Compositions of chemical substances have characteristics depending on their sources. In the case of polychlorinated naphthalenes (PCNs), possible sources are the technical products in the past and the incineration of wastes. In this study, isomer compositions of PCNs in several sediment samples were compared with those of PCNs in source samples. The isomer patterns of PCNs in sediment samples were different from those in incineration samples but resembled with those in technical PCNs, showing similarity indices higher than 0.6, average 0.86. However, concentrations of isomers substituted on more than three within 1-, 4-, 5- or 8- positions were exceptionally lower in environmental samples than those in technical PCNs. This phenomenon was explained to be the result of biodegradation. Thus the PCNs in the samples measured here were considered to be originating mainly from industrial production of PCNs in the past.

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Monitoring of chemicals have been conducted in many places along Japan. An application of a statistical model for the prediction of the range of concentrations of chemicals in the water environment by utilizing these monitoring data was investigated in the present study. The quantification theory type II was applied for the analysis, and the six items were selected as the explanatory fractions, i.e., way of usage, way of consumption, water solubility, n-octanol/water partition coefficient, biodegradability, and load of chemicals. It was found by the analysis of monitoring data that load of chemicals, way of usage and way of consumption were the major determinants of the range of concentration in water environment, while the n-octanol/water partition coefficient was the major one in the sediment. The developed model was applied to the rest of data not incorporated in the analysis. The estimated values were within one to two orders of difference from the monitoring data.

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Characterization of polycyclic aromatic hydrocarbons (PAHs) and fused-ring heterocyclic compounds (FHCs) in coal tar pitch, ranging from C₁₂to C₄₅, were performed by the combination of mass spectrometric methods. Semi-volatile PAHs and FHCs were analysed by GC/MS method. Non-volatile, heavier PAHs and FHCs up to C₄₅, in coal tar pitch were analysed by liquid ionization (LI) MS by detecting their MH⁺ions.
The addition of methanol to the ion source of LI-MS was effective to distinguish between PAHs and FHCs. Most of LI-MS spectral peaks were identified by the molecular map constructed based on the regularity of the increment of molecular weights to be observed by adding 6 membered rings to the known PAHs and FHCs.
The above method was applied to the analysis of airborne total suspended particle, and could detect peaks corresponding to PAHs and FHCs, phthalic acid esters, fatty acid esters, fatty acids, and pesticide up to C₃₇by the LI-MS.

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Eight survey studies on the concentrations of fifteen species of anthropogenic organic compounds, including pesticides, organophosphoric acid triesters (OPEs) and synthetic perfume ingredients were carried out in Tamagawa River for the period 1993-1995.
During the study period, concentrations of pesticides, which are normally used in paddy fields, increased evidently in summer, while synthetic perfume ingredients showed a slight decrease in summer. Remarkable increases in concentrations of OPEs, perfume ingredients and some pesticides were observed invariably in the water at sites Haijima-bashi (S7) to Sekido-bashi (S10) along the course.
Increased amounts of these compounds between the points S7 and S10 matched well with the estimated loads of the compounds from tributaries and discharges of sewage treatment plants and municipal wastewaters in the region. Estimated loads for some compounds, such as TCEP, TDCPP, TPP, CAT, Galaxolide and Musk ketone, from the discharge of sewage treatment plants were larger than their load from the major tributary.

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Mutagenicity of twenty seven chlorinated aromatic hydrocarbons containing oxygen in their molecules were examined using preincubation method employingSalmonella typhimuyiumTA100, TA98, TA104 andEscherichia coliWP2uvrA/pKM101 with and without metabolic activation (S9mix) .
Chlorobenzoic acids, chlorobenzaldehydes, and chlorophenylacetic acids showed no mutagenicity under any conditions. Positive results were given in 13 chloride compounds, e.g., benzoyl chloride, with TA100 (0.8-2.7rev./μg) and TA104 (1.0-3.3rev./μg) with S9mix.

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PCDDs/PCDFs with four or more chlorine atoms, including non 2, 3, 7, 8-substituted isomers in fish and shrimp from Lake Kasumigaura were analyzed and their isomer profiles and biota-sediment accumulation factors were investigated. The concentration of total PCDDs/PCDFs and I-TEQ in fish and shrimp were 4.19-247.09pg/g (wet weight) and 0.18-9.85pg TEQ/g, respectively. The concentration of 1, 3, 6, 8 and 1, 3, 7, 9-TCDD were high in all samples and these two isomers accounted for more than 90% of the total TCDDs. The proportion of 2, 3, 7, 8-substituted isomers was 12.7-49.5% of the total PCDDs/PCDFs con-centration. 2, 3, 7, 8-Substituted isomers accumulated selectively in fish. The biota-sediment ac cumulation factors of PCDDs/PCDFs decreased with increasing log K_ow. Cluster analysis showed that the accumulation patterns from sediment to biota differed between crustaceans and fish.

