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Abstract: There are many reports of reduction of zinc level and rise of copper level in serum of patients with liver disease. However, there are a few reports that compare the trace elements in tumor tissues and nontumor tissues of the liver with hepatoma. We studied trace element distribution in tumor tissues and nontumor tissues of liver with hepatoma and compared them with data from normal liver tissues. Zinc (Zn), copper (Cu), selenium (Se), cadmium (Cd), mercury (Hg), and iron (Fe) were chosen as the trace elements to be observed. We observed falls of Zn, Cd, and Hg levels in tumor tissues and the rise of Cu level as a result of this investigation. Zn, Cd, and Hg levels in tumor tissues were significantly lower than those in nontumor tissues and Zn, Cd, and Hg levels in nontumor tissues were significantly lower than in normal liver tissues. This tendency was clearer for Cd and Hg than for Zn. Although the distribution of Cu was not significant, a distribution contrary to that of Zn was shown. These findings indicate that the distribution of Zn, Cd, and Hg can serve as supportive evidence that could be useful as a tumor marker. Selenium showed almost the same accumulation tendency among tumor tissues, nontumor tissues, and normal livers. Although correlation was observed among most metals in the normal liver, there was almost no correlation in tumor tissues.

Specialist Qualification Program for Physicians Prepared by the Japan Society for Occupational Health: Toshiteru Okubo. University of Occupational and Environmental Health—The Japan Society for Occupational Health introduced a new qualification program for occupational physicians in 1992. Qualification is based on an examination and in this examination candidates must undergo the following five different types of evaluations. 1. Written tests 2. Oral examinations 3. Group discussions 4. Presentation 5. Personal interview. Two types of written tests are given to evaluate the knowledge level of the candidates, a short answer test and an essay. The oral examination is given to a group of 4 to 6 candidates. Two examiners are assigned to each group and 10 questions are asked of the candidates in turn. To the same group but with the different examiners assigned, more complicated problems are given in the discussion section. Each candidate is randomly given a subject for personal presentation from a pool of subjects. Three examiners are assigned to each candidate in the personal interview. Sixty percent is the criterion for success. For each of the evaluations other than the written tests, three evaluation categories, namely knowledge, expertise and personal attitude are introduced. Based on these checking points the examiners are requested to give a comprehensive evaluation of each candidate by points with one hundred as the perfect score. If the final evaluation in all three categories is successful, the candidate has passed the examination. Evaluation of this examination has been carried out concerning variation according to examiner, relationship between examination types and impression given by the candidates.

Specialist Qualification Program for Physicians Prepared by the Japan Society for Occupational Health: Toshiteru Okubo. University of Occupational and Environmental Health—The Japan Society for Occupational Health introduced a new qualification program for occupational physicians in 1992. Qualification is based on an examination and in this examination candidates must undergo the following five different types of evaluations. 1. Written tests 2. Oral examinations 3. Group discussions 4. Presentation 5. Personal interview. Two types of written tests are given to evaluate the knowledge level of the candidates, a short answer test and an essay. The oral examination is given to a group of 4 to 6 candidates. Two examiners are assigned to each group and 10 questions are asked of the candidates in turn. To the same group but with the different examiners assigned, more complicated problems are given in the discussion section. Each candidate is randomly given a subject for personal presentation from a pool of subjects. Three examiners are assigned to each candidate in the personal interview. Sixty percent is the criterion for success. For each of the evaluations other than the written tests, three evaluation categories, namely knowledge, expertise and personal attitude are introduced. Based on these checking points the examiners are requested to give a comprehensive evaluation of each candidate by points with one hundred as the perfect score. If the final evaluation in all three categories is successful, the candidate has passed the examination. Evaluation of this examination has been carried out concerning variation according to examiner, relationship between examination types and impression given by the candidates.

