Firefighters are exposed to various toxic substances that result from combustion, the most widespread of which is carbon monoxide (CO). The occupational exposure to CO was investigated in 186 firefighters by measuring the CO concentration in expired breath after fighting fires and during ordinary conditions.
The test population was a random selection taken from members of the Tokyo Fire Defense Board who were engaged in fighting fires and the control population was also selected at random from students of the Tokyo Fire Academy. According to cigarette smoking patterns, the experimental and control groups were divided into three categories: nonsmokers, light smokers, and heavy smokers.
For each group, the nonsmoking group and the two smoking groups, the data presented in this study indicated that the CO body levels for firefighters increased remarkably after exposure to the atmosphere at the scene of a fire; that is, the CO breath level after firefighting was 17.2±8.9, 19, (ppm ±S.D., n) among the nonsmoking group, and 26.5±12.4, 40, among the smoking group. Three days after a fire, it was 3.4±1.3, 11, 15.3±8.1, 39, respectively. During routine performance of duties, the level of CO expired in nonsmokers was 5.5±3.2, 22, for test group, and 1.7±0.4, 14, for the control group. For light smokers the CO level was 18.9±6.3, 11, (≤20cigs/day), and for heavy smokers 25.9±9.0, 13, (>20cigs/day) for the test group, but 11.0±5.4, 29, (≤20cigs/day) and 18.0 ±6.2, 7, (>20cigs/day) for the control group, respectively.
Considering that for firefighters to perform their duties during a fire, the demand for oxygen of various tissue greatly increases due to high energy consumption, it is clear that the estimated dose of CO inhaled during firefighting reached harmful levels for proper functioning of the central nervous system and the myocardium.
This reporter suggests that those engaged in firefighting avoid cigarette smoking after a fire to prevent any further increase in the already high levels of CO that are present in their bodies.

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An analysis of mercury levels was carried out on dace of the species Tribolodon hakonensis (Günther) and T. ezoe Okada et Ikeda, captured in the Ishikari River and its seven tributaries between October 1975 and June 1978.
Results were as follows:
1) Two groups were differentiated, a group with relatively low mercury levels and another with relatively high mercury levels, in samples captured together at the same locations and of about the same size.
2) The authors believe that these different mercury levels are not due to the species or the sex of the fish but due to other factors such as migration, various levels of mercury in feed, and formation of sub-populations, each of which is composed of members of one age-class, to give a few possible cases.
3) Mercury levels of dace from the Peipan River were higher than those from other rivers due to vein of mercury located at the headwaters of the river.
4) The ratio of methyl mercury to total mercury in the fish was approximately 72% on the average, and there was no marked difference in the ratios found in each river.
5) The authors recommend a relatively loose method when comparing of fish mercury levels for various rivers instead of statistically stricter methods, as there is as yet relatively little ecological information on dace populations.
6) Similar results were found among crucian carp, Carassius carassius, captured near the mouth of the Ishikari in June 1978.

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Variations in the number of airborne, fallen and floor bacteria were examined in a model laboratory that was poorly ventilated with humans acting as bacterial carriers. The results obtained are summarized as follows:
1. There were no correlation between the number of airborne or fallen bacteria and physicochemical conditions such as temperature, humidity, air velocity, CO₂ or dust aerosols.
2. The number of airborne and fallen bacteria increased when persons entered the room, and decreased after they went out. On the other hand, an increase in the number of floor bacteria was observed after the subjects in it had left. Moreover it became clear that the number of bacteria was related to the atmospheric volume per unit person in the room.
3. It was found that nearly half the floor bacteria survived even after two weeks. This fact emphasizes the importance of the redispersal of floor bacteria by movement or walking when considering the origins of bacterial contamination of indoor air apart from those arising from the carriers.
4. By comparison with experiments in an air-conditioned room, it is assumed that ventilation reduces the increment of the number of airborne bacteria in a room.

