Distribution and abundance of finless porpoise in the Inland Sea of Japan

Aerial sighting surveys were conducted in 2000 to evaluate the distribution and abundance of finless porpoise Neophocaena phocaenoides in the Inland Sea of Japan. We flew 60 north–south transects (2,218 km in total) at intervals of 6.43 km over the study area between 131°3′ and 134°59′ E. In total, 148 groups were detected by two observers. The average group size was 1.56 individuals. The effective strip half-width of each observer was estimated to be 107 m (coefficient of variation [CV] = 8.26%). Porpoise abundance was estimated at 7,572 individuals and the density was as low as 0.506 individuals/km² (CV = 17.3%). The sea is among the Japanese waters with the lowest density in spite of its favorable topographical conditions. In the western stratum of the study area, where the estimated density was 1.31 individuals/km², we observed a relatively regular distribution. In the central-eastern stratum, which had an estimated density of 0.208 individuals/km², we confirmed a clumped distribution that was restricted to inshore waters or near islands. No individuals were observed in waters between 132°51′ and 133°11′E, and between 133°43′ and 133°59′E, where sand dredging and other human activities have been active, suggesting that habitat fragmentation has occurred.     

Quantities of bisphenol a leached from plastic waste samples

To quantify the leaching of bisphenol A into water, various samples of plastic waste were cut into small pieces, soaked in water for two weeks at room temperature in the dark, and the concentration of bisphenol A in the water determined by gas chromatography/mass spectrometry (GC/MS). The amount of bisphenol A leached from the plastic wastes ranged from undetectable to 139 micrograms/g. The detection limit was 2 ng/g when 100 g of plastic waste was used. Polyvinyl chloride products yielded the highest concentrations because bisphenol A is used in its manufacture as a stabilizer.     

Depth profiles of volatile halogenated hydrocarbons in seawater in the Bay of Bengal

Measurements were made of bromocarbons (CHBr3 and CH2Br2), iodocarbons (CH2I2 and CH2ClI), and dimethylsulfide (DMS, CH3SCH3) in seawater collected from the Bay of Bengal under tropical stratified conditions. These compounds showed different depth profiles, characteristic of each group. CH2I2 and CH2ClI showed very similar depth profiles to chlorophyll-a, suggesting their production by phytoplankton followed by rapid decay in seawater. The CH2I2 maximum at a depth a little below the CH2ClI maximum was consistent with its more significant photolytic decay. The bromocarbons were less localized in their distributions than were the iodocarbons, suggesting their longer residence time in seawater after their release from phytoplankton. Both of these profiles were different from the pattern of DMS, which had its maxima above the chlorophyll-a maximum layer near the surface.     

中国几个地区土壤中239,240Pu、241Am和137Cs等放射性核素的测定

分别从北京、太原、石家庄和济南地区采集了深度为0-5和5-20cm的土壤样品,进行了~(239,240)Pu、~(241)Am、~(137)Cs、~(40)K以及天然铀、钍系放射性核素的测定.估计了样品中放射性核素的水平和分布.结果表明,~(239,240)Pu、~(241)Am和~(137)Cs 的平均累积沉降量分别为24+13、10±5和1230±700MBq/km~2.~(239,240)Pu/~(137)Cs活度比为0.016—0.026(平均值0.020±0.004),~(214)Am/~(239,240)Pu活度比为0.35—0.49(平均值0.43±0.05).还讨论了这些核素与土壤中“过剩”~(210)Pb之间的关系.     

Thermal destruction of wastes containing polychlorinated naphthalenes in an industrial waste incinerator

A series of verification tests were carried out in order to confirm that polychlorinated naphthalenes (PCNs) contained in synthetic rubber products (Neoprene FB products) and aerosol adhesives, which were accidentally imported into Japan, could be thermally destroyed using an industrial waste incinerator. In the verification tests, Neoprene FB products containing PCNs at a concentration of 2800 mg/kg were added to industrial wastes at a ratio of 600 mg Neoprene FB product/kg-waste, and then incinerated at an average temperature of 985 °C. Total PCN concentrations were 14 ng/m³N in stack gas, 5.7 ng/g in bottom ash, 0.98 ng/g in boiler dust, and 1.2 ng/g in fly ash. Destruction efficiency (DE) and destruction removal efficiency (DRE) of congener No. 38/40, which is considered an input marker congener, were 99.9974 and 99.9995 %, respectively. The following dioxin concentrations were found: 0.11 ng-TEQ/m³N for the stack gas, 0.096 ng-TEQ/g for the bottom ash, 0.010 ng-TEQ/g for the boiler dust, and 0.072 ng-TEQ/g for the fly ash. Since the PCN levels in the PCN destruction test were even at slightly lower concentrations than in the baseline test without PCN addition, the detected PCNs are to a large degree unintentionally produced PCNs and does not mainly stem from input material. Also, the dioxin levels did not change. From these results, we confirmed that PCNs contained in Neoprene FB products and aerosol adhesives could be destroyed to a high degree by high-temperature incineration. Therefore, all recalled Neoprene FB products and aerosol adhesives containing PCNs were successfully treated under the same conditions as the verification tests.     