The Effects of a Health Promotion Program on Body Mass Index: Katsuya Furuki, et al. Department of Occupational Health, Kyoto Industrial Health Association—The objectives of the study were to clarify the effects of a health promotion program approved by the “Total Health Promotion Plan (THP)” sponsored by the Japanese Ministry of Labour on body mass index (BMI) and to identify the potential value of BMI. A group of 392 men and 115 women aged 26‐55 years who had taken part in THP for four years were the subjects of this follow‐up study. Longitudinal change in BMI and other medical parameters (including systolic and diastolic blood pressure, total cholesterol and HDL‐cholesterol) were analyzed in the THP group in comparison with those of a control group (matched by sex, age and term of follow‐up). No significant difference in medical parameters was detected between the THP group and the control group, but major findings indicate that change in BMI is closely related to change in other medical parameters and that lifestyle deterioration of overweight workers increases BMI and lifestyle improvement (especially dietary habits) reduces BMI. The present study suggests that lifestyle improvement results in a decrease in BMI followed by improvement in medical parameters. Both BMI and change in BMI appear to be comprehensive indicators of the health status of overweight workers.

Ecological Relationship between Mesothelioma Incidence/Mortality and Asbestos Consumption in Ten Western Countries and Japan: Ken Takahashi, et al. Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health—The objective of the present study was to evaluate the ecological relationship between mesothelioma incidence/mortality and per capita asbestos consumption in ten Western countries and Japan. The two national indices used to assess the geographical correlation were the most recent incidence/mortality rate of mesothelioma for the population over 15 years of age, and the per capita asbestos consumption rate of approximately 10‐25 years ago for the population of ail ages at that time. Among the ten Western countries, a clear linear relationship was shown between the mesothelioma incidence/mortality rate and the preceding per capita asbestos consumption rate with the Spearman correlation coefficient at 0.70 (p=0.03), and R2‐value at 66%. However, the data‐point for Japan was situated apart from the linear relationship due to the lower mesothelioma mortality rate, and when combined with other Western countries, the significant relationship diminished. It is possible that the asbestos consumption curve for Japan in past years lagged behind that for the Western countries and the cumulative exposure effect has not yet reached the level that can be expected from other Western countries.

Seasonal Variation in Sudden Death among Japanese Workers: Why are There Peaks in Spring and Winter?: Tsutomu Hoshuyama, et al. Department of Environmental Epidemiology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health—These days particular attention is being paid to sudden death among Japanese workers, an issue requiring an urgent solution. This study describes the seasonal variation in sudden death, and examines the synchronization of death with workers' busy period. Questionnaires were sent to occupational health physicians belonging to a representative sample of large‐scale working establishments in Japan. Inquired were cause, date, and other demographic information on sudden death cases that had occurred in each establishment from 1988 to 1992. The seasonal variation in sudden death was analyzed by age, cause of death, and industry, and synchronization of death with the period of settlement of accounts (SA) of the establishment was examined. Of 488 male sudden deaths reported, 362 were categorized as being of cardiovascular origin. Both the 488 cases and the 362 cardiac cases had two peaks of occurrence in March‐April and in Novennber‐December with statistical significance (p<0.01). Of the 201 cases aged 45‐54, 70 (35%) died within two months of the SA. The peak in March‐April may be accounted for by an increased number of sudden deaths among workers aged 45‐54, whereas the peak in November‐December may be accounted for by an increased number of sudden deaths among the entire worker population studied. Because both peaks were associated with busier periods for workers in Japan, work environmental factors may affect the seasonal variation resulting in such a distinctive shape of the curve for sudden death among workers.

Seasonal Variation in Sudden Death among Japanese Workers: Why are There Peaks in Spring and Winter?: Tsutomu Hoshuyama, et al. Department of Environmental Epidemiology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health—These days particular attention is being paid to sudden death among Japanese workers, an issue requiring an urgent solution. This study describes the seasonal variation in sudden death, and examines the synchronization of death with workers’ busy period. Questionnaires were sent to occupational health physicians belonging to a representative sample of large-scale working establishments in Japan. Inquired were cause, date, and other demographic information on sudden death cases that had occurred in each establishment from 1988 to 1992. The seasonal variation in sudden death was analyzed by age, cause of death, and industry, and synchronization of death with the period of settlement of accounts (SA) of the establishment was examined. Of 488 male sudden deaths reported, 362 were categorized as being of cardiovascular origin. Both the 488 cases and the 362 cardiac cases had two peaks of occurrence in March–April and in Novennber-December with statistical significance (p<0.01). Of the 201 cases aged 45–54, 70 (35%) died within two months of the SA. The peak in March–April may be accounted for by an increased number of sudden deaths among workers aged 45–54, whereas the peak in November–December may be accounted for by an increased number of sudden deaths among the entire worker population studied. Because both peaks were associated with busier periods for workers in Japan, work environmental factors may affect the seasonal variation resulting in such a distinctive shape of the curve for sudden death among workers.

