Combinatorial bio/chemical analysis of dioxin and dioxin-like compounds in waste recycling, feed/food, humans/wildlife and the environment.

The present review describes international activities using bioassays/biomarkers in combination with chemical analysis to measure the effects of dioxin and dioxin-like compounds (DLCs) in the environment. The above authors reviewed already the state-of-art bioanalytical detection methods (BDMs) for dioxins and DLCs [Environ Int (2001)]. The aim of this study will be to review applications of these bioassays/biomarkers to evaluate potential dioxins and DLCs. The present literature study lists relative potencies (REPs) of polyhalogenated dibenzo-p-dioxins and -furans (PXDD/Fs; X = Cl, Br, F), their thio analogues polychlorinated dibenzothiophenes (PCDTs) and thianthrens (PCTAs), polyhalogenated biphenyls (PXBs), polychlorinated naphthalenes (PCNs) and other Ah receptor agonists measured by several biodetectors (Tier 3 screening). The authors will discuss some examples of the applications of some of these biodetectors in biomonitoring programmes and recently occurred dioxin crisis in feed/food. The diagnosis of the biopotency of these pollutants in technical processes like thermally treated waste, waste water treatment, landfill leachate treatment, commercial PCB-mixtures, the release into the environment (soil, air and water) and the final intake into wildlife and humans will be reviewed.     

Greenhouse gas reduction potential by household waste prevention

Journal of Material Cycles and Waste Management - We used a life-cycle assessment (LCA) approach to estimate the greenhouse gas (GHG) reduction effects of preventing 50% of all avoidable household...     

Flame retardants in indoor dust and air of a hotel in Japan

Occurrence of flame retardants (FRs) in the indoor environment of highly flame-retarded public facilities is an important concern from the viewpoint of exposure because it is likely that FRs are used to a greater degree in these facilities than in homes. For this study, brominated flame-retardants (BFRs) and organophosphate flame-retardants and plasticizers (OPs), and brominated dibenzo-p-dioxins/furans (PBDD/DFs) were measured in eight floor dust samples taken from a Japanese commercial hotel that was assumed to have many flame-retardant materials. Concentrations of polybrominated diphenylethers (PBDEs) and hexabromocyclododecanes (HBCDs) varied by about two orders of magnitude, from 9.8–1700 ng/g (median of 1200 ng/g) and from 72–1300 ng/g (median of 740 ng/g), respectively. Concentrations of the two types of BFRs described above were most dominant among the investigated BFRs in the dust samples. It is inferred that BFR and PBDD/DF concentrations are on the same level as those in house and office dust samples reported based on past studies. Regarding concentrations of 11 OPs, 7 OPs were detected on the order of micrograms per gram, which are equivalent to or exceed the BFR concentrations such as PBDEs and HBCDs. Concentrations of the investigated compounds were not uniform among dust samples collected throughout the hotel: concentrations differed among floors, suggesting that localization of source products is associated with FR concentrations in dust. Passive air sampling was also conducted to monitor BFRs in the indoor air of hotel rooms: the performance of an air cleaner placed in the room was evaluated in terms of reducing airborne BFR concentrations. Monitoring results suggest that operation of an appropriate air cleaner can reduce both gaseous and particulate BFRs in indoor air.     

Analyzing the hydrologic effects of region-wide land and water development interventions: a case study of the Upper Blue Nile basin

In the drylands of the Upper Blue Nile basin, high climate variability and land degradation are rampant. To enhance adaptive capacity in the region, various soil and water conservation interventions have been implemented. Moreover, water resources development schemes such as the Grand Ethiopian Renaissance Dam should be implemented by 2025. We modeled the effects of these interventions on surface runoff in the basin for both current and future (2025) basin conditions, using the runoff coefficient method in a spatially explicit approach. Under current conditions, we observed high spatial variability of mean annual runoff. The northeastern Blue Nile-1 sub-basin produces the highest mean annual runoff (391 mm or 10 × 10⁹ m³), whereas the northwestern Blue Nile-2 sub-basin produces the lowest mean annual runoff (178 mm or 0.2 × 10⁹ m³). The basin generates a total annual runoff volume of 47.7 × 10⁹ m³, of which about 54 % comes from cultivated land. The strong association between land use and topography masked the direct effect of rainfall on runoff. By 2025, total annual runoff yield could decrease by up to 38 % if appropriate basin-wide soil and water conservation interventions and the Grand Ethiopian Renaissance Dam are implemented. However, the full effects of most physical structures will only last for 1 or 2 years without regular maintenance. The improved understanding of the dynamics of the Upper Blue Nile basin’s hydrology provided by the present study will help planners to design appropriate management scenarios. Developing the basin’s database remains important for a holistic understanding of the impacts of future development interventions.     

