Effects of climate change on coastal disasters: new methodologies and recent results

Humanity faces an increasing possibility that unusual and extreme natural disasters will increase, compounded with climate change, including global warming. These compound events are designated as compounded natural hazards in this study. A methodology must be developed for predicting what events and risks will confront future societies, to propose countermeasures and adaptation strategies against these events, and to evaluate the influences of compound disasters on infrastructure which is particularly situated near coasts and rivers. Based on the above-stated background and demands, this study was undertaken with the intention of upgrading the methodology for estimating effects on infrastructure of compound events such as increased typhoon and rainfall severity caused by global warming occurring concurrently with a great earthquake in Japan. Such a methodology is expected to contribute to progress in the fields of natural disaster mitigation and land preservation, particularly benefiting coastal and river areas in Japan. Additionally in this study, risk and economic loss analyses for the possible occurrence of compound disasters for coastal infrastructure and foundations are produced for establishing environmental strategies at the governmental level. The authors further propose adaptation strategies and techniques as countermeasures against these events.     

Healthcare waste management in the capital city of Mongolia

Inconsistencies are present in the management options for healthcare wastes in Mongolia. One of the first critical steps in the process of developing a reliable waste management plan requires the performance of a waste characterization analysis. The objectives of this study were an assessment of the current situation of healthcare waste management (HCWM) and characterization of healthcare wastes generated in Ulaanbaatar. A total about 2.65 tonnes of healthcare wastes are produced each day in Ulaanbaatar (0.78 tons of medical wastes and 1.87 tons of general wastes). The medical waste generation rate per kg/patient-day in the inpatient services of public healthcare facilities was 1.4-3.0 times higher than in the outpatient services (P<0.01). The waste generation rate in the healthcare facilities of Ulaanbaatar was lower than in some other countries; however, the percentage of medical wastes in the total waste stream was comparatively high, ranging from 12.5% to 69.3%, which indicated poor waste handling practices. Despite the efforts for the management of wastes, the current system of healthcare waste management in Ulaanbaatar city of Mongolia is under development and is in dire need of immediate attention and improvement. It is essential to develop a national policy and implement a comprehensive action plan for HCWM providing environmentally sound technological measures to improve HCWM in Mongolia.     

Levels and regional trends of persistent organochlorines and polybrominated diphenyl ethers in Asian breast milk demonstrate POPs signatures unique to individual countries

Human breast milk samples collected in 2007–2008 from four countries, Vietnam (Hanoi), China (Beijing), Korea (Seoul) and Japan (Sendai, Kyoto and Takayama), were analyzed for persistent organic pollutants (POPs) such as dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane-related compounds (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Comparing with previous surveys, the present study indicates that the DDTs in breast milk from China and Vietnam had gradually decreased during the last decade, but were still 5–10 times higher than those in other nations. The ratios of p,p′-DDE/p,p′-DDT and o,p′-DDT/p,p′-DDT were higher in Beijing than in the other countries, suggesting that there is less fresh intake of commercial DDT products and a possible exposure to dicofol in China. CHL and PCB levels were relatively higher in mothers from Japan, whereas β-HCH and HCB were more common in Chinese women. In Japan, it is suspected that mothers in the urban/coastal area (Sendai) were more continuously exposed to organochlorine pesticides (OCPs) than mothers in the rural/inland area (Takayama). In addition, OCP levels in primiparae were significantly higher than those in multiparae from Japan and Korea. These indicate that both parity and regional factors are major determinants of the levels of OCPs and PCBs in human milk. On the other hand, higher concentrations of PBDEs were observed in mothers' milk from Korea. The congener was dominated by BDE-47 (43–54%), followed by BDE-153 (23–33%) in all regions except for Beijing where BDE-28 (23%) was relatively abundant. In Japanese breast milk, regional and parity-dependent distributions were not observed for PBDEs. Among PBDE congeners, age-dependency was observed for BDE-153, which was negatively correlated (p < 0.05) to the age of mothers in Kyoto (17 participants were housewives), while it increased with age in Sendai (10 participants were clerks). No such correlation was seen for BDE-47, indicating that BDE-47 was ingested and assimilated via different kinetics or routes from BDE-153 in Japan.     

