After a single oral administration of p, p'-dichlorobiphenyl (Cl₂-BP) or decachlorobiphenyl (Cl₁₀-BP) to male rate the distribution of each chlorinated biphenyl in several organs and tissues of these rats and excretion of each compound into urine and feces were investigated. Only a part of Cl₂-BP and Cl₁₀-BP administered to rats was absorbed through the gastrointestinal tract, and a small amount of each compound was excreted into urine, but most of both compounds were excreted into feces. Both chlorinated biphenyls were very quickly distributed in all rat tissues, especially in hypodermic adipose tissue and skin, and later, both compounds were very slowly excreted into urine. The biological half lives of Cl₂-BP and Cl₁₀-BP in the rat tissues were found in the range of 5.5 hr in lung to 26.4 hr in hypodermic adipose, and in the range of 83 hr in the liver to 513 hr in hypodermic adipose tissue. It was indicated that Cl₁₀-BC was retained for a longer period than Cl₂-BP in the rat tissues and it was suggested that the metabolism and excretion of Cl₁₀-BP in rat were extremely slower than those of Cl₂-BP.

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To investigate the effect of heavy metals on bone metabolism, cadmium acetate, lead acetate, and zinc acetate (0.89μmol as metal ion/100 g body weight) were intraperitoneally administered to rats 5 times every other day, and animals were bled 2 days after the last administration. The amount of metals that accumulated in the bone was about the same in the diaphysis and epiphysis of femur, and the amount of zinc was the largest, followed by lead, and that of cadmium was slight. This phenomenon was also observed after the administration of combined metals. The serum calcium concentration decreased significantly by the administration of cadmium or lead, compared with that of control, while it was not changed by zinc. The serum inorganic phosphorus concentration lowered significantly by the administration of cadmium, but increased slightly by lead and was not changed by zinc. The bone calcium concentration after cadmium administration decreased significantly in the epiphysis of femur but did not change in the diaphysis, compared with that of control. Lead administration markedly decreased the bone calcium concentration in both diaphysis and epiphysis of femur, white zinc administration increased it significantly in two parts of femur. Reduction of calcium concentration in the epiphysis caused by cadmium or lead administration was inhibited significantly by the administration of the combined cadmium, lead, and zinc. These results suggest that the effect of heavy metals on bone calcium appears specifically in response to the species of the metal, and that the specific action of each metal was modified by the administration of these metals in combination.

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As fundamental studies on chemical changes of organophosphorus pesticides during chlorination of the water, fate of 11 kinds of P=S type and 2 kinds of P=O type pesitcides in the chlorinated water was examined by thin-layer and gas chromatographic methods. Most of these pesticides examined were found to undergo a chemical change in water containing free chlorine as small as 0.1 ppm. Therefore, at a higher concentration of free chlorine, the P=S compounds were easily oxidized to P=O analogs in the water. However, P=O analogs were not detected from Dimethoate and Ethion in the water, while Dipterex, a P=O compound, underwent dehydrochlorination and rearrangement to form DDVP. Among the P=O derivatives formed from P=S compounds, Malaoxon, Paraoxon, and Diazoxon were comparatively stable in the water but Methyl paraoxon, Sumioxon, and Phosvel-oxon were markedly hydrolyzed and formed phenolic compounds in the water. Oxidation of P=O compounds with free chlorine was hardly influenced by the presence of magnesium, calcium and ferric ions less them 1.0 ppm but suppressed by a ferrous ion.

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Fundamental nature of the metallothionein fraction, effect of some compounds, and binding ability with various metals were examined in vitro, using the supernatant of liver homogenate of rabbits dosed with cadmium, and the following results were obtained. 1) Metallothionein fraction showed a strong resistance to heat and treatment with organic solvents. 2) o-Iodosobenzoic acid, sodium diethyl dithiocarbamate and ethylenediaminetetraacetic acid (EDTA) completely liberated cadmium and zinc in the metallothionein fraction, and D-penicillamine lowered zinc content to 88%. 3) Copper and silver underwent substitution with cadmium and zinc in the metallothionein fraction, and cadmium and mercury substituted with zinc. Lead liberated only zinc. Fifteen other metals examined did not show any effect. 4) Binding ability of metallothionein with metals decreased in the order of copper, cadmium, mercury, and zinc under the present experimental conditions. 5) Substitution of zinc in the metallothionein fraction with cadmium occurred even in as low a concentration of cadmium chloride solution as 8.9×10^-6M. There was no difference in the DEAE-cellulose column chromatographic behavior between the metallothionein fraction in which zinc was substituted with cadmium and that without such substitution.

