Water has been used as a medium of disposal of agricultural, industrial and urban waste. The potential hazards of water-borne environmental chemicals sometimes include not only damage to the ecology, but well pose direct risks to human health. Polluted water may give rise to direct risks to humans through contamination of drinking water supplies and fish. Neoplasms of fish are histologically similar to those described in the mammals and classification schemes for human neoplasms have generally applied to fish neoplasms. Various types of tumor are inducible in experimental fishes by administrations of known chemical carcinogens. The studies on fish neoplasms from the view point of chemical carcinogenesis and environmental carcinogenesis were intiated during the course of the studies on hepatomas in hatchery-grown salmonids about 25 years ago. Since then, surveys and other studies on fish neoplasms in wild population have been elaborated in order to monitor and to detect water-borne environmental carcinogens at many sites in the world, especially in U.S.A. In the present reviews, reports regarding epizootic fish neoplasms in wild populations are summarized in a table and recent findings for which good evidence of a pollution etiology is presented in details. Those are case histories regarding hepatomas in sauger and walleye in a lake polluted by copper mining waste in U.S.A., hepatomas in tomcod at Hudson river estuary, hepatomas in English sole and in other fishes at Puget Sound, hepatomas in brown bullhead at the Black river estuary to the lake Erie, various types of neoplasms in the fishes at the Buffaro and Niagara rivers and eastern lake Erie, papillomas in black bullhead at a final oxidation pond of municipal sewage treatment plant, neuroblastoma in coho salmon at a hatchery supplied with chlorinated water and pigmented cell neoplasms in the croaker, Nibea mitsukurii inhabiting along the Pacific coast of Japan. On the basis of these facts the importance of researches regarding fish neoplasms are discussed from the view point of environmental carcinogensis.

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Neutron activation analysis is one of the best multielement analytical techniques and has been applied to the problem of forensic sciene. There are mainly two areas of application in forensic chemistry. The first is a multi-element analysis for the purpose of identifying a sample with its soure or origin by comparison of trace element patterns, for example, to determine the origin of opiums and cannabis. Trace characterization of a synthetic drug such as methamphetamine hydorchloride was achieved by this method and synthetic method of the drug was also assumed. Hair samples were analyzed for the purpose of monitering the environmental polution. In certain case, these data would be useful in the crime investigation. The second is its straightforward use as a method of trace element concentration determination, for example, in toxicology to detect arsenic or mercury in biological samples. It permitted interference-free analyses of trace amounts of halogens, germanium, and serenium. In the case work studies, detective analysis was another application of neutron activation analysis, because it could be determined both expected and unexpected elements in the physical evidence.

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The effects of asphalt tar and its components on the mutagenic activity of benzo[α]pyrene (B[α]P) were studied. The mutagenic activity of B[α]P was inhibited significantly by the addition of asphalt tar and its components especially by those containing neutral polycyclic aromatic hydrocarbon which was obtained by the fractionation according to the method of Hoffmann et al. The above effects seemed to be due to the inhibition of the activating enzyme of B[α]P and it was demonstrated that the activity of B[α]P-3-hydroxylase was inhibited strongly by the neutral polycyclic aromatic hydrocarbon fraction of the asphalt tar in a competitive manner (K₁=4μg/ml).

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By the collaborative study with Nagoya University Branch Hospital, we have found that naphthol AS (2-hydroxy-3-naphthanilide), an azoic coupling component, might be a causative agent of pigmented contact dermatitis from cotton flannel nightdresses (This journal, 32, 359 (1986)). In the course of the study, we developed a simple method for the determination of naphthol AS in cotton flannels. Naphthol AS could be extracted quantitatively from flannels under reflux with methanol, and purified by silica gel column chromatography by using ethyl acetate as an eluate. After methylation with diazomethane, it could be determined by high performance liquid chromatography (HPLC) by use of the following conditions : column, Nucleosil 50-5 (Nagel, 250 mm×4.6 mm i.d.) ; mobile phase, hexane-chloroform (12 : 5) ; flow rate, 1.0 ml/min ; detector, ultraviolet detector ; detection wavelength, 254 nm. Under these conditions, naphthol AS showed its peak at about 10 min, and its detection limit was found to be about 1 μg/g. Azo dyes in the methanol extracts were also determined by HPLC. Naphthol AS was detected in all cotton flannel nightdresses worn by the patients of pigmented contact dermatitis (contents : 850-11700μg/g, average : 5240μg/g). It was also detected in 5 kinds of commercial products, all of which were cotton flannel nightdresses dyed in the same manner as those worn by the patients (contents : 920-10200μg/g, average : 5760μg/g). It could not be found in other types of flannels. These results could support the idea that naphthol AS may be a causative agent of contact dermatitis from cotton flannel nightdresses.

