An analytical method for multielement determination of tarce elements in natural water (terrestrial water and seawater) by ICP-AES (inductively coupled plasmaatomic emission spectrometry) and ICP-MS (inductively coupled plasma massspectrometry) has been explored with the aid of chelating resin preconcentration, using Chelex-100 resin from Bio-Rad Laboratories (USA) . In order to evaluate the analytical reliability, the present chelating resin preconcentration/ analytical plasma spectrometry (ICP-AES and ICP-MS) method was applied to the determination of trace elements in river water certified reference material issued from the Japan Society for Analytical Chemistry and coastal seawater certified reference materialissued from National Research Council of Canada. The present method was alsoapplied to the analyses of Lake Biwa and Kagamiga-ike pond water samples. Furthermore, chemical speciation of trace elements in natural water by a combined system of SEC (size exclusion chromatography) / UV absorption/ ICP-MS (or ICP-AES) wasperformed after ultrafiltration preconcentration to elucidate the dissolved states or species of such trace elements. In ultrafiltration preconcentration, an ultrafiltrationfilter with the molecular permeation limit of 10, 000 Da in molecular weight (MW) wasused. As a result, it has been elucidated that most of trace elements exist as the largeorganic molecule-metal complexes (LOMMCs) in natual water. Such LOMMCs areobserved at Peak 1 (MW > 300, 000 Da) and Peak 2 (MW 10, 000-50, 000 Da) on the SEC chromatogram detected by ICP-MS. The fractional distributions of trace elements in the small-molecule, large-molecule and particle fractions of seawater werealso evaluated from the determination of trace elements in membrane (pore size 0.45, um) -filtered seawater, ultrafiltration (molecular permeation limit 10, 000 Da) -filteredseawater and particles remained on the membrane filter. In consequence, it wasconfirmed that LOMMCs of trace metals exist even in seawater. From these experimentalresults, a string-ball model is proposed as the dissolved species in naturalwater. The string-ball model is a formation model of LOMMCs with MW larger than 300, 000 Da, corresponding to Peak 1 in the SEC chromatogram, in which LOMMCs arecomposed of hydroxide colloides of Al and Fe as the cores and biogenic organicmaterials and diverse inorganic metal ions as the adsorbents on the cores, and such LOMMCs may grow their sizes to form the suspended particles in natural water. Onthe other hand, LOMMCs corresponding to Peak 2 in the SEC chromatogram may bemetal complexes of trace elements with biogenic protein-like compounds.

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This paper aims first to assess the damage of global warming on the world'svegetation over the next century, and second, to estimate the loss of economic valueof the forests in 2100 compared to 1990. Based on the IPCC IS 92 c, IS 92 a, IS 92 escenarios, it is clearly shown from these analyses that the following results are likely :(1) the forest ecosystem will disappear in 2%to9 % of the world's terrestrial areaby 2100. In addition, 3 % to 12 % of the world's forest area will decline. The damage will be particulary significant in the middle to high latitudes in the Northern hemisphere.(2) The loss of economic value of forest will amount to between 50 and 220 billion US dollars.

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This study provides an overview of the food supply and demand situation to the year 2010 in Asia based on the System Dynamics model. The amount of food demand will exceed the amount of food supply in India and China by 2010 if the exchange rate at the year of 1994 is to be continued and capital investment and the ratio of laboring population change as hypothesized below. Capital Investment : Part of newly obtained GDP is applied for investment. Newly obtained in "t year" will be invest as a Gross Capital Formation in "t+1 year". The relation between GDP and Gross Capital Formation is calculated. The growth rate of GDP is applied for estimating Gross Capital Formation. The following figures are considered to maintain until the year of 2010 as for GDP : Japan (1.2 %), India (3.2 %), China (7.0 %), Indonesia (6.4 %), Korea (4.3 %), Malaysia (4.3 %), Myanmar (3.8 %), Philippines (6.4 %) Sri Lanka (3.8 %), Thailand (4.3 %) and Singapore (4.3 %) on the basis of each country's currency. The Ratio of laboring Population : It is expected that the amount of labor affects the future amount of industrial production in Japan and Asian countries. In Japan, the shortage of labor force is presumable because of the rapid growth of aged population, whereas young labor force is abundant in Asian countries. The following figures are considered to maintain until the year of 2010 : Japan (2.2 %), India (2.2 %), China (2.0%), Indonesia (2.4 %), Korea (2.3 %), Malaysia (2.8 %), Myanmar (2.2 %) Philippines (2.2 %), Sri Lanka (2.2 %), Thailand (2.5 %) and Singapore (0.6 %).