The Effects of a Health Promotion Program on Body Mass Index: Katsuya Furuki, et al. Department of Occupational Health, Kyoto Industrial Health Association—The objectives of the study were to clarify the effects of a health promotion program approved by the “Total Health Promotion Plan (THP)” sponsored by the Japanese Ministry of Labour on body mass index (BMI) and to identify the potential value of BMI. A group of 392 men and 115 women aged 26-55 years who had taken part in THP for four years were the subjects of this follow-up study. Longitudinal change in BMI and other medical parameters (including systolic and diastolic blood pressure, total cholesterol and HDL-cholesterol) were analyzed in the THP group in comparison with those of a control group (matched by sex, age and term of follow-up). No significant difference in medical parameters was detected between the THP group and the control group, but major findings indicate that change in BMI is closely related to change in other medical parameters and that lifestyle deterioration of overweight workers increases BMI and lifestyle improvement (especially dietary habits) reduces BMI. The present study suggests that lifestyle improvement results in a decrease in BMI followed by improvement in medical parameters. Both BMI and change in BMI appear to be comprehensive indicators of the health status of overweight workers.

Ecological Relationship between Mesothelioma Incidence/Mortality and Asbestos Consumption in Ten Western Countries and Japan: Ken Takahashi, et al. Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health—The objective of the present study was to evaluate the ecological relationship between mesothelioma incidence/mortality and per capita asbestos consumption in ten Western countries and Japan. The two national indices used to assess the geographical correlation were the most recent incidence/mortality rate of mesothelioma for the population over 15 years of age, and the per capita asbestos consumption rate of approximately 10-25 years ago for the population of ail ages at that time. Among the ten Western countries, a clear linear relationship was shown between the mesothelioma incidence/mortality rate and the preceding per capita asbestos consumption rate with the Spearman correlation coefficient at 0.70 (p=0.03), and R2-value at 66%. However, the data-point for Japan was situated apart from the linear relationship due to the lower mesothelioma mortality rate, and when combined with other Western countries, the significant relationship diminished. It is possible that the asbestos consumption curve for Japan in past years lagged behind that for the Western countries and the cumulative exposure effect has not yet reached the level that can be expected from other Western countries.

This study examines the impact of factors indicating a poor prognosis on rehabilitation effectiveness of 124 first stroke patients admitted to a comprehensive rehabilitation unit in Kitakyushu, Japan. A multiple regression model, employing a forced entry of variables guided by prior studies on these factors, found four significant factors. Lack of motivation, urinary incontinence, each 10 years of age, and each day's delay from stroke onset to the commencement of rehabilitation reduced the rehabilitation effectiveness by 20%, 15%, 4%, and 0.1% respectively. The values of beta-coefficients showed that onset-rehabilitation delay and lack of motivation were relatively important in our model. These findings are consistent with clinical impressions and provide useful information for planning stroke rehabilitation programmes.

There are few reports on lead exposure in children living in the center and the suburbs of large cities. As subjects of epidemiological investigations on the effects of lead exposure in ambient air, school children are very significant in that they have a relatively limited sphere of movement in their daily life. In a previous study the authors compared school children living in the center of Tokyo and those in a suburb of the city and reported that the blood lead levels (PbB) were significantly higher in children living in urban areas [12]. However, it was concluded that further investigation of factors other than ambient air was required to determine the cause of this difference. In the present study, the method used was the same as that of the previous study. However, the areas investigated in the present study were distant from those of the previous study. The results again indicated that the average PbB of school children in the city-center was approximately 2.5–4.8 mg/100 g higher than that of suburban school children, a statistically significant difference. An analysis made on the combined data from both studies according to age revealed that urban school children indicated the highest level among younger urban children, showing a gradual decrease in lead levels as age increased (from 10 to 15 years of age). Suburban children did not show this decline. As a result, it was concluded that these differences in PbB might not be attributable only to lead exposure in ambient air, but to lead exposure from sources such as street dust to which young children are more readily exposed than adults.