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The Cornell Medical Index-Health Questionnaire (CMI) has been applied to psychosomatic medicine and preventive medicine such as the screening test of a general disease. The structure of the CMI and personality test questionnaires were examined by factor analysis. These questionnaires were self-administered by 155 female students ranging in age from 18 to 22. A total of thirty-seven items, including the 18 sections, A to R of the CMI, total “yes” responses of the CMI (TYR), 12 scales of the Yatabe-Guilford Test (Y-G Test), and 6 items of the Personality Inventory of Tokyo Institute of Technology (Personality Inventory), were analyzed by multiple correlation methods and the centroid methods.
Correlation coefficients calculated between two items in the same questionnaire method gave very high values. Correlation coefficients, with especially high values between two items using different questionnaire methods, were those of the N-R sections in the CMI, TYR, D, C, I and N scales in Y-G Test, schizothymia, hysterical tendencies, and nervousness in the Personality Inventory.
The multiple correlation coefficient between the TYR and personality was scored at 0.706, using Fukamachi's discrimination group III scored 0.983.
Seven factors were extracted by the centroid method. The first two factors were common for 37 items and had a pronounced contribution ratio amounting to 65.9%. The first factor was related to emotional stability, and the second factor was related to outside activity. These two factors of the TYR were accounted for 98.6% of cumulated contribution ratio. Therfore, it is believed that the TYR gives indexes of emotional stability and outside activity.

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To investigate the effects of air pollution on lung cancer, we carried out surveys of the rates for visits to physicians using receipts from the National Health Insurance Plan and of lung cancer mortality rates using death certificates.
The results were as follows:
1) The rates of visits to physicians for lung cancer were proportional to the degree of air pollution within a given area, but when compared with the control area, no significant difference was found.
2) Several years after air pollution increased markedly in Yokkaichi City, the lung cancer mortality showed rising tendencies, but no significant correlation between lung cancer mortality and the level of specific pollutants was found.
Compared to the control area, lung cancer mortality rates were slightly higher and increasingly younger ages of deaths from lung cancer in the polluted area were observed.
3) Furthermore, a higher death rate from lung cancer was found among those smoking more than 21 cigarettes per day than among nonsmokers.

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This study was undertaken to consider the species specificity of the effects of exposure to noise on adrenal function by applying the findings of experiments on animals to the case of human responses.
Humans and rats were exposed to a wide octave-band noise under different conditions of intensity and time, either continuously or intermittently. Under control conditions, the intensity of noise was 30dB (A).
In the experiment using rats, subjects were exposed to continuous noise at intensities of 60, 80 and 100dB (C) for 1 hour. Then, a time-series analysis of the 11-Hydroxycorticosterone (11-OHCS) concentration in the adrenal gland were carried out. Intermittent noise was administered at an intensity of 100dB (C) in ON-time and at 52dB (C) in OFF-time for 2 hours at 2, 6, or 20-seconds cycles, and the ratio of noise to pause was 1:1. Then, a time-series analysis of the 11-OHCS concentration in blood serum and the adrenal gland were carried out.
In the experiment using humans, subjects were exposed to continuous noise at intensities of 60, 80 and 100dB (C) for 1.5 hours. Intermittent noise was administered at 2-seconds cycle for 1.5 hours in the same manner as in the animal experiment. On both the exposures, time-series analyse of 11-OHCS in blood serum and urine were carried out.
The following results were obtained:
1) In rats, 11-OHCS concentrations in the adrenal were elevated in both the cases of continuous and intermittent exposure except in the case of intermittent exposure of 2-seconds cycles. The 11-OHCS concentrations in blood sera were elevated for all the exposures. These elevations were remarkable at the initial stage of exposure, although elevation levels were higher for cases of continuous exposure than for those of intermittent exposure.
2) In humans, no changes in the 11-OHCS excretion found in urine and in blood serum were observed under either the continuous and intermittent exposure.
From the above results, acceleration of adrenocortical function due to exposure to noise can be observed in rats but not in human beings. Thus, the reaction can be said to be species specific.