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Photoinduced lesions in DNA, namely, cyclobutane pyrimidine dimers (CPDs) and pyrimidine- (6-4) -pyrimidone photoproducts [(6-4) photoproducts], in cucumbercotyledons exposed to solar radiation in Sapporo (N 43°) Okinawa (Iriomotejima is., N 24°) quantified by enzyme-linked immunosorbent assays (ELISAs) withmonoclonal antibodies specific to each type of photolesion. The amount of (6-4) photoproducts increased with increasing dosage of solar radiation (photosyntheticphoton flux, PPF). In contrast, the relationship between the amount of CPDs and PPF was not clear, probably due to the higher activity of light-dependent repair of CPDs ascompared with that of (6-4) photoproducts. The amount of photolesions in Okinawatended to be greater than in Sapporo at the same PPF dose probably due to the difference of ozone layer thickness, suggesting the likely future effects on plants of the increased UV-B radiation that will be a consequence of depletion of the ozone layer. Changes in the amounts of DNA lesions were different between CPDs and (6-4) photoproducts. CPDs decreased in the evening, but any noticeable decrease in the amount of (6-4) photoproducts was not observed, probably resulting from the differences in light-dependent repair activities of these lesions in cucumber cotyledons.

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Changes in salinity and sediment conditions, and recovery of macro-benthic fauna were investigated at three sampling sites with different water quality conditions before and after removal of the levee. After the removal, salinity and apparent redox potential in surface sediment in the inner Hirakata Bay significantly increased from mean 22.8 to 25.5 and from -150 to +95 mV, respectively, resulting in aerobic condition. At the same time dominant species in macro-benthic fauna changed from polychaetes Neanthes japonica, Capitellidae spp. to Bivalvia including Ruditapes philippinarum. These results suggest that increased exchange rate of water mass due to removal of the levee can result in improved habitat conditions for macro-benthic fauna and the supplement of planktonic larvae of Ruditapes philippinarum from the outside bay.

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Multielement determination of major-to-trace elements in leachate samples from industrial waste incineration fly ash (IWIFA) was carried out by ICP-AES and ICP-MS. Two kinds of IWIFA samples were leached with pure water and 0.1 M HNO₃ solution, and about 50 elements at the major-to-ultratrace level (mg/cm³ to ng/cm³ ) in the IWIFA leachate were determined with the relative standard deviations less than 10 %. Using the total content data of the elements in IWIFA samples, the leachabilities and enrichment factors of the elements were obtained. The leachability of each element was found to be strongly dependent on the final pH of the leachate. Moreover, the elements which exist as stable oxides in fly ash hardly leached. The leaching behaviors of the elements associated with final pH of the leachate were categorized into several groups, such as alkali elements, alkaline earth elements, major lithophile and major siderophile elements, trace lithophile elements, trace siderophile elements, oxoanion-forming elements, and trace chalcophile elements. These results suggest that the leaching behaviors of the elements in fly ash are significantly dependent on their chemical properties as well as their chemical species in fly ash.

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Infrared laser beam (CO₂ laser and Free Electron Laser) is irradiated on theOctachlorodibenzo-dioxins (mixture of OCDD and OCDF) of 20 ng in weight. Thoughthe decomposition by the irradiation of Free Electron Laser at the wavelength of 22μmor 25 μm is not observed, it is found that the dioxins are decomposed successfully byCO₂ laser at the wavelength of 10.6 μm (10W), and that the dioxins are decomposedexcept for Tetra through Heptachlorodibenzo-dioxins.

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We have studied environmental factors to limit the distribution of eelgrass (Zostera marina L.) by transplanting vegetative shoots of eelgrass at bare areas (0m, 1m and 2 m depth) in Zostera bed off Iwakuni airport. At 0 m control site in the Zostera bed, eelgrass shoot density decreased in a high wave season between spring and summer, showed different changes to the depth sites 1 m and 2 m. The annual mean irradiance at 2 m depth (near the deep edges of Zostera bed) was estimated to be ca. 3 E/m2/day, it was considered that the irradiance was a growth limiting factor of eelgrass. At 0 m transplanting site, all transplanted shoots disappeared because of disturbance by wave after the typhoon attack. But 1 m and 2 m transplanting sites showed almost the same changes in shoot density as control sites in spite of the typhoon. This suggests that lethal disturbance did not occurred at 1 m and 2 m trans-planting sites after the transplantation.And there was a difference in the shell appear-ance of the inside of sediments between the vegetated area and the bare area, although both physico-chemical characteristics at surface resembled each other. From these results, disturbance by wave, light intensity and physical characteristics of the sedi-ments were important as the environment factors to limit the distribution of Zostera beds.

