Up to now, toxaphene has not been registered in Japan as agricultural chemicals. The chemical is one of persistent organic pollutants (POPs), therefore, there is a trend of internationally controlling. In this paper, information on persistency of toxaphene and global polluted situations were arranged. Determination by gas chromatography-mass spectrometry (GC-MS) was also described. The composition of toxaphene, which persisted in the environment, was remarkably different from original technical toxaphene with the passage of time. For example, the main pathway of decomposition in soil was reductive dechlorination. Specific congeners in human milk were B8-1413 and B9-1679. It was thought that the congeners had strong persistency due to a stable bornane skeleton having no strain in sixmembered ring. Problems in GC-MS were as follows. Toxaphene was thermally much less stable; electron impact ionization caused complex fragmentation; and each congener varied extremely in the relative response factor using negative ion chemical ionization. In the future, the establishment of analytical system having the advantage of accuracy and of precision requires selective separation of enantiomers and synthesis of standard substances.

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We measured historical trends of dioxins and agrochemicals (DDTs, PCP and CNP) in five old Rice straws from tatami mats.
The measurement revealed that straw collected in 2000 contained DDTs and PCP The dioxin concentration corresponded to the amounts of PCP and CNP application. The highest total dioxin concentration and TEQ in straws were noted in the 1970 sample, 4300 pg/gdw and 6.1 pgTEQ/gdw respectively.
The source apportioning of PCDD/Fs in rice straws was analyzed by principal component analysis (PCA), correspondence analysis (CA), and multiple regression analysis (MRA) . PCA showed that the main sources of PCDD/Fs in straws were PCP CNP, and combustion (atmospheric deposition) . CA revealed the historical trend of the source, the possibility of an unknown source and the exposure pathway. MRA showed that the main source of PCDD/Fs TEQ was the combustion.
Finally, we estimated the contribution of PCDD/Fs in straws to dairy products (milk, cheese, and butter) and beef from the 1970s to 2000 in Japan. The estimation indicated that it did not contribute much to the remarkable decrease of TDI via dairy products and meat/eggs from the 1970s.

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This paper describes a study to characterize water quality problems in urbanized area in Tokyo, Japan. The toxicity of river water was measured at 37 sites in 29 rivers and streams by using two aquatic bioassays, Daphnia magna (Cladocera, Crustacea) acute immobilization test and the Microtox test. Measurement by the bioassays of the water samples showed persistence of toxicants in several river waters at acute level for D. magna and less toxicity for the marine bacteria Photobacterium phosphoreum (the Microtox test) . Determination of the water quality by chemical analysis revealed a wide range of contamination by pesticides, ammonia and anionic surfactant. Results indicate organophosphate insecticides to be predominantly responsible for the observed biological effects of river waters on D. magna. The insecticides concentrations in the river waters in Tokyo were substantial enough to cause a threat to the ecosystem. The use of daphnia assays has helped to focus attention on the use of pesticides in paddy field and other urbanized areas next to the rivers. The Microtox test results were inconsistent with the results of D. magna test, the pesticides concentration, or the BOD of water samples. The toxicant for the Microtox bacteria did not clarified.

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An analysis was conducted of the concentration and composition of dioxin (PCDD/Fs, Co-PCBs) and total PCBs (PCBs) in the sediment core of Tokyo Bay that area administrated by the Tokyo Metropolitan Government (35°30'19'' N, 139°50'58'' E) . Sedimentary records for these distributions were investigated over the years 1900-2000. It was revealed that contamination from PCBs and Co-PCBs has increased since the 1950's, reaching its maximum in the 1970's, and gradually decreasing after that. There is a connection to the time period between the peak concentration of PCBs and Co-PCBs residue and the maximum production level of commercial PCBs, with the results of principle component analysis of the congener profile indicating that the main source of Co-PCBs is a release of commercial PCBs. Total PCDD/Fs concentration levels were low before the 1950's, the homologue and congener profiles showing similarities in combustion and atmosphere. After that, the contamination level elevated rapidly, the profile suggesting that the cause of this rise was due mainly to the impurity of PCP and CNP. Recently, the levels of individual homologue and congener has decreased or leveled off, implying that pesticide impurities, especially PCP are continuously being released into Tokyo Bay.

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Plant damage, such as yellowing the outer rim of leaves, was reported in the vicinity of a steel-related factory.
Various investigations revealed that boron concentration was high (up to 550 mg/kg) in the affected leaves and in the flu gas from the factory where boric acid is used in the industrial process, indicating boron from the factory was the cause of plant damage. Moreover, the geographic distribution of affected trees and distribution of affected leaves within a tree suggested direct uptake of gas-phase boron compounds from atmosphere, although the chemical form of it has not been identified.
The technical advice to the factory led to process amelioration, which resulted in decreased boron emission in the flu gas.

