Contamination of butyltin and phenyltin compounds in water, fish and shellfish from rivers and lakes was reviewed and the bioconcentration potential of tributyltin (TBT) and triphenyltin compounds (TPT) and their contamination in the wild fish and shellfish was evaluated. The use of organotin compounds such as TBT in antifouling paints was regulated in Europe, America and Japan in the years of 1982-1992. TBT concentrations after the regulations were gradually decreasing, for example, in water from Lake Lucerne in Switzerland, in mussel from Lynher River in UK and in fish from Lake Biwa. From the recent surveys in the years of 1998 1999, the TBT concentrations of water from rivers and lakes in Japan were not widely different from those in Canada, but higher TBT concentrations were detected in a part of the rivers and lakes in China. The contamination of TBT and TPT in fish and shellfish from rivers and lakes was mostly higher than that predicted by Laboratory bioconcentration factor (BCF) of the chemicals. From the comparison between Field BCF and Laboratory BCF, it was revealed that Field BCF was as large as or larger than Laboratory BCF for both TBT and TPT in fish and TBT in shellfish (mussel) . The one reason for the difference in fish is probably because Laboratory BCF is measured mainly via gill intake but Field BCF is derived from the accumulation via gill and by oral intake.

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While the hydrophobicity of a molecule principally determines the Bioconcentration potential of an organic chemical in fish, lack of bioconcentration would be also expected for a chemical with large molecular size due to its restricted permeability through biological membranes. In this review, the later factor relevant to the steric hindrance of a chemical in bioconcentration process is surveyed. It is clarified that a hydrophobic chemical is uptaken mainly via the transcellular pathway through respiratory cells in the secondary lamellae of gills, and thus, the steric size of a molecule determines the permeability controlled by the simple diffusion. There are many kinds of threshold values proposed for uptake in terms of the steric size of chemicals such as molecular weight (MW), molecular volume (MV), effective cross sectional diameter (Deft), and maximum diameter (Dmax) . Among them, precise predictions for lack of bioconcentration are represented when MW of 700 is assumed to be a threshold value for uptake of a variety of chemicals, such as the existing chemicals under the Chemical Substances Control Law Japan, etc. Thus, this MW of 700 could be one of the most practical, but still simple trigger values for the prediction of uptake limitation. When a chemical has high density atoms such as fluorine in a molecule with high substitution ratio, however, MW would overestimate the steric size of the molecule. In such a case, combined use of more direct steric descriptors such as MV would be needed to make a precise prediction.

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Characteristics of metal leaching and behavior of ionic species on surface of various metal plates were examined under three exposure conditions combining acid rain (acid fog or pure water fog) and atmosphere (gas and aerosol or gas alone) in an artificial exposure chamber.
The corrosion of Fe ion on a carbon steel plate resulted from aerosol by 80% and from gas by 14%. The Al ion on an aluminum alloy plate resulted from artificial acid fog by 51%, aerosol by 24%, and gas by 25%. The Cu ion on the bronze plate and on the copper plate, and the Pb ion on the bronze plate and on the lead plate were mainly due to artificial acid fog and gas.
Although the metal plates for the exposure of the present examination were about 12 times bigger than our previous examination, the concentration of various ion species in rain after touching to the metal surface did not differ very much except H⁺ ion decreased. Therefore the chemical reaction and physical adsorption in the corrosion products were not clarified. Many ions showed significant difference in the t-test between the blank water and the rain touched on the metal plate.

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A precise and simple method was developed for the determination of cobalt in environmental sediments. The sample was digested with HF/HN0₃/HC10₄, then cobalt was determined by inductively coupled plasma atomic emission spectrometry (ICP/AES) and inductively coupled plasma mass spectrometry (ICP/MS) . Determination of cobalt by ICP/AES was done at the 230.786nm emission line using In (325.906nm) as internal standard element and ⁵⁹Co was done using ¹⁰³Rh as internal standard element by ICP/MS.
Analytical results by ICP/AES and ICP/MS of 12 certified reference materials (CRMs: soil, sediment, rock and coal fly ash) showed good agreement with the certified or recommended values. However the results of two CRMs gave slightly lower values than the reference or recommended value probaly because of incomplete decomposition. Analytical results by ICP/AES and ICP/MS agreed each other in all of the 14 CRMs.
The precision for the determination of cobalt by ICP/AES and ICP/MS (relative standard deviation at 5 determinations) was 1.4-3.7 % when two CRMs were analyzed.
The concentration of cobalt in river sediments in Kanagawa prefecture were detected in the range from 24-30μg/g (average 27 μg/g) .

