Behavior of endocrine-disrupting chemicals in leachate from MSW landfill sites in Japan

Endocrine-disrupting chemicals (EDCs) in landfill leachates and the effluent from leachate treatment facilities have been analyzed by many researchers. However, seasonal and yearly variations and the influence of landfill age are still not clear. In this study, leachate was sampled on four occasions each, at different seasons, from two MSW landfills which receive different waste material. Then, the quantities of alkylphenols (APs), bisphenol A (BPA), phthalic acid esters (PAEs) and organotin compounds (OTs) in leachate were determined. By sampling leachate from landfill cells of different age, the long-term behavior of EDCs was studied. Furthermore, leachate was also sampled at different points in the process of a leachate treatment system, and then the behavior of EDCs in the facility was studied. The concentrations of APs were as low as in surface waters, and OTs were not detected (detection limit was 0.01 microg/l), while BPA and DEHP, which were the most abundant of the four substances measured as PAEs, were found in all the leachates that were measured. Concentrations of BPA and DEHP were almost constant regardless of season, except for a couple of low concentrations observed for BPA. The varying composition of landfilled waste did not influence BPA and DEHP in leachate. Concentration of BPA in raw leachate tends to decrease as the years go by, but the concentration of DEHP was observed to remain at a constant level. BPA was considerably degraded by aeration for leachates from the two landfills, except when the leachate temperature was low. Aeration, coagulation/sedimentation, and biological treatment could not remove DEHP.     

Recent trends in recycling activities and waste management in Japan

Japan's basic approach to municipal solid waste (MSW) is (1) waste reduction, (2) promotion of recycling, (3) volume reduction by intermediate treatment, and (4) environmentally sound final disposal. A brief history of legislative trends in waste management is given as background for current waste management and recycling activities. The material recovery rate for MSW collected by local municipalities was only 5.6% in 1996. More than half of MSW, on a volume basis, consists of containers and packages, while great amounts of landfill space are also taken up by bulky wastes such as electric appliances. Therefore, in order to promote recycling and decrease landfill waste, Japan is targeting containers, packages, and electric appliances. A law promoting separate collection and recycling of containers and packages (Packaging Waste Recycling Law) and a law requiring the recycling of specific home electric appliances into new products (Home Electric Appliance Recycling Law) were introduced in June 1995 and June 1998, respectively. These laws are in line with the OECD policy Extended Producer Responsibility (EPR). Received: September 16, 1998 / Accepted: March 10, 1999     

Resolving public conflict in site selection process-a risk communication approach

In Japan, conflicts regarding the siting of waste disposal facilities occur frequently. In particular, siting of incinerators and landfills has become increasingly difficult because the public is highly concerned about the dioxin issues. Inefficient siting of waste disposal facilities causes several social problems, such as the shortage of waste treatment and disposal facilities, the rising of waste management costs and an increase in the consumption of resources. While dealing with a similar situation, the Chemical Society of Japan adopted a risk communication technique successfully. Hence, the pragmatic use of a risk communication technique is proposed to avoid conflicts and for a smooth information exchange to seek cooperation in waste management. In order to achieve this, a study was conducted to resolve conflicts between residents and the municipality for the selection of site for a solid waste treatment and disposal facility. This study aims to discuss the subject of risk communication for the waste disposal system in Japan. This study is performed through personal interviews and a questionnaire covering opposing parties in the town. As a result of the survey, a risk communication approach for a waste treatment and disposal system is presented in the paper addressing issues such as building of social trust, pragmatic use of the communication process, installation of credible information sources, and environmental education and awareness.     

Toxicity to medaka of solutions of fenitrothion degraded by strong alkali

Various experiments were conducted to examine the effects of degradation products on organisms. Fenitrothion (MEP) emulsions adjusted to pH 10 or 14 were degraded by exposure to natural sunlight in winter with heat. Medaka eggs were exposed to various concentrations of the degraded solutions and an untreated MEP emulsion for 5 days starting 4-5 h following fertilisation. The eggs were then allowed to develop in dechlorinated tap water until the fish reached 3 months of age. The hatching rate and rate of survival in the degraded solutions tended to be lower than those in the untreated MEP emulsion, and the incidence of abnormal fry in the degraded solutions was higher than that of the untreated MEP emulsion. It thus appears that degradation products formed by MEP have toxic effects on medaka.     

