The high mercuric level found in Menuke (red snapper) and Suzuki (common sea bass) from the Japanese Sanriku coastal waters was reported in 1973. Judging from the habit of these fishes, authors considered both the inshore and offshore to be polluted by mercury and embarked to confirm this possibility and to locate the central area of mercury pollution.
1) Inshore: The mercuric pollution level of 5 adjacent bays was studied preliminarily by survey of bottom mud, and then by a comparison of the mean mercury level of fish (Ainame, kelp greenling) with regressions of mercury level on the weight base. The results indicated all the bays to be polluted with mercury, and Kamaishi Bay to be most highly polluted among them.
2) Offshore: All fish and shellfish of 10 species, 6 miles off Miyako were found to be polluted with mercury and that bigger fish tended to show higher mercury content.
3) Comparison with other coastal areas: Upon comparing the mean mercury level and the regressions of mercury level per weight of fish (mackerel) in reference to its seasonal migration, the mercury pollution of this coastal area was found to be higher than that of other coastal areas.

View full abstract

It was considered that all the chlorine in Kanemi rice oils which caused the “Yusho” was derived from PCB, and the PCB concentrations were calculated from the concentration of total chlorine in the oils in 1969 to 1970.
However, in this study, the PCB concentrations in the oils were barely as 1/3 to 1/7 times as those which were calculated from the concentration of total chlorine. The difference between these two PCB levels suggests that unknown organochlorinated compounds will exist in large quantities in the oils. The oils were saponified, extracted with n-hexane, and the extracts were cleaned up by gel permeation chromatography and thin layer chromatography. Then, unknown organochlorinated compounds were analyzed by ECD-GC, GC-MS and neutron activation analysis. On 2% OV-210 column, the gas chromatograms of these compounds showed many peakes with later R. T. than that of PCT (Aroclor 5460). GC-MS analysis revealed that the compounds were composed of penta- to deca-chlorinated quaterphenyl, hepta- to nona-chlorinated quaterphenyl ether and penta- to octa-chlorinated terphenyl. Polychlorinated quaterphenyls occupied quantitatively the most of the compounds. The result of neutron activation analysis showed a surprising fact, i. e., in Kanemi rice oils, which were manufactured on Feb. 5, 9 and 10 in 1968, these unknown organochlorinated compounds were contained 1.1, 3.6 and 4.1 times, respectively, more than PCB amounts. Therefore, it became clear that the causal compounds of the “Yusho” were not only PCB and PCDF but also the higher molecular chlorinated compounds.

View full abstract

The purpose of this investigation was to determine chlorophenols residue in vegetables. 2, 4-Dichlorophenol, 2, 4, 5-trichlorophenol, 2, 4, 6-trichlorophenol and 2, 3, 4, 6-tetrachlorophenol were extracted with benzene by a improved essential oil distillator. Chlorophenols in benzene were extracted with 2% sodium chloride in 0.1M potassium carbonate solution. And chlorophenols were acetylated with acetic anhydride and extracted with n-hexane. n-Hexane solution was analyzed by gas chromatography using an electron capture detector.
The lower limits of detection in vegetable (50g) of 2, 4-dichlorophenol, 2, 4, 5-trichlorophenol, 2, 4, 6-trichlorophenol and 2, 3, 4, 6-tetrachlorophenol were 0.004, 0.002, 0.002 and 0.001ppm, respectively. The recovery of these chlorophenols ranged from 80 to 101% on addition of 0.5-10μg of chlorophenols on tomato.
Residue levels of chlorophenols in nine vegetables were analyzed. Chlorophenols were not detected in all samples.

View full abstract

Degradation of ethylenethiourea (ETU) and ethylenebisdithiocarbamates (EBDCs) under the various conditions of preservation in agricultural products were examined.
ETU applied on surface of spinach leaves was decreased by 96% at a room temperature of 20-25°C and by 73% at 5°C after 8 days respectively.
ETU in EBDCs applied on surface of spinach leaves was decreased by 92% at a room temperature, by 68% at 5°C after 8 days and by 57% under the sunlight after 5hr.
ETU was absorbed in spinach was stable comparing with that applied on surface of spinach leaves and decreased by 54% at a room temperature and by 30% at 5°C after 8 days.
On bottled fruits and vegetables the decomposition of added EBDCs was inhibited with increasing acidity. For instance, ETU in bottled tomatopuree added EBDCs in advance did not decrease even 200 days later.

