Scalp hair sample were collected from 20 gray-haired males and 7 gray-haired females. Two hair samples, one each of dark hair and gray hair, obtained from each individual were selectively analysed for organic and inorganic mercury concentrations. The following finding were made:
1) In both sexes, total and organic mercury concentrations were significantly higher in gray hair than in dark hair but no difference was observed between dark hair and gray hair for the concentration of inorganic mercury.
2) For males, no significant differences between dark hair and gray hair were found for total, organic or inorganic mercury concentrations. On the other hand, gray hair had significantly higher levels of total, organic and inorganic mercury concentrations than dark hair in females.
3) When comparison was made between the sexes, total, organic and inorganic mercury concentrations were significantly higher in males than in females for dark hair. For gray hair, however, significantly higher levels of total and organic mercury concentrations, but not of inorganic mercury concentrations, were found in males.
4) The proportion of inorganic mercury to total mercury was higher in females than in males for both dark and gray hair. It was also higher in gray hair than in dark hair for females.

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Dibutyltin compounds (DBTC) in polyvinyl chloride resin (PVC) were examined by capillary gas chromatography using a flame photometric detector (FPD).
DBTC was extracted with a carbon tetrachloride-methanol (2:1) mixture under reflux. The extract was mixed with a hydrobromic acid solution. Dibutyltin dibromide was converted to dibutyldipentyltin (DBDPeT) by the Grignard reaction with pentylmagnesium bromide and then subjected to gas chromatography.
A linear correlation between the amount of tin and peak height was observed in the range of 7.8 to 250pg of tin on log-log paper. Recoveries of DBTC added to PVC were 92.6-108.1%.
The results show that this procedure is more useful and sensitive (the detection limit is 3-4pg, as tin) than previous methods reported.

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The present study was conducted to get information necessary for the disposal of domestic waste water by soil permeation. The clarifying ability of soil was examined by conducting laboratory experiments using soil columns and making inquiries about practical disposal facilities based on soil permeation using trenches. In the column experiment, soil columns were prepared by packing polyvinyl chloride pipes with volcanic-ash loam, river sand, or an equivolume mixture of both, and secondary effluent of domestic waste water was poured into each soil column at a daily rate of 100l/mm². In this experiment, loam and sand loam, both containing fine silt and clay, gave BOD removals of over 95% when the influent BOD load per 1m³ of soil was less than 10g/d and gave the coliform group removals of 100% when the influent coliform group load per 1m³ soil was less than 10⁹/d. Loam and sand loam gave T-P removals of over 90%. The P adsorption capacity of soil was limited to less than 12% of the absorption coefficient of phosphoric acid. All the soils gave low T-N removals, mostly less than 50%. The trench disposal gave high removals of 90-97% for BOD, 90-97% for T-P, and 94-99% for the coliform group but low removals of 11-49% for T-N, showing a trend similar to that of the column disposal. Thus, we can roughly estimate the effectiveness of actual soil permeation disposal from the results of the column experiments. In the waste water permeation region, the extent of waste water permeation exceeded 700cm horizontally from the trench, but the waste water load within 100cm laterally from the trench occupied 60.3% of the total. The concentrations of T-C and T-N at almost all observation spots in the permeation region were lower than in the control region, and were not caused to accumulate in soil by waste water loading. In contrast, T-P was accumulated concentratively in the depth range from 50-100cm right below the trench. The conditions for effective disposal of domestic waste water by soil permeation have been estimated to be: (1) the soil should contain more than 30% silt and clay, (2) the absorption coefficient of phosphoric acid should be more than 1000, (3) the permeation rate should be 1.0-1.8mm/min, and (4) the soil volume to be permeated should be more than 6.86m³/person.

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In order to assess the effects of noise on sleep, the authors have developed a microcomputer system which determines the sleep stage based on an all-night EEG (electroencephalogram), rapid eye movement and an EMG (electromyogram). All the polygraphic parameters for each epoch (including spindle, rapid eye movement, alpha and delta waves, and amount of muscle tension), which are necessary to determine the sleep stage, were determined by a microcomputer using a digital data processing program. Recognition of EEG waves is based on Fujimori's method with some modifications. The rules of Rechtschaffen et al. were adopted for judging sleep stage with a slight modification.
Data were obtained from six healthy students of a university. Each student was polygraphed for five to six nights under various conditions of noise exposure. Judgements of the sleep stage were made by two medical doctors. Using randomly selected 10 nights' data, the agreement between judgements by the microcomputer system and by the doctor was 77%. The percentage of agreement increased to 84% for the epochs in which the two doctors agreed.
It takes about one hour to determine all-night sleep stages by this system.