Synthesis of novel polymer type sulfoxide solid phase combined with the porogen imprinting for enabling selective separation of polychlorinated biphenyls

We developed a novel polymer type sulfoxide-modified solid phase enabling to achieve selective separation of polychlorinated biphenyls (PCBs) from insulation oil. In this study, firstly we prepared base-polymer based on the concept of the molecular imprinting to capture PCBs in selectively, then, the sulfoxide groups were modified on the pore surface of base-polymers by changing preparation methods. As results of liquid chromatographic analyses for the polymers as columns, the base-polymer prepared by xylene as a porogenic solvent showed selective retention ability for chlorinated aromatic compounds by the porogen imprinting effect. Additionally, the polymer-type sulfoxide solid phases showed highly retention ability for PCBs by increasing amount of introduced sulfoxide groups. Consequently, the results of separation of PCBs comparing to insulation oil suggested that the prepared solid phase can be used for the selective separation of PCBs at the same level as a commercially available media utilized for the regulated method.     

An international comparative study of end-of-life vehicle (ELV) recycling systems

End-of-life vehicles (ELV) have become a global concern as automobiles have become popular worldwide. An international workshop was held to gather data and to discuss 3R policies and ELV recycling systems, their background and present situation, outcomes of related policies and programs, the framework of recycling and waste management, and case studies on related topics in several countries and regions, as well as the essential points of the comparison. Legislative ELV recycling systems are established in the EU, Japan, Korea, and China, while in the US, ELV recycling is managed under existing laws on environmental protection. Since automobile shredding residue (ASR) has a high calorific value and ash content, and includes heavy metals as well as a mass of unclassified fine particles, recycling ASR is considered highly difficult. Countries with a legislative ELV system commonly set a target for recovery rates, with many aiming for more than 95 % recovery. In order to reach this target, higher efficiency in ASR recovery is needed, in addition to material recycling of collectable components and metals. Environmentally friendly design was considered necessary at the planning and manufacturing stages, and the development of recycling systems and techniques in line with these changes are required for sound ELV management.     

Congener profiles of PCB and a proposed new set of indicator congeners

In this study, a new method for calculating total PCB and toxic equivalents (TEQ) of coplanar PCB (Co-PCB) was proposed, called the 'PCB dual method'. This method analysed various kinds of technical PCB, samples contaminated by technical PCB and byproduct PCB. In the PCB dual method, a data set of 15 indicator congeners was utilized for the calculations, having IUPAC nos. #3, #8, #28, #52, #77, #101, #105, #118, #126, #138, #153, #180, #194, #206 and #209. The 15 congener set was chosen from the major congeners, determined by HRGC/HRMS analysis, in 18 technical PCB, Kanechlor, Aroclor, Clophen and Chlorofen, and 20 other samples, such as indoor air, flue gases, emission gases, municipal solid waste (MSW), ash and sealant. To obtain total PCB and TEQ of Co-PCB, the intermediate sum for the concentration of the 15 congeners was multiplied by each multiplication factor. As a result, we obtained the average factor used to calculate total PCB in technical PCB and other samples. For technical PCB, the factor was 3.01, while for indoor air samples, flue and emission gases, MSW, ash and sealants, the factors were 3.92, 4.16, 3.68, 4.52 and 4.77, respectively. Moreover, the factor used to calculate the TEQ of Co-PCB in Kanechlor and other source samples were also obtained. The factors for Kanechlor, indoor air samples and emission gases from a cement plant were in the order of 10(-5), while the factor for flue gases in a MSW incinerator was in the order of 10(-3). These data were valuable for the rough estimation of the TEQ of Co-PCB without separation from other PCB before individual measurements.     

