An attempt was made to classify persons with simple obesity from the viewpoint of health education. Subjects of the study were 1, 278 male workers in a financing company who underwent health examination. At the time of health examinations, questionnaire survey concerning their life styles was carried out on all the subjects. The obese group consisted of 127 subjects whose obesity indices were over 15% and the control group consisted of 342 subjects whose obesity indices ranged from -5 to 5%. Subjects in the obese group were classified into four clusters based on cluster analysis using five life-style parameters; that is, frequency of taking breakfast, frequency of taking staple food, drinking habits, smoking habits, and frequency of exercise. The first cluster (N=10) included inactive persons, the second cluster (N=46) non smokers, the third cluster (N=39) smokers and heavy drinkers, and the fourth cluster (N=32) smokers and non-drinkers. Comparison of the four clusters of obese persons with the control group revealed the following findings:
1) All the four clusters had significantly high frequencies of abnormal values of triglyceride (TG) and fasting blood sugar (FBS).
2) The first cluster had significantly high frequencies of abnormal values of glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT).
3) The second cluster had significantly high frequencies of abnormal values of systolic and diastolic blood pressure, total cholesterol, TG, FBS, uric acid, GOT, GPT and gamma glutamyl transferase (GGT).
4) The third cluster had significantly high frequencies of abnormal values of diastolic blood pressure, TC, GPT and GGT.
5) The fourth cluster had significantly high frequencies of abnormal values of high-density lipoprotein cholesterol.
These clusters of obese persons based on their life styles showed different patterns in the prevalence of abnormal values of some medical indicators. The results of the present study suggest that this type of classification of obese persons is useful for conducting effective health education for obese individuals.

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Occupational exposures to potentially hazardous substances may vary considerably because of factors such as sampling and analytical errors, and intraday and interday environmental fluctuations in contaminant concentration. Of these factors, day-to-day environmental fluctuations most likely affect daily exposure averages over days, weeks, months or years.
A new method based on day-to-day fluctuations of daily exposure averages (geometric standard deviation) was developed for making reliable assessment of the employee's exposure situation. It is assumed that daily exposure averages of a worker are lognormally and independently distributed statistically. Finally, a classification scheme on the basis of n days measurements is presented. 95% upper limit or arithmetic mean of individual exposure averages (8-h TWAs) can be evaluated in comparison with an established standard. The method may provide an approximate estimate because of statistical premise, but it can be utilized for practical purposes, particularly, in case where only one or two days are being monitored.
An action level concept based on random sampling and analytical errors and interday variations developed by OSHA/NIOSH, and a sampling and decision scheme based on one-sided tolerance limits proposed by Tuggle (1982) are also discussed.

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An assessment of the employee's exposures to industrial hazardous substances using the proposed method described earlier was conducted on 49 workers exposed to lead.
As it is assumed that the daily exposure averages are lognormally distributed, geometric standard deviation (σ_g) representing true interday fluctuations of the daily exposures was estimated by personal exposure measurements of every worker for two consecutive days. The estimates (S_g) ranged from 1.00 to 5.35 with a median of 1.4 and a 90% upper limit of 2.4.
According to a classification scheme in the proposed method, exposure levels (I to III) were calculated using σ_g of 1.4 and 2.4. An exposure class based on a single day measurement was evaluated and compared to that based on measurements for two consecutive days. As a result, the decision of the exposure levels and classes from only one day monitoring could be made by using both σ_g of 1.4 and 2.4, representing ordinary and high interday fluctuations, respectively.
More accurate estimate of geometric standard deviation of interday fluctuations by exposure monitorings would provide a more reliable assessment of the worker's long-term exposure situation.

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The variations of sublingual temperature, pulse rate, flicker fusion frequency (CFF), subjective fatigue feelings (SFF) and 8 selected reaction times and the relationships between them were examined in six university students under the condition of successive 6-h delayed shift with 8 sleeping h and 22 waking h for 6 d. SFF was measured by the scales proposed by the Japanese Society for Industrial Fatigue Research. On the 2nd d when the shifting was started after the subjects had slept from 00:00 to 08:00 and on the 3rd d after sleeping h of 06:00 to 14:00, the variations of sublingual temperature, pulse rate and CFF showed a pattern of circadian rhythm. However, on the 4th-5th d the rhythms of sublingual temperature and pulse rate were flattened. On the other hand, CFF demonstrated a variation of having a nearly constant tendency till 08:00, followed by a gradual decrease during the daytime. The variation of SFF (the scale of “sleepiness and dullness”) was similar to that of CFF, although the change of the score was in the opposite direction. On the 3rd-4th d, the 4th-5th d and the 6th d, significantly high rank correlations were observed between sublingual temperature and pulse rate and between CFF and SFF. However, between sublingual temperature and CFF, a high correlation which was observed on the 1st and the 2nd d was not seen on the 4th-5th and 6th d. Eight selected reaction times were shortened during the experimental days, but there was no consistent pattern of variation within these days. The results of the experiment showed that the relationship between CFF and SFF exists during the daytime when the arousal level is low.

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