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In PCB treatment plant, it is necessary to monitor the performance of the plant in terms of both destruction efficiency and effects to the surrounding environment. Development of a rapid PCB analytical method is needed for the standpoint of safety management because the present official standard method takes several days for the analysis. In the present study, rapid analytical methods have been developed for PCB monitoring in organic solvent and wastewater.
The established method for the PCB in organic solvent consists of HPLC-clean up and largevolume injection GC/MS analysis, and could analyze samples within 2 hours with quantification limit less than 0.1mg/kg and C.V. within 5%. A combination of solid-phase extraction and precut GC-ECD was selected for PCB analysis in waste water with the performance of 2 hours analysis time, quantification limit less than 0.5μg/l and C.V. within 5%.
The developed two methods showed satisfactory performance in terms of both correlations with the standard method and applicability to the treatment plant.

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Effects of addition of activated carbon to diet including PCDD/DFs and non-ortho PCBs (Dioxins) on their accumulations of rats were investigated. Total body burdens of dioxins in control and sample rats were 62 % (6, 600 pg, 1, 000 pg-TEQ) and 4.8 % (480 pg, 30 pg-TEQ) of dioxins intake via diet (11, 000 pg, 1, 100 pg-TEQ), respectively, which indicates that the addition of activated carbon to diet prevented accumulation of dioxins in rat. Their preventional effects were remarkable for low chlorinated congeners of PCDD/DFs being highly toxic in liver. Specific accumulation patterns of dioxins in rat by addition of activated carbon were also found in some congeners of PCDDs and non-ortho PCBs, meaning that accumulation pattern of dioxins is affected by dietary component matrix. Furthermore, on basis of these experimental results, preventional mechanisms of dioxins accumulation by addition of activated carbon were discussed.

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The purpose of this study is the development of method for synthetically evaluating multiple estrogen-like compounds, present in river water and their effects on organisms. This paper explains an improved analytical method for quantifying the estrogen-like compounds. The present analytical method using LC/MS/MS is very simple and has a detection limit of 1 ppt for all the chemicals analyzed. The estrogen-like compounds present in the river water samples collected from Matsuyama, Japan were also quantified using this method. The estrogen like compounds, estrone (El), 17 β-estradiol (β-E2), estradiol-3-sulfate (E2-3S) and estrone-3-sulfate (E1-3S) were detected in the river water samples analyzed. The levels of these compounds are as follows: E1: n.d. to 24, β-E2: n.d. to 2.2, E2-3S: n.d. to 0.6 and El-3S: 0. 3 to 4. 1 ng/l. Bisphenols and alkylphenols such as bisphenol A (BPA: n.d. to 240 ng/l), 4-tent-octylphenol (4-tert-OP: 13 to 410 ng/l) and 4-nonylphenol (4-NP: 170 to 2800 ng/l) were also detected. These results show the presence of these man-made chemicals in considerably higher quantities in the river waters of Matsuyama, Japan, which can cause deleterious effects on organisms living there. The possible estrogenic action by these compounds on the organisms may be of great concern in future, indicating the necessity of continuous evaluation of these compounds and their estrogenic action in the organisms living in the rivers of the present study area and their ambient environment.

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Investigations on acidification of river waters were performed four times per year (total numbers of eight times) at 91 investigation points in four basin systems (Yamato river basin system (YaBS), Yodo river basin system (YoBS), Kino river basin system (KBS) and Shinguu river basin system (SBS) ) in Nara Prefecture over a period of two years from fiscal years 2001 to 2002. Acidification of river waters was not recognized in the four basin systems. However, electrical conductivity (E.C.) of waters from three investigation points in YoBS and four investigation points in SBS were below 5mS/m, and alkalinity of those from three investigation points in YoBS and three investigation points in SBS were below 0.2meq/l This suggests that waters at the points may be easily affected by acid rain. Accordingly, five investigation points (one investigation point in YoBS and four investigation points in SBS) may be easily affected by acid rain judging from both alkalinity and E.C. Long term trends of pH value of waters at those five points showed that two points (downstream of Fukatani river and Sakamoto dam lake) out of five had clear decreasing trends since middle of the 1970s.

