Maximal forced expiration of 326 adult males 30 to 55 yr of age was measured four times during a follow-up of 4 yr. Acceptable results were obtained in 270 subjects three times or more. Forced vital capacity (FVC), forced expiratory volume in one second, maximal expiratory flows at 50% and 25% FVC divided by squared height (CFVC, CFEV₁, CV_max50, and CV_max25, respectively) were analyzed. Between- and within-subject variance were estimated by a linear model, including the effects of individual and age as explanatory variables. The goodness of fit of the model was satisfactory, since the coefficients of determination of the model were more than 0.96 for CFVC and CFEV₁ and around 0.91 for CV_max50 and CV_max25.
Estimated between-subject variance was far larger than within-subject variance, being more than ten times for CFVC and CFEV₁, about eight times for CV_max50, and five times for CV_max25. At the same time, annual decline of pulmonary function determined cross-sectionally was significantly larger than that determined longitudinally. These results indicated the superiority of longitudinal analysis to cross-sectional analysis in evaluating relatively small effects on pulmonary function especially in the case of chronic exposure of toxic substances in low doses.

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The relationship between cerebro-cardiovascular events (CCE) and work-related factors was examined in a cohort of 899 treated hypertensive men who were aged 50-59 yr and working more than 7 portal to portal hours (PPH). During the follow-up of 2.8 yr (2, 513 person-years), 27 cases of CCEs occurred, which were classified into 18 cases of stroke, 7 cases of acute myocardial infarction, and 2 cases of others. Using univariate analysis, it was found that managerial position and long PPH (more than 11 h) were significantly related to CCE (relative risk of 3.0 and 2.2, respectively) as well as risk factors such as emaciation, left ventricular hypertrophy, excessive sleeping hours, obesity, cigarette smoking, and inadequate control of systolic blood pressure. Using Cox proportional hazards general model, both managerial position and long PPH remained independently related to the risk of CCE (hazards ratio and 95% confidence interval, 4.1; 1.7-10.0 and 2.7; 1.1-6.2, respectively), after adjustment for other risk factors. These findings suggested that work-related factors, such as managerial position and long PPH, are independent risk factors of CCE among treated hypertensive male workers in the fifth decade.

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Aerobic dance has recently become popular in all age groups, but the injuries among full-time and part-time aerobic dance instructors have rarely been pointed out in Japan. In this study the subjective symptoms of 63 female instructors in Gifu area were evaluated through health questionnaire. As a control group, 94 female students of the same age group were also included to compare the prevalence of subjective symptoms. Multiple logistic regression analysis was applied to observe the relation between instructors' symptoms and working conditions. The following results were obtained:
1) Complaints of leg and foot pain and laryngeal discomfort were significantly greater in instructors than in students even after adjusting for age and participation in other sports.
2) A significant positive relation was found in instructors between the frequency of dance lessons (times/wk) and various symptoms (calf pain, foot pain, sore throat, and hoarse voice) after adjusting for age and participation in other sports.
These results suggest that leg and foot pain and laryngeal discomfort are characteristic symptoms of aerobic dance instructors. Consideration should be made to adjust the frequency of dance lessons in order to reduce these symptoms.

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A simple method for measuring cleaning solvent in air by gas detector tube for ethyl acetate was evaluated with regard to basic performance such as sensitivity, precision, discolor tone and effect of temperature. Satisfactory results were obtained with regard to sensitivity, precision, discolor tone in the indicator and stability of discolored length. Range of measurable concentration by the present method was about 25-800 mg/m³. It was found necessary in the present method to make temperature correction. It was concluded from these results that the present method is useful for measuring cleaning solvent in air. However, positive effect on discolored length was found by vapor of toluene and ethyl acetate when they coexisted. No effect on discolored length was found by vapor of acetone, methanol or trichloroethylene.

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FEP and other hematological parameters were measured in 157 healthy rural residents (98 females and 59 males). The mean FEP in females was higher than in males (p<0.05); mean±SD=62.98±19.36 and 54.57±21.20 μg/dl·pcv, respectively, although both of the means were within normal limits. There was no significant sex difference in erythrocyte ALA-D activity. Whole blood lead (Pb-B) level in females showed a tendency to be lower than in males, but there was no significant sex difference in erythrocyte lead level. The mean value of hematocrit (Ht), hemoglobin (Hb) and iron in serum (Fe-S) were lower in females than in males (p<0.01). Serum GOT and GPT level tended to be lower in females than in males (0.05<p<0.1).
There was hardly any significant relationship between Pb-B and each parameter of lead exposure, because the subjects in this study were only rural residents with no occupational lead exposure and with their Pb-B levels being extremely low. As for the parameters of anemia, Fe-S was positively correlated with Ht and Hb level and negatively correlated with FEP level. By sex, Fe-S was correlated with Ht and FEP level only in females.
As for the possible reasons why FEP level in females is higher than in male, women tended to have iron-deficiency induced by blood loss due to menstration, pregnancy, and difference in dietary pattern from males.

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An experimental study on Donryu rats was primarily carried out to elucidate sex difference in FEP level. Each of 33 male and 33 female rats was divided into 3 groups; that is, control group (5% glucose solution only), low lead dose group (Pb 0.5 mg/kg·BW) and high lead dose group (Pb 5mg/kg·BW). Lead was injected intraperitoneally once a week for 6 wk. FEP, Ht, urinary coproporphyrin (CP-U), δ-aminolevulinic acid (ALA-U) and porphobilinogen (PBG-U) were determined once every two weeks for 6 wk, and whole blood lead (Pb-B) at the end of the experiment.
Mean value of Ht was lower in females than in males throughout the period of the experiment in almost all groups. Pb-B level of all groups and erythrocyte Pb level of high dose group were higher in males than in females.
FEP level without lead injection and with low lead exposure was higher in males than in females. By analysis of variance for gain from initial FEP level, only the low lead dose group demonstrated a significant sex difference (p<0.01); the female group tended to increase, while the male group maintained a constant level. Furthermore, FEP/Pb-B ratio in females was higher than in males only for the high dose group. The changes in ALA-U in male and female rats were comparable to those in FEP. Unlike FEP and ALA-U, CP-U level was higher in males than in females only for the high lead dose group.
In this study using rats, sex difference in FEP level was different from that in human. At the present stage, the cause of this difference could not be determined. The effect of sex hormones in rats should be elucidated.

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[in Japanese]

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