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The purpose of this study was to define respiratory function abnormalities in workers exposed to diatomaceous earth dust.
Flow-volume and spirometric tests were performed on 89 workers exposed to the dust and 40 healthy farmers who were used as a control group. All subjects were males ranging in age from 40 to 55 years.
The dust contained 66.5 to 74.1% Silicondioxide (SiO₂).
Workers were divided into two groups; one group included 20 workers with pneumoconiosis and 69 workers without as had been diagnosed by chest roentgenographic examination.
No significant differences in the mean values of age, height or weight were observed between the three groups.
The mean working years exposed to the dust of workers with pneumoconiosis was 25.5 years and that of workers without pneumoconiosis was 22.5 years.
There were no significant differences in smoking habits between the three groups.
The following results were obtained:
1. Significant differences were not observed in rates of coughing, expectorating sputum, wheezing or of shortness of breath among the three groups.
2. For the ten respiratory function indicators FVC, %VC, FEV₁, FEV₁%, PFR, V₅₀, V₅₀/ht, V₂₅, V₂₅/ht and V₅₀/V₂₅ differences were not significant between those workers with and those without pneumoconiosis.
3. Of the above ten indicators, mean values for V₅₀, V₅₀/ht, V₂₅ and V₂₅/ht for workers with pneumoconiosis were significantly lower than those for the control group.
4. Of the above ten indicators, mean values for FEV₁%, V₂₅ and V₂₅/ht for workers without pneumoconiosis were significantly lower than those for the control group. The mean value of V₅₀/V₂₅ was significantly higher for workers without pneumoconiosis than for the control group.
5. A comparison of the ten indicators between workers exposed to the dust and the control group, suggested that V₂₅/ht was the most useful in predicting respiratory function abnormalities.
6. To examine both workers and control groups, the most appropriate screening level of V₂₅/ht was 0.82L/sec/m.
These results demonstrated that workers with a long exposure to diatomaceous earth dust showed significant respiratory function abnormalities even though they had not been diagnosed as pneumoconiosis patients as such by chest roentgenographic examination.

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The purpose of this study was to define immunological changes in workers exposed to diatomaceous earth dust. Immunological tests were performed on 89 workers exposed to the dust and 40 healthy farmers who were used as a control group. Immunological tests included tuberculin skin tests (control subjects were excluded), CRP tests, RA tests, evaluations of serum protein concentration and its fractions, and serum immunoglobulin levels which are labelled IgG, IgA, IgM and IgD. All subjects were males ranging in age from 40 to 55 years.
Workers were divided into two groups; one group included 20 workers with pneumoconiosis and 69 workers without as had been diagnosed by chest roentgenographic examination.
The following results were obtained:
1. Significant differences were not observed in positive tuberculin skin test rates between workers with and without pneumoconiosis.
2. Positive rates for the CRP test of workers with pneumoconiosis was significantly higher than those of the other two groups.
3. Positive rates for the RA test did not show significant differences among the three groups.
4. For serum protein concentration evaluations and its fractions, mean values of β-globulin and γ-globulin were significantly higher and the A/G ratio was significantly lower among workers with pneumoconiosis than among the control group. The mean values of β-globulin for workers without pneumoconiosis were significantly higher than for those the control group. The mean value of γ-globulin was significantly higher and the A/G ratio was significantly lower for workers with pneumoconiosis than for those without it.
5. For serum immunoglobulin levels, the mean values of the IgG were not significantly different, the IgA were slightly higher, and the IgM were significantly higher for workers both with and without pneumoconiosis than the controls. The mean values of the IgD for workers with pneumoconiosis was lower than those for the other two groups.
6. There were no significant correlations between immunological parameters including serum protein concentrations, β-globulin, γ-globulin, A/G ratio, IgG, IgA, IgM and IgD, and V₂₅/ht as respiratory function parameters for both workers with and without pneumoconiosis.
These results demonstrated that some significant immunological changes appear in workers exposed to diatomaceous earth dust whether or not they are afflicted by pneumoconiosis. It should be noted that the pneumoconiosis, for those in this study afflicted with it was mild in all cases.

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Histochemical Studies on Rats Fed PCB and DDT.
Experiment 1.
Male Wistar rats were separated into three groups of 5 animals each. Group 1 was fed a commercial diet, group 2 was fed the same commercial diet and PCB, group 3 was fed the commercial diet and DDT.
After 30 days of these dietary regimens, all of the rats were sacrificed.
Liver weight increased significantly in groups fed PCB and DDT (groups 2 and 3). In rats fed PCB, the liver showed prominent dark brown pigmentation, but such was not manifest in rats fed DDT.
Fatty degeneration was observed in the livers of rats fed PCB and DDT upon histological examination.
Experiment 2.
Male Wistar rats were separated into four groups of five animals each. Group 1 was fed the synthetic diet, group 2 was fed the synthetic diet and PCB, group 3 was fed the commercial diet and group 4 was fed the commercial diet and PCB.
In rats fed the commercial diet containing PCB the liver showed prominent dark brown pigmentation which was identified histochemically as ceroid. The liver of rats given PCB fed the synthetic diet with PCB had a pale yellow color due to an accumulation of lipids.
This experiment indicates that toxic manifestations of PCB in rats differ significantly when different dietary regimens are followed.

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