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A new cytotoxicity screening method for the compounds impermeable through cell membranes was developed based on the combination of electroporation with the conventional incubation method using a cultured mammalian cell line, HL60. After optimizing the condition of electroporation, cytotoxicities of microcystins produced by cyanobacteria, DHBmicrocystin-RR and microcystin-LR, which are impermeable and did not show cytotoxicities by the previous HL60 incubation method, could be detected sensitively. On the other hand, a permeable compound, 2- (2-furyl) -3- (5-vitro-2-furyl) acrylamide (AF2), showed equal inhibitory effect on the growth of HL60 with or without electroporation, indicating that the method helps incorporation of the compounds into the cells without damaging the cells. The electroporation method will be effective as an alternative method for the toxicity evaluation by the primary culture of mammalian liver cells or animal studies.

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Concentrations of PCBs and activities of hepatic drug-metabolizing enzymes were measured in seven species of seabirds including Laysan Albatross (Diomedea immutabilis), Northern Fulmar (Fulmarus glacialis), Sooty Shearwater (Puf fines griseus), Short-tailed Shearwater (P. tenuirostris), Pomarine Jaeger (Stercorarius pomarinus), Black-legged Kittiwake (Larus tridactyla), and Red-legged Kittiwake (L. brevirostris) . PCB concentrations in pectoral muscle ranged from 0.010 to 2.8μg·g^-1. Twenty six PCB components, mainly IUPAC No.156, 118, 138, 180, and 99 were detected. The combined concentration of these five compounds accounted for more than 70% of total PCB concentration. Cytochrome P-450 contents ranged from 0.21 to 0.53 nmol·mg^-1protein. The ranges of activities (nmol product formed·min¹·mg^-1protein) of three drug-metabolizing enzymes, 7-ethoxyresorufin 0-deethylase (EROD), benzo [a] Jpyrene hydroxylase (AHH) and aldrin epoxidase (ALDE) in liver microsomes were 0.08-1.20, 0.01-0.36 and 0.11-1.63, respectively. The relationship between these activities and PCB concentrations were analyzed by multiple regression analysis.

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In order to investigate the sporadic transportation of Kosa aerosol to Japan from China, an effective discriminating method which is simple, rapid and highly sensitive was devised in characterizing the water soluble components of Kosa aerosol. The results indicated that concentrations of water soluble calcium (Ca²⁺) and strontium (Sr²⁺) in the particulate matter collected during Kosa phenomenon were higher than those collected during no Kosa phenomenon. It was also found that a ratio of non sea salt (nss) Sr²⁺to nss Ca²⁺in Kosa aerosol was more close to average Sr²⁺/Ca²⁺of the surface soils in Chinese loess and desert regions, in comparison with that of non-Kosa aerosol. These characteristics would be useful indicators to investigate the transportation of Kosa aerosol.

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The diurnal variations in direct mutagenic activity as well as the contribution of vitro aromatic compounds to direct mutagenicity were investigated by the response of strains TA98, TA98NR, TA98/1, 8-DNP₆, YG1021 and YG1024, using airborne particulate matter collected in Sapporo at 2-3h intervals on a winter day when there was relatively heavy pollution.
The diurnal variations in mutagenic activity for each strain were found to be dependent on human activities such as traffic and heating, and on meteorological factors such as atmospheric stability. Maximum values of mutagenic activity were 4-6 times larger than minimum values, and all the mutagenic activities showed similar patterns with two peaks at early morning and late night. Maximum mutagenic activity in TA98 was 131 rev/m³, which showed that urban residents, depending on the time of day, are exposed to considerably large amounts of airborne mutagens compared to residents of background areas (0.5 rev/m³) .
Mutagenic activity in all samples was in the order of YG1024>YG1021>TA98>TA98NR>TA98/1, 8-DNP₆, which strongly suggests that substances activated by 0-ATase contribute much more to direct mutagenic activity than substances activated by NRase. Moreover, the large decreases in mutagenic activity in TA98NR and TA98/1, 8-DNP₆compared to that in TA98 clearly indicate the importance of nitro aromatic compounds in direct-acting mutagens.

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