View full abstract

A modified arabinose ammonium sulfate cholate agar (MAAC agar) plate procedure for isolating and enumerating Vibrio parahaemolyticus organisms in fish and shellfish was investigated. The medium consisted of 0.1% peptone, 0.1% yeast extract, 0.5% arabinose, 0.1% ammonium sulfate, 4.0% sodium chloride, 1.0% sodium thiosulfate, 0.1% sodium cholate, 0.004% bromothymol blue, 0.004% thymol blue, and 1.5% agar, with the pH adjusted to 8.6. Forty samples of shellfish and 30 samples of ice water used for soaking fish were collected from the Tokyo Central Wholesale Market in August 1977. Enumeration of V. parahaemolyticus counts in the samples was made by directly spreading each 0.1ml of the homogenates, the ice water samples and the appropriate dilutions on MAAC and TCBS plate media. The MAAC plates were incubated at 42°C for 18hr and TCBS plates at 35°C for 18hr. Presumptive V. parahaemolyticus counts, obtained from the numbers of yellow colonies formed on MAAC plates, ranged from 100 to 16, 000/g in the shellfish samples, and from 10 to 400/ml in the ice water samples. Out of 222 isolates from the MAAC media 185 (83.3%) were identified as V. parahaemolyticus, 26 (11.7%) as V. alginolyticus, and 11 (5.0%) as the allied organisms. Conversely, out of 121 isolates from TCBS media only 25 (20.7%) were identified as V. parahaemolyticus. MAAC agar plate procedure was found to be rapid and reliable for isolating and enumerating V. parahaemolyticus in various sea foods.

View full abstract

Fate of nitrate and nitrite in saliva of monkey was investigated by use of five monkeys (2.5-5.0kg) which were force-fed by a stomach tube with 4, 20, 40mg/kg of body weight of sodium nitrate solution at the ten-days intervals. As the results of this preliminary investigation, the monkeys could be grouped three different converters such as very good (M1), good (M2 and M3) and poor converter (M4 and M5).
To obtain more detail information about the reduction of ingested nitrate, further investigation was carried out on the good converter (M1), and the two poor converters (M4 and M5) of monkey as used for control. All monkeys used in this experiment were force-fed with 100mg/kg of sodium nitrate solutionby the stomach tube. Concentration of nitrate and nitrite in blood and saliva were successively calculated by the chemical procedure. Paralleled with this experiment, comparative survey for microflora of oral cavity of the monkeys was also conducted. Results of these studies were summarized as follows:
1) Nitrate concentration of blood in all the monkey tested peaked at 7hr after ingestion showing 180ppm. In the good monkey (M1), about 70ppm of the concentration was maintained for 48hr after administration.
2) Salivary concentration of nitrate in the good monkey showed in maximum concentration of 800ppm after 7hr, and the salivary concentration of nitrate was always kept in higher than that in blood. In contrary, the poor monkeys indicating rather lower concentration of nitrate in blood was observed.
3) Salivary concentration of nitrite in the good monkey indicated that a maximum concentration was 30ppm and 10-20ppm of nitrite was maintained in saliva for over 24hr. In the poor monkeys, however, no apparent correlation between ingestion of nitrate and formation of nitrite in saliva was observed.
4) A total count of bacteria and molds in oral cavity of the good monkey always showed a greater number of microbes than that of the poor monkeys. Streptococcaceae, Peptococcaceae and Bacteroidaceae were predominantly isolated from oral cavity of the good monkey. Of which, Bacteroides melaninogenicus was mostly common species among the microflora. Nitrate reducing species of bacteria belonging anaerobic bacteria, i. e., Bacteroidaceae and Veillonella seemed to be indigenous species in mouth of the good monkey.

View full abstract

[in Japanese]

View full abstract