Degradation pathways of decabromodiphenyl ether during hydrothermal treatment

The hydrothermal degradation pathways of decabromodiphenyl ether during hydrothermal treatment were investigated. After an initial "Heating time", the reaction runs were carried out at constant temperature (heating to 300 degrees C and keeping temperature) and pressure (8MPa) in a SUS316 stainless steel micro autoclave filled with water. Some decomposition of decabromodiphenyl ether was observed over 200 degrees C, and it was decomposed by more than 99% after 10 min at 300 degrees C. The reactivities of bromine on para and meta substituents were relatively high, while its reactivity on ortho bromine was extremely low. The formations of polybrominated dibenzo-p-dioxins and furans (PBDD/DFs) were observed in the early stages of the reactions at around 300 degrees C. The TCDD toxicity equivalency (TCDD-EQs) of the by-products was determined based on relative potencies (REPs EC(5TCDD)) with the Dioxin-Responsive-Chemical Activated Luciferase gene eXpression (DR-CALUX) bioassays technology. These results indicated that the risk of formation of PBDD/DFs in the hydrothermal degradation of deca-BDE was low, and it would be possible to reduce the TCDD-EQs value by adding some catalyst or alkali, or extending processing time.     

Pathways and products of the degradation of PCBs by the sodium dispersion method

Nine polychlorinated biphenyl (PCB) congeners (2-chlorobiphenyl, 3-chlorobiphenyl, 4-chlorobiphenyl, 2,3,4-trichlorobiphenyl, 2,2',5,5'-tetrachlorobiphenyl, 2,3',4,4',5-pentachlorobiphenyl, 3,3',4,4',5-pentachlorobiphenyl, 2,2',4,4',5,5'-hexachlorobiphenyl, and decachlorobiphenyl) were dechlorinated by the sodium dispersion method (SD) at low temperature (60 degrees C). The dechlorination of 4-chlorobiphenyl was the fastest among the three monochlorobiphenyls. As for the other six congeners, we investigated the major dechlorination pathways. Although reaction selectivity was not very sensitive to the position of the chlorine substituent, the chlorines at the para position were slightly easier to dechlorinate than those at the ortho or meta positions. The decomposition rate increased with the total numbers of chlorine substituents. A chlorine situated between two other chlorines showed a high reactivity. When the numbers of chlorines on each of the phenyl rings were different, the reactions occurred on the more substituted ring. In the degradation of 4-chlorobiphenyl at elevated temperature (160 degrees C), we investigated the structures of the polymerized products and whether all the organic chlorinated compounds degraded finally or not. As for the dimers, p-quarterphenyl (QP) and m,p-QP were detected but not o-QP, m-QP, o,p-QP, o,m-QP, or the mono- to tetra-chlorinated QPs. Compounds with a molecular weight of 534.4183 or 758.6713 were detected. They were considered to have C40H54 or C56H86 as their molecular formula. The compounds were most probably the polymerized products resulting from coupling of hexadecane or two hexadecanes and two phenylcyclohexadienes. It was thought the dechlorination and the polymerization were the main reactions. All of many detected compounds were hydrocarbons without chlorines, and no peaks originating from organic chlorinated compounds were observed by mass spectroscopic (MS) methods.     

Transfer of brominated flame retardants from components into dust inside television cabinets

Television (TV) set components are highly flame resistant, with their added brominated compounds such as polybrominated diphenyl ethers (PBDEs). These compounds might be released indoors via dust, which presents a potential exposure pathway for humans in the home environment. In this study, we collected dust from inside TV sets and TV set component samples (parts of housing front cabinets, rear cabinets and circuit boards) of five sets used in Japan. We measured BFRs (i.e., PBDEs, tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs)) and polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/DFs). Analytical results of the TV components showed that the concentrations of PBDEs, TBBPA and PBDFs (48,000mug/g, 19,000mug/g and 9600ng/g as mean values, respectively) were all highest in the rear cabinets. The SigmaPBDD concentrations (460ng/g as a mean value) detected were highest in the circuit board samples. The respective SigmaPBDE and SigmaPBDF concentrations in the dust samples were 67-500mug/g (mean 300mug/g) and 180-650ng/g (mean 410ng/g). Such concentrations were 2-3 orders of magnitude higher than those previously reported for house dust samples, which suggests that the brominated compounds are transferred from TV components into dust. Comparison of congener patterns of the brominated compounds in the dust identified the components as the source of these BFRs.