Residue of PCB, DDT and HCH in several kinds of fish and shellfish from lakes and rivers in Japan was reviewed from the middle of 1970s to that of 1990s. There were differences among lakes (Lake Suwa, Lake Kasumigaura, Lake Shinji and Lake Biwa) or among rivers (Ado River, Kitakami River, Chikuma River or Toyohira River) in the concentrations of these chemicals, in the percentages of DDT and DDT metabolites in T-DDT and in the composition of HCH isomers.

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Water samples collected from TE river and K drinking water supply system which takes water from the TE river were analyzed by means of GC/ECD, in order to characterize and determine halogenated organic compounds. Trihalomethanes, haloacetones, haloacetaldehydes, haloacetic acids, halopropionic acids were found to be present in both river and drinking water. Among these halogenated organics, the highest concentration was observed for haloacetic acids in the river water while haloacetic acids and trihalomethanes as disinfection by-products were detected at higher concentrations in the drinking water. Brominated compounds, such as bromodichloromethane and tribromoacetic acid, were also detected at high concentrations in the drinking water, although these compounds showed very low levels in the river water.
These results were also compared with those observed for TA river and S drinking water which takes water from the TA river.

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A proposed passive sampling method was investigated for the determination of gaseous components such as nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone (O₃), nitric acid (HNO₃), hydrochloric acid (HCl) and ammonia (NH₃) in the air. The polluted atmospheric gases were sampled by the use of simple samplers composed of impregnated filters wrapped with a polytetrafluoroethylene filter. Then the trapped components were extracted with ultrapure water and were determined by ion chromatography (IC) for Cl^-, NO^-₂, NO^-₃ and SO^2-₄, and by Indophenol method for NH₄⁺. In the case of TEA sampler, the average concentration of NO₂ and SO₂ were determined with 0.63-1.8% and 4.4-10.5% relative standard deviations (RSDs) respectively, at atmospheric levels for 1-5 weeks exposure. With K₂CO₃ sampler, NO₂ and SO₂ were determined with 1.4-3.8% and 1.2-5.6% RSDs, respectively, and with TEA+ K₂CO₃ sampler, NO₂ and SO₂ were determined with 1.0-3.8% and 0.5-5.1% RSDs, respectively, at a similar field test. NaNO₂ sampler was applicable to O₃, SO₂ and HCl determination with 3.1-4.3%, 1.0-4.0% and 0-6.5% RSDs, respectively. Polyamide sampler was also applicable to HNO₃ and SO₂ determination with 3.5-6.0% and 3.9-6.7% RSDs, respectively. H₃PO₄ sampler was somewhat poorer precision with 6.9-26.7% RSDs.

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The incineration of wood wastes contaminated with chlordanes is reported. Tests were carried out by using combustion pipe with a electric furnace in laboratory. Under condition above 900°C with a residence time of 1 sec, the removal efficiency for chlordanes exceeded 99.9998% as calculated from residues at the levels of their detection limits. However, under thermal condition below 700°C, the destructions of chlordanes were incomplete.
Chlorinated hydrocarbons such as chloroprene, chloroform, 1, 4-dichloro-2-butyne and tetrachloroethylene were formed by the pyrolysis from chlordanes, and these compounds are considered to transform into chlorinated aromatic hydrocarbons such as chlorobenzenes, chlorophenols and PCBs by cyclization.

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Five recalcitrant Polycyclic aromatic hydrocarbons (PAHs) in ethanol were subjected to Fenton oxidation, followed by GC-MS identification of respective oxidation products, and their oxidation positions were compared to those predicted by Frontier electron density. Quinones were identified from the oxidation products. Except for fluorene, oxidation positions of quinone form products of acenaphthylene, anthracene, benz (a) anthracene, and benzo (a) pyrene were corresponded to predicted positions where Frontier electron density was high. From these results, it appears that calculation of the Frontier electron density of a PAH is a promising method for predicting the Fenton oxidation position.