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The photodegradation of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Coplanar-PCBs) was studied during a period of Soxhlet extraction with toluene under a fluorescent light. The photodegradation of PCDFs occurred remarkably under the condition of lighting-intensity of more than 1000 lx, but not occurred under the 600 lx. The main cause of degradation was an irradiation of ultraviolet ray emitted from a fluorescent light, involving the wavelengths of 313 nm and 365 nm. It was also found that the heating is another factor, which makes or promotes the degradation of PCDFs. These results mean that PCDFs are easy to degrade during a period of Soxhlet extraction with toluene under the laboratory light condition of a weak UV-intensity (ex. 5-10μW/cm²) .

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Supercritical fluid extraction (SFE) was optimized for the application to the extraction of several organochlorine pesticides in aquatic biological samples. SFE required 2 ml/min for supercritical fluid carbon dioxide flow rate, 0.70 g/ml for density (50 °C for temperature and 151 bar for pressure), and 7 % methanol for modifier. The extraction was completed for 40 min. After SFE, it was possible to be analyzed with GC/MS after clean-up with Florisil, packed in Pasteur pipette. From the comparison with ultrasonic extraction and SFE to mussels which were exposed to organochlorine pesticides, SFE seems to be applicable for the analysis of these pesticides in aquatic biological samples.

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In order to devise a simplified monitoring method of dioxins, the concentrations of chlorobenzens (CBz), chlorophenols (CPh) and carbon monoxide (CO) were compared to the concentration of dioxins. The concentrations of CBz and CPh, that are dioxin analogues, were approximately correlated to one of dioxins, and therefore it was considered to be efficient in monitoring dioxins for small size incinerator. A significant positive correlation (n=12, r=0.845, p<0. 01) was also found between concentrations of CO and dioxins at early time from ignition, indicating that indirectly measurement of CO by using smoke tester is useful to see if burning at early time from ignition is good or not.

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A sensitive and selective method was developed for the determination of amitrole in environmental water samples using by liquid chromatography/tandem mass spectrometry (LC/MS/MS) . Trace amount of amitrole was collected on Sep-Pak Plus AC-2 cartridge (AC-2 cartridge) and eluted with 10 ml of 25 % ammonia water/chloroform/acetonitrile (10/9/81) . The elute was separated by reversed-phase liquid chromatography and determined by tandem mass spectrometry. The collection efficiency of amitrole on AC-2 cartridge was from 97 % to 100 %. The detection limit of amitrole was 0.001 μg/l, and relative standard deviations of repeated analysis in 0.0025 μg/l-0.01μg/l of sample were in the range of 6.9-8.0 %. Amitrole was detected at 0.004 μg/l level in the river water and 0.6 μg/l level in leachate from waste landfills.

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Analytical methods of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs) in bottom sediments and aquatic organisms (shellfish) were evaluated. Two extracting processes were comparatively applied to air-dried river sediment; Soxhlet extraction with toluene (SXE) and alkaline digestion at room temperature followed by extraction with n-hexane (ALE) . The extracts were cleaned-up on silica-gel, alumina, and activated carbon columns in the same way.
Both processes provide almost the same distribution patterns of PCDDs/DFs homologues and congeners. For sediment analysis, therefore, ALE is considered to possess an almost equall extracting efficiency to conventional SXE.
However, the HpCDFs and OCDF data in duplicate measurements using ALE had a wider variation than using SXE. Moreover, the HpCDDs/DFs and OCDD/DF recoveries of internal standard substances labeled with ¹³C isotopes were dropped in ALE process. ALE process in organism analysis had also a same tendency of losses of internal standards. From an instability of highly chlorinated PCDDs/DFs to strong alkaline even at room temperature, alkaline treatment should be handled with care in PCDDs/DFs analysis.
Furthermore, actual PCDDs/DFs data of bottom sediment and freshwater snail taken at one site of a river were compared. The ratio of organism concentration (pg/g-wet) divided by sediment concentration (pg/g-dry) was used as a bioavailability index. It decreased, on the whole, with an increase in the substituted chlorine number of PCDDs/DFs, that is, highly chlorinated PCDDs/DFs were relatively more present in sediment rather than in organism. OCDD/DF showed approximately a tenth the ratio of 1, 3, 6, 8-TeCDD.

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Solid-phase high-performance liquid chromatography with electrospray mass spectrometry (LS/MS) was used in this study to analyze pesticides in river water. Polyacrylic resin was used for solid-phase extraction. Simulation was carried out to determine the optimal operation conditions for separation by liquid chromatography. A column for which high reproducibility of retention time even under 100 % aqueous gradient conditions was selected as the liquid chromatography separation column. Cone voltage at which maximal sensitivity was achieved was used for the mass spectrometry. Results of analysis by LS/MS of water samples collected from rivers in Hokkaido, the northernmost island of Japan, revealed seasonal variations in pesticide concentrations in river water and showed that concentrations of herbicides in the river water were generally higher than concentrations of fungicides and insecticides.

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