The environmental pollution by hazardous chemicals has been concerned. The discharge of hazardous chemicals into the environment must be prevented since it is difficult to specify the environmental influence by the chemicals. From the viewpoint of the health protection for employees, the handling of a lot of chemicals is regulated by various laws. However, the discharge of chemicals is hardly regulated. The chemicals on which the effluent standard has been already determined are only limited to a part of chemicals used in the laboratory. Even if the chemicals where the effluent standard is not set, the discharge of harmful chemicals must be avoided. In order to prevent the environmental pollution by chemicals, researchers themselves must learn how to manage the handling of used chemicals. Laboratories are, therefore, required to reduce the amounts of chemicals used and chemical wastes discharged. The chemicals should be used safely in the laboratory, in consideration of the environmental conservation and public health. Separate collection of chemical wastes at the generation source is the most important means for the safe treatment of the wastes. The basic principle of the treatment is to treat the wastes properly at the generation source. It is important for the original dischargers to recognize their responsibility as generators of the wastes.

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In Nagano Prefecture, in the period of January to March, 1997, sudden deaths of Bombycilla spp. birds happened in many places, amounting to 13 places with the total death of 187 birds. Of the places, Shimosuwa Town, Komoro City, and Iida City were selected to be inquired into the cause of the sudden deaths. In the case of Shimosuwa Town, the esophagus was choked with nuts of Pyracantha, and cyanide was detected in the content from the esophagus at 10.0 μg/g (average) and in the content from the stomach at 17.0 μg/g (average), suggesting that cyanide or nitrile glycoside would be one of the causes of the deaths. In the case of Komoro City, EPN, an organophosphorus pesticide, was detected from the content in the stomach at 5960 μg/g (average) and from the liver at 11.4 μg/g (average), suggesting that EPN would be a many cause of the death. In the case of Iida City no cause of the death has been known.

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We used intact cells and cell extracts to investigate the metabolic pathway of benzoic acid (BA) in Acinetobacter sp. strain ST-1, which dehalogenates 4-chlorobenzoic acid (4-CBA) hydrolytically and then mineralizes it via the β-ketoadipate pathway. Strain ST-1 degraded BA easily, yielding cis, cis-muconic acid and β-ketoadipic acid. A cell extract prepared from cells grown with BA transformed catechol into cis, cis-muconic acid and β-ketoadipic acid, but an extract of cells grown on 4-CBA lacked catechol 1, 2-dioxygenase activity. These results show that BA and 4-CBA are degraded in strain ST-1 by different pathways up to a common intermediate, β-ketoadipic acid, and that BA induces catechol 1, 2-dioxygenase. Therefore, the strain degraded BA via catechol to cis, cis-muconic acid and then to β-ketoadipic acid. The degradation pathways of BA and 4-CBA in strain ST-1 may be linked by the formation of β-ketoadipic acid, and then proceed along the β-ketoadipate pathway, even although the key intermediates before the ring fission are different, namely, catechol for BA and protocatechuic acid for 4-CBA.

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The genotoxicity of 2-amino-1-methyl-6-phenylimidazo [4, 5-b] pyridine (PhIP) was assayed by the wing spot test for detecting somatic cell mutations and the DNA-repair test for detecting DNA damage with Drosophila melanogaster. Although PhIP increased the frequency of small single spots in a dose-dependent manner in the wing spot test, no large single spots and twin spots were induced to a significant extent. In the DNA-repair test PhIP showed clear DNA-damaging activity. The DNA-damaging potency of PhIP was significantly increased when larvae were pretreated with β-naphthoflavone (BNF) 24-48 h after oviposition. Excessive reduction of the Rec^- male/Rec⁺ female ratio was also observed in ethanol-pretreated stock compared with stock not pretreated. These results indicate that alcohol and BNF, both enzyme inducers, enhance the in vivo DNA-damaging activity of PhIP.

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According to the official analytical method of methanol in commercial aerosol products, the concentration of methanol in their propelled solution was limited to less than 5%. The propelled solution was sampled by propelling aerosol into a flask for the evacuation of the propellant only. There was the possibility of occurrence of errors due to flying nebulized methanol in the procedure of propelling, or due to the high volume of dissolving propellant in the propelled solution. In this paper, after making some test aerosol products, the possibility of occurrence of error was discussed. The recoveries of methanol in the test aerosol products containing the ratio of 5% methanol/ethanol solution and isobutane by weight of 5 : 5, 4 : 6, 3 : 7 were high yields ranging from 97.5 to 99.2%. But those of 2 : 8 and 1 : 9 were 94.4% and 80.3% respectively due to the flying nebulized methanol. The detective yield of methanol in the propelled solution from the test aerosol products in the ratio of 3 : 7, after weighing the propelled solution by pouring it into a volumetric flask, with the propellant kept inside, was only 67.3%. The problem of dissolving propellant was solved by freeing the propellant while swinging the propelled solution flask on a water bath (20°C) within a tiny zeolite and weighing the propelled solution using a 1 mm i. d. tip dropping pipet. As a result of this experiment, it is suggested that the determination of methanol by the official analytical method may not be achieved in an aerosol containing high percentage of propellant.

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Sulfate ion in environmental water was determined by flow injection analysis using barium-dimethylsulfonazo-III complex as the reagent at a rate of 12 samples per hour. The linearity and sensitivity were investigated using ethanol-or dimethyl sulfoxide (DMSO)-water as solvent, respectively. DMSO-water medium was beneficial in the determination of a low concentration of sulfate below 3 mg l^-1. The calibration curve was linear in the range of 0.1-7 mg l^-1 with the correlation coefficient of 0.999. The detection limit was 0.1 mg l^-1. The relative standard deviation for 10 injections of SO₄^2- (5 mg l^-1) was 1.8%. The results of actual sample analysis agreed satisfactorily with those obtained by ion chromatography.

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