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In order to identify a compound as a causative agent of contact dermatitis, the following requirements should be met : 1) The patient shows positive reaction to the suspected product. 2) The product contains the candidate compound. And, 3) the patient also shows positive reaction to the candidate compound. However, it is not easy to meet these requirements without co-operations between dermatologists and chemists. Recently, we have experienced four patients of pigmented contact dermatitis from cotton flannel nightdresses, and attempted to make clear the causative agent of these dermatitis by the combination of patch testing to the patients and chemical analysis of the flannels. The results obtained could be summarized as follows : i) In patch testing, all of four patients showed positive reactions to the cotton flannel nightdresses they had worn. ii) By the chemical analyses of these flannels, it was found that these flannels contained large amounts of naphthol AS (2-hydroxy-3-naphthanilide), an azoic coupling component (contents : 2900-11700μg/g). And, iii) the patients also showed positive reactions to naphthol AS in patch testing. Since the above results satisfied the requirements 1)-3), we could conclude that naphthol AS might be the causative agent of these dermatitis.

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A high-performance liquid chromatographic (HPLC) method for the quantitation of bromvalerylurea in biological materials is described. A cleanup of the samples for bromvalerylurea was achieved simply and rapidly by using Extrelut column with 1, 2-dichloroethane. The detection limit was 5 ng on octadecylsilated silica column with a mobile phase of acetonitrile-10 mM phosphoric acid (22 : 78) and an ultraviolet detector (225 nm). The calibration curve gave a good linearity over the range of 0.5-50μg/ml and 20-1000μg/ml using phenobarbital as internal standard. The method also showed a good reproducibility, the coefficient of variation being 2.0% for blood, 6.8% for urine and 2.7% for brain. The contents of bromvalerylurea in various tissues of a suicide cadaver could be determined with this method. This simple and rapid analytical technique could be useful for the detection of bromvalerylurea from intoxicated subjects in the field of forensic toxicology and emergency medicine.

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The enzymatic method was applied to the determination of glucose, fructose, and sucrose in fish paste foods such as "Kamaboko" and "Chikuwa, " Ten g of the sample was homogenized with water and made up to 200 ml with water. After centrifugation, 0.1 ml of the supernatant, which was filterd through the Toyo No 5C filter paper, was used to determine by the commercially available kid. The recoveries of the standard solution added to the sample at the concentration levels of 8 mg/g of glucose and fructose, and 16 mg/g of sucrose were 97.1%, 95.1%, and 91.3%, respectively. If the difference in the UV absorption was 0.1 on the calculation and this value could be defined as the lowest limit of the detection, their detection limits were 0.2 mg/g on glucose and fructose, and 0.4 mg/g on sucrose. The average concentrations of sucrose, glucose, and fructose in 34 fish paste foods purchased in Nara city were 49.8 mg/g, 6.6 mg/g, and 0.6 mg/g, respectively. The maximum concentration of sucrose was 113 mg/g.

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Smoked, dried bonito (katsuobushi) products, which are a typical class of Japanese food, contain mutagenic heterocyclic amines, 2-amino-3, 8-dimethylimidazo[4, 5-f]quinoxaline (MeIQx) and possibly 2-amino-3, 4, 8-trimethylimidazo[4, 5-f]quinoxaline (4, 8-DiMeIQx). It is now shown that mutagenicity possibly due to these mutagens is generated during the smoking-and-drying (baikan) of fresh bonito meat to prepare the products. Though the benzo[α]pyrene content in the tar portion of the intermediate sample of katsuobushi processing was 20-40 times higher than that in the residual meat portion, the major part of the mutagenic activity still remained in the bonito meat after removal of the peripheral tar.