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.     

Reactivity between PbSO4 and CaCO3 particles relevant to the modification of mineral particles and chemical forms of Pb in particles sampled at two remote sites during an Asian dust event

During the transboundary transport of anthropogenic heavy metals by mineral particles providing reaction sites, the divalent metal salt PbSO₄ can be converted to PbCO₃ in the presence of water. We carried out laboratory experiments to study the transformation process under various conditions by incorporating test particles comprising CaCO₃ of a particulate mineral component, PbSO₄, and NaCl. After the immersion of PbSO₄ particles in contact with CaCO₃ particles in a water droplet, the conversion of PbSO₄ into PbCO₃ was confirmed by the change in morphology of the original particles to stick or needle form; the percentages of the chemical forms relative to the total Pb were determined by X-ray absorption near edge structure (XANES) analysis. Approximately 60–80% of PbSO₄ was converted to PbCO₃ after 24 h. A small amount of stick particles was detected when NaCl particles attached to PbSO₄/CaCO₃ particles were exposed to air with a relative humidity (RH) of 80–90% for 24 h. XANES measurements of the samples revealed that the molar percentage of PbCO₃ relative to the total Pb content was 4%.Field experiments were also conducted to determine the chemical forms of the Pb particles during the Kosa (Asian dust storm) event. Samples were collected from two remote sites in Japan and Korea. The mass size distribution of Pb aerosols collected in Japan was bimodal with two peaks in the coarse mode; the enrichment factor of Pb suggested that its source was anthropogenic. Pb L3 edge XANES measurements of both samples indicated that they had similar shapes. These measurements also indicated that the major Pb components for the samples collected in Japan were PbO, PbSO₄ PbCl₂, and PbCO₃, with molar percentages of 44%, 30%, 21%, and 5%, respectively. No significant differences were found between the component ratios of the samples collected in Japan and Korea, suggesting that definite transformation did not occur during the transport of the Kosa particles from Korea to Japan. On the basis of these observations, we postulate that the transformation process either occurred mainly before the particles arrived at Korea or did not take place after the particles left continental Asia.     

Synthesis of calcium phosphate hydrogel from waste incineration fly ash and its application to fuel cell

Waste incineration fly ash was successfully recycled to calcium phosphate hydrogel, a type of fast proton conductor. The crystallized hydrogel from incineration fly ash had a lower electric conductivity and a lower crystallinity than that from calcium carbonate reagent. However, the difference in electric conductivity between these crystallized hydrogels decreases with temperature. This was due to the presence of potassium in the incineration fly ash. The fuel cell with a membrane electrode assembly (MEA) using the calcium phosphate hydrogel membrane prepared from incineration fly ash was observed to generate electricity. The performance of this fuel cell was almost equal to that of a mixture of K₂CO₃ and CaCO₃ reagents; further, the performance of the former was superior to the fuel cell with a perfluorosulfonic polymer membrane at temperatures greater than approximately 85 °C.     

Characterization of trace elements in chicken and duck litter ash

For safe and sustainable management of poultry litter, it is important to evaluate and understand the chemical forms and concentrations of their constituent trace elements during treatment for disposal. This experiment was carried out to compare changes in metal (Cu, Mn, Zn, Pb and Ni) fractions in chicken and duck litter after incineration at temperatures ranging from 200 to 900 degrees C. The metals were stepwise fractionated into exchangeable, adsorbed, organically bound, carbonate precipitated and residual forms by extracting with 0.5M KNO3, de-ionized water, 0.5M NaOH, 0.05M Na2 EDTA and 4M HNO3, respectively. The content of total metal and other elements (i.e., Ca, Mg and K) were was also determined. Results showed an increasing trend in the total concentrations of metals with increasing temperature with higher amounts in chicken litter ash (CLA) than duck litter ash (DLA). Higher temperatures significantly reduced the levels of H2O-soluble Mn, Zn and Ni and enhanced those of Cu and Pb. The metal fractions extracted by EDTA and HNO3 increased directly with increasing temperature while the fraction extracted with KNO3 and NaOH decreased with ashing. For Cu, Mn, Pb and Ni, the amount extracted varied in the order EDTA>HNO3>NaOH>KNO3>H2O, but the absolute amounts differed between CLA and DLA. Peak concentrations of the total metals were achieved at the highest burning temperature. The amount of H2O soluble Ca and Mg decreased and K increased in both CLA and DLA with temperature. Total and exchangeable forms of cations increased with increasing temperature. Total Ca was highest in DLA, whereas total Mg and K were higher in CLA. This study indicated that incinerating poultry litter before soil application may have mixed effects on the vulnerable metal fractions by increasing or decreasing some fractions, depending on poultry type.