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The effect of steady noise on sleep was examined experimentally for 24 nights by sleep polygraphy of a twenty-eight-year-old man. The parameters used for sleep polygraphy were sleep stage, sleep latency, frequency of sleep stage shift per hour, average sleep depth, the gradient and intercept of a regression line of sleep depth against time, and subjective sleep. The sleep stage was judged and estimated based on the criteria of Rechtschaffen & Kales by the authors' original system using a microcomputer. For the calculation of sleep depth at a given time, stages W (waking), 1, REM, 2, 3 and 4 were weighted to be 0, 1, 1.5, 2, 3 and 4, respectively. Sleep parameters were compared between the data of non-noise and noise-exposed nights. The noise exposure was overnight stationary pink noise of 40, 50 and 60 dB (A).
General findings were a decreased REM stage, an increased stage 2, and deepened average sleep depth of the 60 dB (A)-night sleep compared with the control and 40 dB (A) exposure nights. When the control nights were excluded and parameters were compared between the three levels of stationary noise exposure, stage 2, the intercept of the regression line, and average sleep depth were increased almost in proportion to the increased noise exposure. In contrast, sleep latency, frequencies of sleep stage shift, stages W, 1, 3, MT, and REM, as well as the gradient of the regression line were decreased with increased noise exposure.
Although the decrease of stage 3 and REM at 60 dB (A) indicated the possibility of sleep disturbance, the subject continued to sleep well as indicated by the shortened sleep latency and deepened average sleep depth even under the environment of 60 dB (A) stationary noise exposure.

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One healthy twenty-eight-year old man was exposed allnight to intermittent, rectangular pink noise of 5 and 10 seconds' duration 9 times per hour. The peak levels prepared were 40, 50 and 60dB (A). One level of the noise was exposed throughout a single night. Ten non-exposed control nights were also prepared. The sleep electroencephalogram was analysed by a microcomputer system of the authors' devising.
Increases of sleep latency and stage W, and decreases of the REM stage and mean sleep depth, especially in the early sleep hours, were confirmed in the sleep polygraph of the 60dB (A) exposure but not in that of the control, 40, and 50dB (A) exposures. It was concluded from these results that the intermittent 60dB (A) pink noise exposure clearly disturbed sleep, and that the threshold of the effect shou

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By using the STAI developed by Spielberger et al. we have investigated the validity and reliability of two scales, that is, State Anxiety (A-State) and Trait Anxiety (A-Trait), and at the same time have examined them under various conditions.
The results obtained are as follows:
1) As a result of factor analysis concerning 40 items of the STAI used in this research, we have confirmed that both A-State and A-Trait have independent factor structures of their own, and that the items of the scales also carry their own validity.
2) After due consideration of the test-retest reliability of the two scales, we have found that A-Trait has rather high stability. Moreover, we have noticed that Cronbach's alpha coefficients, which show the reliability of the two scales, are high. In consequence, we have confirmed the high reliability of the two scales.
3) In comparing the scores of A-State and A-Trait obtained from young healthy people with those from healthy aged people, we have noticed that the aged get low scores on each of the two scales, and that each score distribution shows an excellent fit to the normal one.
4) We have found that A-State scores go up significantly when people are in a condition of emotional stress, but that there is not any change of A-Trait scores.
5) We have observed a significant increase of A-State scores at each noise level over 75dB(A).
From the above-mentioned results, we have reached the conclusion that the STAI is very valid and reliable, and that the A-State scale, especially, is a very good indicator of men's psychological states under conditions of temporary stress.