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To develop the purification method for high accuracy and rapid analysis of dioxins, this study investigated the purification effects by heating chemical impregnated silica gel columns, i.e., AgNO₃ silica gel and H₂SO₄ silica gel. Removal effects of contaminants in crude solutions from flue gas and sediment treated with AgNO₃ silica gel at 60°C were highly efficient for sulfur compounds, but not for polycyclic aromatic hydrocarbons compared with those at room temperature (24±2°C ) . Purification by heating H₂SO₄ silica gel at 60°C was excellent in monoand poly-aromatic hydrocarbon compounds, and their removal effects were so far better than those at room temperature. In the case of chemical impregnated multilayer silica gel column, i.e., AgNO₃ silica gel/H₂SO₄ silica gel, the purification effects by heating at 60 °C were also highly efficient as compared to those at room temperature. These results indicate that the heating chemical impregnated multilayer silica gel column is useful for purification of sediment and biological samples enriched in sulfur compounds, and also for reduction of analytical time, amounts of solvents and contaminations in the capillary column and ionization spot.

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Changes in nonylphenol (NP) and bisphenol A (BPA) level in Kurose River were determined and their possible sources were discussed. NP level decreased after rain fall but returned the original level 2 days after rain fall, while BPA level transiently increased immediately after the rainfall, suggesting that NP is steadily supplied into the river, whereas BPA was accumulated on the surface of structure.

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Advanced drinking water treatment, which installed ozonation and activated carbon filtration into conventional treatment, has been in operation at all utilities of Osaka City (2.43 × 10⁶m³/day) since March 2000 to minimize formation of halogenated disinfection by-products (e.g., trihalomethanes (THM) ) . However, persons who brew tea or coffee from boiled tap water are still larger than those who directly drink water from the tap. We examined the changes in THM and total organic halogen (TOX) of advanced treated water (ATW) due to heating or boiling.
Total THM in ATW decreased with heating by using a kettle. Only chloroform was clearly generated when the water with chlorine was heated. THM were almost completely removed when the water was boiled for 1 min or less, regardless of using a kettle or an electric kettle. The reason of this is the reduction of precursors, intermediates and chlorine dose in the water due to the advanced treatment.
While TOX was almost constant in conventionally treated water (CTW) that was heated to boiling by using a kettle, 20% of TOX was removed in ATW. Subsequently, the removal of TOX was 50% for 5min and 60% for 20min of boiling both in ATW and CTW. For leaving after boiling for lhr, TOX of CTW increased again. Using an electric kettle, 40% of TOX of ATW decreased at boiling and 26% after keeping hot for 3hrs. When the hot water was reboiling, TOX did not increase.
Regardless of ATW, CTW or blend of each other, total THM calculated in terms of Cl equivalent could account for 32% of TOX. The removal of TOX from the heated water may be attributed to volatilization of THM and thermal decarboxylation of trihaloacetic acids.

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The safety of waste wood from construction and demolition processes must be improved so that wood chips derived from the waste wood can be recycled. Rapid assessment of the concentrations of heavy metals in these waste woods and classification of the woods according to concentration levels will facilitate recycling. In this study, X-ray fluorescence (XRF) analysis was found to be a useful method for rapid screening of metals in waste wood chips. Crushed wood, cellulose powder, and filter paper, which have a matrix similar to that of wood samples, were used as carriers for calibration standards. The metal concentrations in 36 waste wood chip samples determined by XRF using cellulose powder were closest to those determined by atomic absorption spectrometry, inductively coupled plasma-atomic emission spectrometry, or inductively coupled plasma-mass spectrometry. Cellulose powder was the most suitable standard for XRF analysis in terms of accuracy, ease of use, and consistent composition and particle size. Filter paper could also be used as a calibration standard for XRF after correction for layer thickness.

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