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Amino acids are contained in various effluents and environmental waters and their COD values are adopted as a water pollution index. In this report, chemical oxygen demand (COD) originated from each amino acid was investigated. Acidic and alkaline COD determination was carried out with semimicro method using permanganate. The COD values of most amino acids were linearly increased with their molar concentration. The effect of AgNO₃ added into the reaction mixture was evidently recognized and the acidic values of amino acid, L-aspartic acid, increased by 27.5 times compared with those when it was not added. Big differences in COD values were shown among different groups of amino acids. Acidic COD values of amino acids did not reach the plateau values after 30 min's heating as the official method. In the alkaline method, COD values differed very little and showed higher values compaired with the acidic method. Heating time (60 min) was considered to be adequate. The decomposition rate to the theoretical values (complete oxidation) was 19.4% in the acidic and 43.9% in the alkaline method. Therefore the alkaline method will be utilized as a water pollution index of effluents containing amino acids.

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Collaborative studies on the determination of anionic surfactants in water were carried out to establish a method contributed to the Standard Method of Analysis of Hygienic Chemists authorized by the Pharmaceutical Society of Japan. The proposed methods were based on the colorimetric and atomic absorption spectrophotometric methods using bis[2-(5-chloro-2-pyridylazo)-5-diethylaminophenolato]cobalt[III]chloride (Co-PADAP) as a chelating agent. An adequate volume of a water sample containing 3-30μg (colorimetric method) or 0.1-5μg (atomic absorption method) of surfactants was taken in a separatory funnel. Two ml of 5 N-HCl or 2 N-H₂SO₄ and 1 ml of 0.04% Co-PADAP solution were added to the sample solution and mixed for a few seconds. After allowing to stand for 1 min, 10.0 ml of benzene was added to the solution and shaken for 1 min. The absorbance of the separated benzene layer at 560 nm was measured in the colorimetric method, while the layer was subjected to atomic absorption spectrophotometry when the concentration of surfactants in water was lower than 0.06 mg/l. When dodecylbenzenesulfonate (LAS) was used as a standard compound and recovery tests were performed for river water, satisfactory results were obtained. The limits to obtain accurate assayed values were 0.06 mg/l for the colorimetric method and 0.0001 mg/l for the atomic absorption spectrophotometric method, respectively.

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An indoor firework, so called "Cagar Ningyo", has been imported from Mexico. It has white stick-type accessaries consisting of mercury (II) thiocyanate (Hg(SCN)₂). When we set fire to the accessary, it decomposes extending brown-colored residuum like feces. By the thermal decomposition of Hg(SCN₂), some harmful gases such as mercury vapor (Hg gas), sulfur dioxide (SO₂ gas) and cyanate gas (CN gas) might be evolved. To estimate the risk from this firework, Hg gas, SO₂ gas and CN gas evolved from the accessary were determined by the modified "Standard Method of Analysis for Hygienic Chemists Authorized by the Pharmaceutical Society of Japan". As the results, maximum 157.0μg of Hg gas could be detected in the decomposition gas from 10 mg of the accessary. Therefore, if this firework might be used to play in a room of 22.4 m³ (6 Jyou), Hg concentration in the room air could reach at the level of 0.070 mg/m³, which might exceed the allowable level in the work place (0.05 mg/m³). Maximum values of SO₂ gas and CN gas detected were 2.26μg and 75μg, respectively, and predictive levels in the room might be much less than their allowable levels. We considered it undesirable to use this type of firework by the following reasons ; i) from the above estimate, we might be exposed to the high level of Hg vapor, ii) this firework itself or its residuum containing large amount of Hg might be discarded carelessly into the environment, and iii) it is dangerous to put such poisonous substances as Hg compounds near infants.

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