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Changes of the activity of cholinesterase in mice treated with organic mercury compounds were examined. Diets containing ethylmercury chloride, methoxyethylmercury chloride, and propoxyethylmercury chloride were fed to mice continuously, and the first two compounds were intraperitoneally injected in a single administration. In continuous administration, cholinesterase activity in erythrocytes increased specifically in methoxyethylmercury-treated group. In all groups, cholinesterase activities in the brain were almost unchanged, while those in plasma increased and that in liver decreased, indicating that the increased activity in plasma may be derived from the liver. After a single injection, the activity of cholinesterase and other enzymes in serum increased, and then alteration of the cholinesterase activity in subcellular fractions of the liver was observed. It may be suggested, therefore, that organic mercury compounds have a toxic action of inducing disorders of cell function.

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Nitrate ion quantitatively interferes in the complexation of rhenium and dimethylglyoxime in the presence of stannous chloride. Therefor, this reaction can be used for the determination of nitrate ion. This method was applicable to the determination of nitrate-nitrogen in the range of 0.1-3.5 ppm. The standard deviation was ±3.0% on an average absorbance of the 2.0 ppm nitrate-nitrogen solution. Many coexisting substances except copper (II) did not interfere in the determination of nitrate ion. The procedure is as follows : A sample solution (10 ml) containing less than 35μg of nitrate-nitrogen is placed in a 50-ml volumetric flask, 1 ml of 35% hydrochloric acid, 15 ml of 99.5% ethanol, 3 ml of 200-ppm rhenium solution, and 4 ml of stannous chloride solution are added, and the mixture is allowed to stand for 25 min after shaking. To this mixture, 6 ml of 1% dimethylglyoxime solution is added, and the whole is brought to 50 ml with water. The absorbance of the developed color is measured at 442 nm after about 25 min.

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1. Cellulose, borosilicate glass and silica glass fiber thimble filters were achieved and inspected for the purpose of collecting micron order particles of dust in stack gas. 2. After several experiments, thimble filters of the size 25 mmD×90 mmH among other different sizes was shown most adequate for the practical use. 3. These thimble filters were revealed to have excellent characters compared to those of traditional filters.

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Metabolism of free-floating water plants depends largely on the water quality, i.e., substances in water. An experiment was undertaken to determine whether Eichornia crassipes SOLMS was useful as an indicator of water pollution with heavy metals or not. The plants were cultivated in nutrient solutions containing graded levels of cadmium, and the growing state, accumulation of cadmium, etc., were examined. Cadmium content in the plants increased with increasing amount of cadmium added to the nutrient culture solution. Total content of cadmium in the roots and leaves by adsorption and absorption reached 331-2420μg and 20.5-1010μg/g dry weight, respectively. The plant also showed an increase in heavy metals content when it was cultured in natural water and industrial waste water containing heavy metals.

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In most of chromium determination practices, acid extraction using hydrochloric acid, nitric acid, or sulfuric acid and nitric acid has been applied for environmental samples. Since chromium and most of its oxides are insoluble in acid, total chromium cannot be determined by the conventional pretreatment. The conventional acid extraction technique and alkali fusion technique, which was considered to completely recover chromium, were compared using chromium sesquioxide as a test compound. The alkali fusion treatment with sodium carbonate completely isolated chromium from chromium sesquioxide, while acid extraction using hydrochloric acid, etc., isolated little, even by addition of hydrogen peroxide solution. The acid extraction of collected dust and atmospheric dust gave a much lower chromium level than the alkali fusion. Thus, the alkali fusion technique using sodium carbonate, etc., is concluded to be one of the most suitable methods for the pretreatment of chromium determination of environmental samples.

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The lowering of blood cholinesterase in normal females was observed for a few days centering the ovulation day. Normal activity was found during the luteal phase. It is necessary for the determination of the correct blood cholinesterase activity in females to check her menstrual cycle at the time of examination.

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