Rats were injected intravenously with graded amounts of four metals ; Cd, Hg and Zn which induced metallothionein (MT) and Se which could not. They all contained their radioisotopes. The metal contents in the liver, its cytosol and each fraction of the cytosol obtained by Sephadex G-75 column chromatography were estimated by measuring their specific radioactivities. Hg incorporated into the liver accumulated in the cytosol especially in its MT fraction. Approximately 70% of Cd incorporated into the liver distributed to the cytosol and substantially Cd (more than 80%) in the cytosol distributed in its MT fraction. The 6-9% of Zn incorporated into the liver and 50-64% of Zn in the liver was found in its cytosol. About 2% of Se incorporated into the liver distributed to the MT fraction. On the other hand, from the fact that the high molecularweight protein (Fr. I) in the cytosol of rat liver was not induced by injected metals, the threshold quantities of injected metals for the production of MT were evaluated from the ratios of metal content in the MT fraction to that in the Fr. I. The threshold doses of Cd, Hg and Zn for the production of MT were thus calculated as 0.30μg, 40μg and 100μg per rat, respectively, while Se did not induce MT. From these threshold doses, the amounts of metals in the liver required for the production of MT were estimated to be 0.193μg Cd, 1.7μg Hg and 7.4μg Zn per liver. From these results it could be presumed that the production of MT in the liver is initiated after the metal content in the liver reached a certain level.

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In order to elucidate the behavior of chlorine in sea water, the chlorination and bromination of artificial sea water containing ammonia nitrogen were made. The concentration of residual oxidants (CRO) after chlorination for one hour increased proportionally with increasing the concentration of chlorine added, and reached to the maximum point (MP). The molar ratio of ammonia nitrogen versus chlorine at MP varied in the range of 1 : 0.87 to 1 : 1.29 with the concentration of ammonia nitrogen (0.7-2.8 mg/l). CRO decreased above MP, and arrived the minimum at the molar ratio of 1 : 2.5. The ammonia nitrogen almost disappeared. This ratio was considered to be the break point (BP). Monochloramine comprised much of the oxidants below BP, while free bromine was dominant above BP. In the bromination of artificial sea water, the molar ratio of BP was similar to that in the chlorination. However, the concentration of residual bromine after bromination for one hour below BP did not increase with increasing the concentration of bromine added, and MP was not observed. Below BP, monobromamine decreased rapidly with time and tribromamine only remained after one hour. The reaction of ammonia nitrogen with bromine was more rapid than chlorine. A similar behavior was observed in natural sea water containing ammonia nitrogen.

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Rat liver metallothioneins (MT) induced by 6 times injection (s.c.) of Cd, Cu or Zn (0.1 mg at each time) were isolated by Sephadex G-75 gel filtration. The metals were removed from MTs by treating them with EDTA. The thionein (t-MT) of MT treated with EDTA or Cd-MT was incubated with 2.5μmol each of Cd, Cu and Zn per mg of protein. The binding of these three metals to t-MT or Cd-MT was investigated in vitro. Further, the in vivo incorporation of each metal into hepatic MT of rats was also studied by injecting rats with 0.1 mg of Cd 6 times and then reinjecting (s.c.) with 10μmol each of Cd, Cu and Zn 24 hours after the final injection of Cd. MT was bound up to 8-9 g atom metals per mol of protein in vitro. The decreasing order of affinity of MT is considered to be Cu>Zn>Cd. The substitution of metals for the Cd-MT was observed. On the other hand, the amount of bound metals in the MT was increased by reinjection of each metal and the increments were based on the reinjected metals. The metals incorporated later are considered to be trapped by the present MT.

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A case of allergic contact dermatitis caused by heavy duty rubber gloves was reported. On patch testing with three kinds of gloves used by the patient and with various rubber additives, he reacted with only the rubber gloves and with N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD). These reactions continued for two weeks. Chemical analysis clarified that the gloves contained IPPD and styrenated phenol (SP) at levels of 177 and 1600μg/g, respectively. The analytical procedure was as follows : 1) extraction by shaking with acetone : chloroform (1 : 1) mixture at room temperature ; 2) fractionation by silica gel column chromatography, by using hexane, ether : hexane mixture of various ether contents (5, 10, 50%) and ether as eluants ; 3) clean-up by silica gel thin-layer chromatography, by using chloroform : benzene (10 : 9) mixture as a developing solvent ; 4) qualitative and quantitative analysis by gas chromatography (GC) on 3% SE-30 column and GC-mass spectrometry. From the results mentioned above, we considered that IPPD should be a causative agent in this case. Since some phenolic compounds have been identified as sensitizers and SP is a kind of them, SP is also anticipated to be causative. The possibility could not be ruled out, because SP was not applied to patch testing.