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Urinary metabolites and biological half-life of chlorpyrifos (O, O-diethyl-O-3, 5, 6-trichloro-2-pyridinyl phosphorothioate) were investigated. Male Wistar rats weighing 200g were intraperitoneally injected with chlorpyrifos at a level of 0.2mmol/kg body weight. Both chlorpyrifos and 3, 5, 6-trichloro-2-pyridinol (TCP) levels in blood showed maximum values at 5h post-injection, and then decreased rapidly. Biological half-lives of the blood chlorpyrifos and TCP were estimated to 8.15 and 24.66h, respectively. Urine was collected for 96h post-injection and hydrolyzed with 4N HCl or β-glucuronidase with sulfatase, and TCP released was determined. Urinary excretion levels of the acid hydrolysisreleased TCP and the enzyme hydrolysis-released TCP accounted for 86 and 54% of chlorpyrifos administered, respectively. Urinary excretion levels of alkylphosphates for 96 h post-injection were analyzed. The excretion levels of diethylthiophosphate (DETP) and diethylphosphate (DEP) accounted for 45 and 15% of chlorpyrifos administered, respectively. These results indicate that 1) about half of the chlorpyrifos administered was directly hydrolyzed to DETP and TCP, 2) 10 to 20% was hydrolyzed to DEP and TCP after the oxidation to chlorpyrifos oxon, and 3) about 30% was dealkylated to TCP-phosphate after the oxidation.

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This paper presents the results of experiments in which we measured humidity and temperature changes that took place in different layers inside and on clothing. The experiments were conducted during rest, exercise, and recovery. During each experiment, subjects wore one of three kinds of outerwear made of three different materials, respectively. These materials were nylon taffeta (N), nylon taffeta-Goretex-nylon tricot laminated fabric (G), and polyvinylchloride-coated plain cotton fabric (V). The subjects wore an undershirt and a T-shirt under the outerwear.
The humidity and the temperature were measured in the following parts of each subjects' back: (1) the layer between the subject's skin and the undershirt (first layer), (2) the layer between the undershirt and the T-shirt (second layer), (3) the layer between the T-shirt and the outerwear (third layer), and (4) the surface of the outerwear (fourth layer).
We also measured the sensation of comfort, the skin temperature, the oral temperature and the degree of sweating of the subjects.
The experiments were conducted in a climatic chamber under conditions of 20.7±0.4°C, 61.2±3.6% RH and 2.5±0.5cm/sec.
The results we obtained were as follows:
1) While the subjects kept still, little change of humidity was observed with time in all the four layers. When the subjects were in motion, humidity increased as they started sweating. After the exercise ended, the humidity reached its maximum and then gradually decreased.
2) When subjects kept still, there was no difference in humidity in all the four layers of the outerwear. After the subjects began sweating with exercise, humidity rose in the first layer, followed in order by the second, the third, and the fourth layers. The humidity difference between the third layer (inside the clothing) and the fourth layer (the surface of the clothing) was greatest with outerwear V and was least with outerwear N.
3) During rest, exercise, and recovery, the humidity interrelationships of the first, the second, and the third layer were: outerwear V>outerwear G>outerwear N. The humidity interrelationship of the fourth layer was: outerwear N>outerwear G>outerwear V.
4) Before exercise, there were no changes in the temperatures of any of the four layers, regardless of the type of outerwear. After exercise took place, in the first and the second layers, the temperature remained unchanged for the first 7 to 8 minutes and then gradually went up. In the third and the fourth layers, the temperature went down once and then gradually went up. After subjects stopped moving, the temperatures of the four layers reached their peaks and then showed a gradual decrease.
5) During rest, exercise, and recovery, the skin temperature and the first layer temperature were the same. Temperature decreases were first observed in the first layer, then followed by the second, the third, and the fourth layers.
6) Before the motion started, there was no difference in the temperature of each layer of the three pieces of outerwear. The individual layer temperature of outerwear V was the highest at the maximum temperature point and at the temperature point 45 minutes after the motion stopped. The temperatures of outerwear N and outerwear G showed no significant differences.
7) The changes in the comfort sensation, the thermal sensation and the humidity sensation almost agreed with the temperature and the humidity changes inside clothing.
8) The permeability of outerwear materials turned out to have a considerable influence on the degree of sweating, the temperature and the humidity conditions inside clothing.