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Mobility and leaching potential of Acetamiprid, (E) -N¹- [ (6-chloro-3-pyridyl) methyl] -N²-cyano-N¹-methylacetamidine (ATP) and its soil degradation products (degradates) in the field were investigated by the analysis of soil and water using two analytical methods. In addition to them, importance of microbial degradation of ATP in soil was evaluated by comparison of the degradation speed of ATP in sterilized and unsterilized soils.
The two different analytical methods were developed to determine the residual amounts of ATP and its soil degradates in water sample. One is a method for only ATP determination in water (P method), and another is a common moiety method for the determination of ATP and its soil degradates in water (C method) . The limit of detections (LOD) of the P method was 0.05ppb and fortified recoveries of ATP ranged from 82 to 98%. The LOD of the C method was also 0.05ppb and fortified recoveries of ATP and its soil degradates ranged from 78 to 90%.
ATP and its soil degradates were only detected in the upper part of the soil layer and they were not detected in the leachate passed through the soil layer. Only 1% of ATP applied was detected in run off water from the soil surface. Based on these results, it was estimated that leachability and run-off of ATP from soil surface was very small.
Further, it was considered that the degradation factor of ATP in soil was mainly due to microorganism.

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Estimation and evaluation of errors accompanied with calculation method of toxicity equivalency quantity (TEQ) of PCDD/PCDFs are discussed. Total TEQ and maximum error (bias+precision) are calculated by 6 different ways; namely TEQ for data above quantification limit (QL) and estimated TEQ for data below QL (3 ways), and TEQ for data above detection limit (DL) and estimated TEQ for data below DL (3 ways) .
Each calculation method is applied to estimate total TEQ for exhaust gas the concentration of which is changed by imaginary dilution and t-test is used to test a significance of the difference between total TEQ calculated by each method and the true values (concentration estimated from the original gas by correcting a dilution factor) . A good correlation between maximum error for each method and a difference of total TEQ from true value indicates that the maximum error can be used to evaluate the TEQ obtained by each calculation method.
The present evaluation method by maximum error is applied to both imaginarily diluted exhaust gases and real exhaust gases from various incinerators.
From the above discussion, calculation methods of TEQ have little effect on TEQ for samples in higher concentrations, but some methods give larger error at a lower concentration, indicating that TEQ obtained may be different from a true value.

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Mercuric ion volatilization by Chlorella spp. was investigated in inorganic media under light conditions. Volatilization of mercury was observed in all algal strains used. However, the amount of mercury volatilized was different from each other. More mercury was volatilized by the isolated strain in our university, C. sorokiniana, and C. vulgaris than by C. fusca var. vacuolata and C. kessleri. Taking the actual field conditions in account, effects of environmental factors such as pH, temperature, Cl^- concentration, and agitation of the media on the volatilization of mercury were also examined in this study.

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Atmospheric aerosol were collected by a low volume sampler for one and half a year during the period of 1997-1998 at the Miho Peninsula station in Shizuoka prefecture, Japan. A number of factories are located to the north and west of the sampling station. The station faces the sea in the south and the east directions. NH⁺₄, Cl^- NO^-₃, SO^2-₄ Na, Mg, Al, K, Ca, V, Fe, Cu, Zn and Pb in the samples were determined by an ion chromatograph and an ICP/AES. A comparison of the average concentration of those components in the samples with the average of 16 national stations in Japan showed that the atmospheric aerosol at Miho station contains higher concentrations of Na and V than the averages. Furthermore, various heavy elements in the sample showed high percentages of the water soluble fraction, such as Ca (97%), Na (96%), K (88%), V (86%), Zn (85%), Mg (83%), Pb (60%), Cu (53%), Fe (13%) and Al (12%) . The concentrations of water soluble fractions of V, Zn and Pb were found to increase when the wind came from the north. This suggests that those metals in the atmospheric aerosol come from anthropogenic activities. The water soluble Zn and Pb showed clear correlation with the monthly fluctuation of NH^-₄ and NO^-₃. The water soluble V did not correlate with other elements, suggesting a independent nature of a source of V from those of Zn and Pb.

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