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Organochlorine contaminants (OCs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloromethane and its metabolites (DDTs), hexachlorocyclohex-ane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) and butyltin compounds (BTs) were determined in three species of Alcidae (tufted puffin, hornbilled puffin and sooty guillemot) collected from coastal waters of Hokkaido, Japan. Mean concentrations of PCBs were the highest followed by DDTs, CHLs, HCB and HCHs, respectively. BTs levels in tufted puffin were comparable to concentrations of CHLs, HCHs and HCB, while concentrations of BTs in two other species were similar to those of DDTs. The residue levels of OCs, BTs and the estimated TEQ of coplanar PCBs in Alcidae from Hokkaido were one or two orders of magnitude lower than those in other fish-eating birds from other areas of Japan and North Pacific. As the estimated egg-TEQ of coplanar PCBs in Alcidae from Hokkaido were apparently lower than LOAEL (10pg/g TEQ) in chicken embryo, suggesting that reproduction of Alcidae from Hokkaido may not be affected by the current PCBs contamination.

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This study proposes the matrix of problem areas and safeguard subjects as a framework for comprehensively assessing overall environmental impacts. Such frame-work is intended for the use in valuation process in Life Cycle Impact Assessment (LCIA) and in priority setting of environmental policy. Through a series of workshops following "comparative risk" process developed by U. S. EPA, environmental impacts were sorted into the consistent and comprehensive matrix of 15 problem areas, and 4 safeguard subjects in Japanese standpoint. As a result from scoring process using the framework, the hazardous chemicals (especially in human health effect) was scored to be the most important by experts' judgement. In the last workshop, experts and citizens examined scoring process of 6 problem areas provided with scientific information by oral presentations and fact sheets. Through discussions among participants and iteration of scoring to share concern, scores between experts and citizens were not so different than generally expected.

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This is a report concerning a method to present horizontal distribution maps of biomass (carbon stock) and CO2 fixation of vegetation in some wide area, TOYOTA Foresta Hills. Reading the mesh-screened vegetation map and aerial photographs, the ratios of vegetational component in every mesh were deceided. As for the forest vegetations stem volume and its increment recorded in the Forest Register (data base for forest management planning) were avairable to estimate both total biomass and CO2 fixation by the calculations with some constant values by forest type. On the others than forest the suitable figures of biomass for each vegetation were employed, but their amounts of CO2 fixation were not counted because their carbon incomes as net production change to outgo as decomposition in a short period. Figures in each mesh were holizontaly mapped and summed up as the total amounts in the area.

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¹³⁷ Cs, ¹³⁴ Cs and ⁴⁰ K concentrations in 95 edible mushroom samples of 9 different species purchased in public food markets in Tokyo were analysed. ¹³⁷ Cs concentrations were X2.23-37.1 Bq/kg in dried mushrooms (dried Lentinus edodes and Auricularia auricula), and <0.223-7.76 Bq/kg in raw mushrooms. ⁴⁰ K were found in all mushroom samples but 134Cs was not detected. Annual intakes of 137Cs and40K (Bq⋅y^-1⋅person^-1) were estimated based on the statistics of mushroom consumption, which were then converted to internal dose equivalent using a dose conversion factor recommended by the ICRP Pub. 72. The average annual intake of ¹³⁷ Cs was 4.33-5.01 Bq⋅y^-1 'person^-1 (arithmetic mean, lower limit being the value when "less than detectable level" was taken as "0" and upper limit when it was taken as "minimum detectable level") and 3.76 Bq ⋅y^-1 ⋅person^-1 (geometric mean) which corresponded to the dose equivalent of 5.6×10^-5 -6.5×10^-5 mSv ⋅y^-1 and 4.8×10^-5 mSv⋅⋅y^-1 . The level was only 0.02-0.03 of the dose equivalent due to ⁴⁰ K received by ordinary Japanese individual.

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