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Reactions of chlorine and naphthols, as model compounds in aquatic environmental pollutants, in dilute aqueous solution were investigated by means of gas liquid chromatography (GLC) and mass spectrometry (MS). Naphthols consumed a large amount of chlorine at neutral pH during the first 30 min, followed by much slower secondary reactions. After reacting for 24 h at 20°C, chlorine demands of α-and β-isomers were 14.2 and 7.7 mol of HOCl/mol of compound in the buffered water at pH 7, respectively. However, these demands lowered to 8.0 and 4.4 in the non-buffered water, which was characterized by a decrease in pH during the reactions. GLC and MS analyses for ether extracts obtained from the chlorine-treated naphthol solutions indicate that the reactions involve chlorination to mono-and dichlorinated naphthols (A), oxidation to chlorinated naphthoquinones (B), oxi-degradation of the compounds B to the aromatic carboxylic acids and dimerization of the compounds A and B. In addition, it was found that the reactions were dependent on the solution pH, molar ratios of HOCl/compound, and reaction time.

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A method for the determination of 4, 6-dichloro-7-(2, 4, 5-trichlorophenoxy)-2-trifluoromethyl-benzimidazole (DTTB), which was used as a mothproofing agent in wool fabrics, was developed. DTTB was extracted with ether from 10% sodium hydroxide solution of wool fabrics, and the purification of the extracts was accomplished by silicagel column chromatography. The purified extracts were dissolved in methanol containing internal standard and then measured by reversed-phase high performance liquid chromatography on LiChrosolb RP-18. The solution of methanol-water-acetic acid (90 : 9 : 1) was used as the mobile phase and chrysene was used as an internal standard. Detection was accomplished with fluorescence spectrophotometer operated at λex=300 nm and λem=360 nm. Recoveries averaged 84.9% and 99.4% for the untreated carpet to which 2.3μg/g of DTTB was added and the processed fabrics treated with Mitin LA, which is the market products of DTTB, respectively.

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Mutagenicity of ether-extracted fractions obtained by the reactions of naphthols and hypochlorite in dilute aqueous solutions was investigated by using Ames Salmonella typhimurium TA98 and TA100 strains. No mutagenic activity against TA98 and TA100 strains both with and without rat liver homogenates (S-9) was observed for the ether fractions obtained from α-and β-naphthols (NT) treated with chlorine at low HOCl/NT ratios, although these fractions were toxic toward the tester strains. The ether fraction obtained from β-naphthol treated with chlorine at high HOCl/NT ratios however, exhibited the mutagenicity against the strain TA100 without S-9 Mix. The compounds identified in the ether fractions : chloronaphthols, chloronaphthoquinones, and other carboxylic acids, did not exhibit the mutagenicity toward TA98 and TA100 strains in the presence and absence of mammalian metabolic activation. No chemicals which could be determined to be responsible for the mutagenicity of the reaction mixture was isolated ; it is, however, obvious that certain materials were produced by the reaction of β-naphthol and chlorine in dilute aqueous solutions.

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Chromium is a biologically significant metal which is present in the environment. This paper describes a study of seasonal variations in the amounts of chromium and several other components in deposits regularly collected from the air in Kanazawa city during one year. The concentration of chromium amounted to 0-1.1 ppb and was comparable to those of chromium in the sea and natural waters. Several other components in the deposits were also determined and correlations among the components, including chromium, were investigated. The seasonal variation of chromium in the deposits collected at this spot showed that the meteorological conditions considerably influenced the profile of chromium in the deposits. Another important factor is artificial sources such as fuel combustion for industrial and domestic purposes. Among the components in the deposits, magnesium and chloride contents were fairly closely correlated with chromium, and sulfate was also correlated with chromium though less closely. The possible origin of chromium in the deposits is discussed.

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