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Twenty-four rats were equally divided into 4 groups and maintained for 1 week as follows: Group A (normal control) with a synthetic normal diet and distilled water, group B with conventional total parenteral nutrition (TPN), i.e., TPN without essential trace elements (ETE), group C with TPN supplemented with a usual dose of ETE solution (TE-5), and group D with TPN supplemented with 3 times the usual dose of TE-5. Body weight, trace element concentrations in various tissues and certain blood biochemical parameters were determined in these rats. The results were as follows:
1) No significant differences in body weight were observed among the groups.
2) The iron concentrations in plasma and tibia decreased significantly in group B as compared with group A. The addition of TE-5 prevented these decreases, but dose-dependent increases in the concentrations of iron were observed in liver, spleen and kidney (groups C and D).
3) The zinc concentrations in plasma, whole blood, brain, heart, kidney and tibia decreased significantly in group B as compared with group A. The addition of TE-5 prevented these decreases dose-dependently (groups C and D).
4) The copper concentrations in plasma, whole blood, liver, spleen, kidney, testis and tibia decreased significantly in group B as compared with group A. The addition of TE-5 resulted in a tendency for these decreases to diminish (groups C and D).
5) The manganese concentrations of whole blood in group B decreased significantly as compared with group A. The addition of TE-5 caused the manganese concentrations of various tissues in groups C and D to increase significantly as compared with group A.
6) Alkaline phosphatase activity decreased in group B as compared with group A. The addition of TE-5 brought about a tendency for this decrease to diminish (groups C and D).
These results suggested that conventional TPN, i.e., ETE-free TPN, affected the concentrations of trace elements in various tissues of rats, and it is suggested that the supply of ETE is favorable during TPN.

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In order to study the influence of selenium (Se) on human health, the relationships between Se concentrations in whole blood and human body functions were studied in 331 healthy subjects living in Nagano Prefecture. The subjects with low concentrations of Se had lower values for hemoglobin, hematocrit, red blood corpuscles, and for the function of pulmonary ventilation, as well as lower concentrations of glucose and albumin. A lowered concentration of Se may result in anemia, even though a deficiency of iron cannot be observed. On the other hand, the subjects with high concentrations of Se had higher concentrations of uric acid, glucose and total cholesterol, higher values for diastolic blood pressure and the thickness of fat under skin, as well as a higher index of liver function. Moreover, these subjects had a good index of physical constitution and strength, and presented a large total consumption energy value. These results may show that in man, high Se concentrations in whole blood, indicate higher element concentrations in serum and better indexes of physical constitution and strength.

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In an attempt to carry out a pharmacokinetic study of the organophosphorous insecticide leptophos, which is known to produce delayed neurotoxicity (DNT), a practical method for the analysis of leptophos in tissue samples has been developed by utilizing high-performance liquid chromatography. Using this method, the pharmacokinetics of intravenously administered leptophos in hens were investigated. The following results were obtained:
1. The proposed method was suitable for the analysis of leptophos in biological tissues. The detection limit was 0.5ng and the recovery rate was over 90%.
2. The disappearance rate of leptophos in hens after administration was 70% at 6 hours and 93% at 96 hours. The half-lives calculated bi-exponentially were 1.37 hours for the early phase and 45.53 hours for the late phase. Since the leptophos detected in excreta was only 0.1% of the administered dose, its disappearance from the hen's body was due to its metabolization in the hen's tissue.
3. The half-lives of leptophos in blood calculated bi-exponentially were 0.50 and 7.57 hours.
4. The decline patterns of leptophos in tissue were considerably different from each other. While leptophos concentrations in adipose tissue and sciatic nerves decreased mono-exponentially, leptophos in other tissues (liver, kidney. heart muscle, leg muscle, brain and spinal cord) decreased bi-exponentially. The distribution of leptophos from blood to tissue seemed to be very rapid; however, redistribution from tissue to blood was extremely limited.
5. The long half-life of leptophos in sciatic nerves was especially noteworthy considering the manifestation of DNT.
6. The short half-life of leptophos in liver indicated the predominant role of liver in leptophos metabolism.
7. The results of this study do not coincide with the hypothesis that the metabolism of leptophos in species susceptible to DNT such as hens is slower than in non-susceptible species such as rats and mice. That is, in spite of the fact that this study was carried out under experimental conditions in which nerve damage would normally be manifestated, leptophos was metabolized rapidly.

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