDs/DFs, co-PCBs, and PAHs were 25.2 ng/g dry (30-35 cm), 19.0 ng/g dry (30-35 cm), and 738, 795 ng/g dry (50-55 cm, 30-35 cm), respectively. Age and sedimentation rate of the sediment were estimated from the vertical changes in apparent density. Deposition rate of dioxins and PAHs were calculated from the concentration and sedimentation rate of the sediment. The results indicate that large amounts of dioxins and PAHs flowed into the lake in flood stage compared to normal stage.     

Sub-lethal exposure to ultraviolet radiation reduces prey consumption by Atlantic cod larvae (Gadus morhua)

Levels of ultraviolet-B radiation (UV-B: 280–315 nm) reaching the earth’s surface have increased over the past few decades due to ozone depletion. It is well documented that exposure to UV-B radiation increases mortality in marine fish larvae. However, few studies have examined sub-lethal effects of UV-B radiation such as, for example, the possibility that it affects prey consumption by fish larvae. Atlantic cod larvae were exposed to a sub-lethal level of ultraviolet-B radiation (UV-B: 280–315 nm) for 15 h. After the exposure, rotifers (4/mL) were fed to cod larvae at three different post-exposure intervals (20 min, 3 and 6 h). Trials were replicated three times for each post-exposure interval. The number of rotifers in the gut and the percent of empty guts (number of fish with empty gut/number of fish examined × 100) were analyzed. Results were compared to those of unexposed fish (the control treatment). UV-B exposed cod larvae had consumed significantly fewer rotifers than control fish at all post-exposure intervals. There was no significant difference in the frequency of empty guts between fish in the UV-B treatment versus fish in the control treatment at any of the post-exposure time points (although the difference at 20 min post-exposure was borderline significant). These observations suggest that cod larvae exposed to sub-lethal levels of UV-B have lower net energy gain which may lead to reduced growth rate and possibly poorer survival.     

Muscle tetanus and loading condition effects on the elastic and viscous characteristics of the thorax

Thoracic deformation under an applied load is an established indicator of injury risk, but the force required to achieve an injurious level of deformation currently is not understood adequately. This article evaluates how two potentially important factors, loading condition and muscle tensing, affect the structural response of the dynamically loaded thorax. Structural models of two human cadaver thoraxes and two porcine thoraxes were used to quantify the effects. The human cadavers, which represent anthropometric extremes, were subjected to anterior loading from (1) a 5.1-cm-wide belt oriented diagonally (i.e., seatbelt-like loading), (2) a 15.2-cm-diameter rigid hub, and (3) a 20.3-cm-wide belt oriented laterally (i.e., a distributed load). A structural model having the mathematical formulation of a quasilinear viscoelastic material model was used to model the elastic and viscous response, with ramp-hold tests used to determine the model coefficients. The effect of thoracic musculature was assessed using similar ramp-hold tests on the porcine subjects, each with and without forced muscle contraction. Even maximally contracted thoracic musculature is shown to have a minimal effect on the response, with similar elastic and viscous characteristics exhibited by each subject regardless of muscle tone. The elastic response is shown to be approximately a factor of three stiffer for diagonal belt loading and for this distributed loading condition than for the hub loading, indicating that the response is influenced most by the particular anatomical structures that are engaged and, secondarily, by the area of load application. Specifically, shoulder involvement is shown to have a strong influence. The force relaxation is found to be pronounced, but insensitive to the loading condition, with long-time force relaxation coefficients (G( infinity )) in the range of 0.1 to 0.3. The findings of this study provide restraint-specific guidelines for the force-deflection characteristics of both physical and computational thoracic models.     

Separation and recovery of carbon dioxide by a membrane flash process

A novel process for carbon dioxide (CO₂) separation, which was named a membrane flash process, was developed to realize an energy-saving technology and to substitute it for a conventional regenerator. The electric energy for CO₂ recovery in a membrane flash process using aluminum oxide and diethanolamine was lower than the thermal energy of the conventional chemical absorption process. Flashing at elevated temperature by the low temperature energy significantly reduced the electric energy and required much less membrane area. This process has potentiality of low cost capture of CO₂ when the low temperature energy, which is not available for other purposes, can be utilized to elevate flashing temperature.     

Occurrence and fate of polycyclic musks in wastewater treatment plants in Kentucky and Georgia, USA

Wastewater treatment plants (WWTPs) are a potential of source of polycyclic musks in the aquatic environment. In this study, contamination profiles and mass flow of polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[gamma]-2-benzopyran (HHCB), 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), and HHCB-lactone (oxidation product of HHCB), in two WWTPs, one located in Kentucky (Plant A, rural area) and the other in Georgia (Plant B, urban), USA, were determined. HHCB, AHTN and HHCB-lactone were detected in the influent, effluent, and sludge samples analyzed. The concentrations in wastewater samples varied widely, from 10 to 7,030 ng/l, 13 to 5,400 ng/l, and 66 to 790 ng/l, for HHCB, AHTN, and HHCB-lactone, respectively. Sludge samples contained HHCB at <0.02-36 microg/g dry weight, AHTN at <0.02-7.2 microg/g dry weight, and HHCB-lactone at <0.05-17 microg/g dry weight. Based on the daily flow rates and mean concentrations of polycyclic musks, the estimated discharge of total polycyclic musks to the rivers was 21 g/day from Plant A and 31 g/day from Plant B. Mass balance analysis suggested that only 30% of HHCB and AHTN entering the plants was accounted for in the effluent and the sludge. Removal efficiencies of HHCB and AHTN in the two WWTPs ranged from 72% to 98%. In contrast, HHCB-lactone concentrations increased following the treatment. Concentrations of polycyclic musks in sludge were on the order of several parts per million. Incineration of sludge at one plant reduced the concentration of polycyclic musks.     

Material flows of end-of-life home appliances in Japan

In Japan, the Law for the Recycling of Specified Kinds of Home Appliances came into effect in April 2001. This law aims to introduce appropriate waste treatment and promote the efficient use of resources so that we can achieve a sound material-cycle society. The law introduces a new framework for recycling that places obligations principally on the manufacturers and retailers of home appliances. Material flow analysis of this new framework is essential for evaluation of the system and for finding any problems that may exist. We therefore analyzed the material flows in facilities that recycle electrical home appliances. The mass balances in the recycling facilities were appropriately estimated. Then the potential destinations were surveyed and analyzed, even though the legal framework does not include flows after the recycling facilities. The potential destination after the facilities varies and depends on both the economy and the related regulations. Currently, considerable amounts of recovered materials are exported and recycled. However, the sustainability of these trades is unknown. Therefore, we should keep a close eye on the situation and make sure that our recycling system is adaptable to meet any future changes.     

Evaluation of the effect of automotive bumper recycling by life-cycle inventory analysis

This paper describes a case study of the application of life-cycle inventory analysis to automotive bumper recycling. Two scenarios of bumper recycling are compared. One is “bumper-to-bumper recycling,” in which we recycle bumpers into more bumpers. The other is “cascade recycling,” in which bumpers are recycled into different parts of a car with a lower function. Inventory analysis is applied to both these recycling scenarios by analyzing the stages of acquiring natural resources, manufacturing materials, and parts, disposal, and recycling. We chose air emission, solid waste, and fossil fuel resources as items of the inventory analysis. We quantified the effect of reductions in the environmental load by recycling bumpers, and found that reductions in the environmental load were larger with cascade recycling than with bumper-to-bumper recycling based on current conditions. Received: February 2, 2000 / Accepted: April 21, 2000