Neurologic features of chronic minamata disease (organic mercury poisoning) and incidence of complications with aging

Abstract

To elucidate the neurologic features of chronic Minamata disease, and the incidence of complications with aging, we studied 80 patients with documented Minamata disease (organic mercury poisoning) from 1986 to 1994 (mean age: 63 years). Of the cardinal neurologic findings, sensory impairment was seen with highest frequency in 98.8% of patients limited to the extremities in 86.3%. Impairment of lower extremity coordination was observed in 60%, constriction of the visual field in 51.9%, and retrocochlear hearing loss in 41%. To assess age‐related complications, patients were separated into three groups by age: Group I (10 to 39 years); Group II (40 to 69 years); Group III (≥7 0 years). The incidences of hypertension and cerebrovascular diseases, organic ophthalmologic disorders (including cataracts), presbyacusis, and cervical spondylosis deformans increased significantly with age. Compared with a preceding survey (1981 to 1985, 171 patients, mean age: 63.5 years), the incidences of complicated hypertension and cataracts had decreased, whereas those of cerebrovascular disease and retinitis pigmentosa remained unchanged. The incidences of abnormal brain computed tomography (CT), presbyacusis, cervical spondylosis deformans, and positive tests for urine sugar also increased. The incidences of these complications other than retinitis pigmentosa were similar to those in the general population. These results accurately reflect the recent epidemiological disease tendencies in Japan toward a decreased incidence of hypertension and an increased incidence of diabetes.     

Formation of chlorodibenzofurans by thermal decomposition of vinylidene chloride polymer

This is the first reported measurement of four kinds of chlorodibenzofurans formed in the pyrolytic decomposition of vinylidene chloride, a polymer used as wrapping film. 3-Chloro isomer was the most abundant among four monochlorodibenzofurans.     

Dechlorination of PCBs by electrochemical reduction with aromatic radical anion as mediator

Mediated electrochemical reduction was applied to the dechlorination of polychlorinated biphenyls (PCBs) in tetra-n-butylammonium perchlorate/dimethylformamide solution. Rapid and complete dechlorination was possible with biphenyl or naphthalene as the mediator, whereas the reaction was much slower with anthracene or 9,10-diphenylanthracene. The reaction rate was so high with naphthalene or biphenyl radical anion that differences in reactivity could not be observed between congeners. Side reactions, other than biphenyl formation, could occur depending upon the mediators and the substrates, but contributed less than 10% of the total products in the case of naphthalene-mediated dechlorination. Almost all chloride ion formed in the dechlorination remained in the cathode solution. The order of the reaction was determined to be 0.5 for the substrate and 1 for the mediator (naphthalene) in the dechlorination of 2-chlorobiphenyl; identical to results for the mediated dechlorination of 1-chloronaphthalene. The reaction rate in practical PCB dechlorination could be estimated with the use of the initial concentration of the mediator and chlorine content of the solution provided that the problem of the deactivation of the electrode surface could be solved.     

Investigation of the self-heating and spontaneous ignition of refuse-derived fuel (RDF) during storage

Refuse-derived fuel (RDF)—RDF-5 according to ASTM guidelines—derived from municipal solid waste and other waste materials, has been prepared as a fuel source for power plants in Japan. RDF has been known as a stable and safe solid-fuel. However, some spontaneous ignition incidents occurred during storage of RDF in certain facilities. In the present study, the storage conditions, which might induce the spontaneous ignition in RDF samples, was investigated to understand and prevent this phenomenon. When the initial temperature of RDF sample was consistent, higher water content and shorter induction times was observed (e.g., the induction times of select RDF samples with 5.8% and 16.7% water content, was 446 and 270 min, respectively). Also, the induction time was affected by the size of a RDF sample. No relationship between bacterial fermentation and spontaneous ignition was observed. The linear relationship between the induction time and the inverse of the initial temperature of the RDF sample was obtained in the Arrhenius equation.     

Improved preparation of recycled polymers in chemical recycling of fiber-reinforced plastics and molding of test product using recycled polymers

We examined an improved preparation method of recycled unsaturated polyester resin from recovered monomeric materials obtained from the depolymerization of fiber-reinforced plastics (FRPs). The formation of unsaturated polyester progressed smoothly in the presence of catalytic amounts of Ca(OAc)₂ and Ti(OBu)₄. The quality of the resin was estimated by the durometer hardness test. The strength test of FRP board prepared from recycled resin showed sufficient hardness for practical use (about 94% of the tensile strength of new resin). We examined the recycled resin by using it to mold successfully an actual test product.