Photocatalytic oxidation of NOx using composite sheets containing TiO2 and a metal compound

The photocatalytic oxidation of nitrogen oxides (NO(x)) over titanium dioxide (TiO(2)) sheets containing metal compounds (MCs) had been studied. Calcium oxide (CaO), magnesium oxide (MgO), calcium carbonate (CaCO(3)), aluminium oxide (Al(2)O(3)) and ferric oxide (Fe(2)O(3)) were used as MCs. Al(2)O(3) and Fe(2)O(3) added to the TiO(2) sheet did not affect the photooxidation of nitrogen oxides (NO(x)). The CaO sheet treated with TiO(2) sol had the greatest efficiency as a NO(x) remover under UV irradiation. It is believed that CaO has a high adsorptivity for nitrogen dioxide (NO(2)) and nitric acid (HNO(3)). The amount of NO(x) removed by a TiO(2) sheet including MC showed a tendency to increase with increasing pH of the MC suspension, i.e. there is a good correlation between the alkalinity of the MC and the retention of NO(2) and HNO(3).     

Fe and UV-enhanced ozonation of chlorophenolic compounds in aqueous medium

Mono-, di- and trichlorophenol including different isomers were degraded by O₃, O₃ + UV and O₃ + UV + Fe³⁺. Disappearance rates are nearly identical among three ozonations. Whereas TOC elimination was not completed by ozone alone. UV illumination accelerated TOC elimination rate and the addition of Fe³⁺ (O₃ + UV + Fe³⁺) further accelerated it. TOC elimination rates among different chlorophenols were in the order of mono > di > tri. The effect of Fe³⁺ was largest on the degradation of trichlorophenol. Hydroxylated aromatics, organic acids, formaldehyde and acetone were detected as intermediates.     

Global pollution monitoring of butyltin compounds using skipjack tuna as a bioindicator

Butyltin compounds (BTs) including mono- (MBT), di- (DBT), tri-butyltin (TBT) and total tin (sigmaSn), were determined in the liver of skipjack tuna (Katsuwonus pelamis) collected from Asian offshore waters (off-Japan, the Japan Sea, off-Taiwan, the East China Sea, the South China Sea, off-Philippines, off-Indonesia, the Bay of Bengal), off-Seychelles, off-Brazil and open seas (the North Pacific). BTs were detected in all the skipjack tuna collected, suggesting widespread contamination of BTs even in offshore waters and open seas on a global scale. Considering specific accumulation, Sex-, body length- differences and migration of skipjack tuna did not seem to affect BT concentrations, indicating rapid reflection of the pollution levels in seawater where and when they were collected. Skipjack tuna is a suitable bioindicator for monitoring the global distribution of BTs in offshore waters and open seas. High concentrations of BTs were observed in skipjack tuna from offshore waters around Japan, a highly developed and industrialized region (up to 400 ng/g wet weight). Moreover skipjack tuna collected from offshore waters around Asian developing countries also revealed the levels comparable to those in Japan (up to 270 ng/g wet weight) which may be due to the recent improvement in economic status in Asian developing countries. High percentages (almost 90%) of BTs in total tin (sigmaSn: sum of inorganic tin+organic tin) were found in the liver of skipjack tuna from offshore waters around Asian developing countries. This finding suggests that the anthropogenic BTs represent the major source of Sn accumulation in skipjack tuna from these regions.     

Supercooling ability in the house spider, Achaearanea tepidariorum: effect of field-collected and laboratory-reared prey

The influence of prey animals on the supercooling ability of the house spider, Achaearanea tepidariorum, was studied by feeding spiders with field-collected and laboratory-cultured prey animals. Irrespective of the prey species supplied, spiders given field-collected prey had a higher supercooling point than those given laboratory-cultured counterparts. This means that (1) the field prey animals contained some efficient ice nucleators, whereas the laboratory animals were free from such substances and (2) the ice nucleators must be of external origin. Several lines of evidence also suggest that, under natural conditions, potential prey animals for the house spider are highly contaminated with ice nucleators.     

Mathematical equivalence of geometric mean fitness with probabilistic optimization under environmental uncertainty

Natural selection can be considered as optimising fitness. Because ‘mean’ fitness is maximized with respect to the genotypes of carriers, traditional theory can be viewed as a statistical theory of natural selection. Probabilistic optimisation is a way to incorporate such uncertainty into optimality analyses of natural selection, where environmental uncertainty is expressed as a probability distribution. Its canonical form is a weighted average of fitness with respect to a given probabilistic distribution. This concept should be applicable to three different levels of uncertainty: (1) behavioural variations of an individual, (2) individual variations within a generation, and (3) temporal change over generations (geometric mean fitness). The former two levels are straightforward with many empirical evidences, but the last category, the geometric mean fitness, has not well understood. Here we studied the geometric mean fitness by taking its logarithm, where the log growth rates become the fitness value. By further transforming the log growth rates, the fitness of log growth rates becomes its linear function. Therefore, a simple average of these distributions becomes the fitness measure across generations and consideration of variance discount or the entire probability distributions becomes unnecessary. We discuss some characteristic features of probabilistic optimization in general. Our view is considered a probabilistic view of natural selection, in contrast with the traditional statistical view of natural selection.