Objective –To estimate the optimal cut off point in a new immunological method (OC-Hemodia®) for faecal occult blood testing (FOBT).Setting –A corporate colorectal cancer screening programme in Japan.Method –The screening programme targeted colorectal cancer and adenomatous polyps ≥ 10 mm, and was conducted on 27 860 participants (age ⩾ 40) during 1991–92. The follow up consisted of diagnostic management by total colonoscopy on positive screened subjects exceeding the manufacturer recommended cut off level of 50 ng/ml faecal haemoglobin, and the identification of false negative cases by health insurance claims. The optimal cut off point was estimated by the positive predictive value, receiver operating characteristic (ROC) curve, and a cost effectiveness analysis. In this study evaluation was carried out only for cancer as the target disease.Results –At the current cut off level of 50 ng/ml the sensitivity and specificity were 86.5% and 94.9%. When the optimal cut off point was estimated the highest positive predictive value was obtained at 250–350 ng/ml. The ROC curve showed that the sum of sensitivity and specificity is maximised at 50 ng/ml, but evaluation of the ratio, change in sensitivity/change in false positive rate, pointed to higher optimal cut off points, showing marked changes occurring at about 200 ng/ml. The average cost per case was lowest at 250–300 ng/ml. Overall, the optimal cut off point was estimated to be about 200 ng/ml, at which the sensitivity and specificity of the test would be 77.5% and 98.9%, respectively.Conclusion –The optimal cut off point of the new immunological method of FOBT was estimated to be about 200 ng/ml, a value which, more than the current cut off value, favours specificity over sensitivity.

Recent State and Future Scope of Occupational Health in Japan: Toshiteru Okubo. Occupational Health Training Center, University of Occupational and Environmental Health, Japan—The most significant characteristic of the working population of Japan is aging. The increase in the senior population puts substantial pressure on the health insurance and pension systems and many health insurance organizations have decided to cut down voluntary programs on occupational health. The nature of occupational diseases has changed from health impairments caused by a single prominent occupational factor to unspecific health problems caused by the combinedeffect of both occupational and non‐ occupational factors. Diseases occurring through this mechanism are called work‐related diseases, in contrast to typical occupational diseases. It is no longer effective to simply remove a single hazardous environmental factor, as has been the major approach in occupational health. A comprehensive approach is more important than ever. Health promotion in the work place is therefore one of the most important services in Japan. Along with the improvement of the work environment, workers’ values regarding labor have also changed and they seek working conditions better than the threshold level to prevent health hazards11). Under these conditions the basic concept of occupational health should not be limited to only minimizing the minus health effects, but it should introduce the idea of seeking positive health. Positive health always seeks to improve health from any level, but up to now medical science has paid very little attention to positive health and there is lack of knowledge and experience. The highest priority of research in this field is therefore to be found in the development of positive health indicators.

Recent State and Future Scope of Occupational Health in Japan: Toshiteru Okubo. Occupational Health Training Center, University of Occupational and Environmental Health, Japan—The most significant characteristic of the working population of Japan is aging. The increase in the senior population puts substantial pressure on the health insurance and pension systems and many health insurance organizations have decided to cut down voluntary programs on occupational health. The nature of occupational diseases has changed from health impairments caused by a single prominent occupational factor to unspecific health problems caused by the combinedeffect of both occupational and non- occupational factors. Diseases occurring through this mechanism are called work-related diseases, in contrast to typical occupational diseases. It is no longer effective to simply remove a single hazardous environmental factor, as has been the major approach in occupational health. A comprehensive approach is more important than ever. Health promotion in the work place is therefore one of the most important services in Japan. Along with the improvement of the work environment, workers’ values regarding labor have also changed and they seek working conditions better than the threshold level to prevent health hazards11). Under these conditions the basic concept of occupational health should not be limited to only minimizing the minus health effects, but it should introduce the idea of seeking positive health. Positive health always seeks to improve health from any level, but up to now medical science has paid very little attention to positive health and there is lack of knowledge and experience. The highest priority of research in this field is therefore to be found in the development of positive health indicators.

A cohort study on platers in Tokyo was carried out using the records of the Tokyo Health Insurance Society of Plating Industry. The type of work and chromium-exposure history of each member of this society was investigated by a questionnaire sent to the manager of each factory. The recovery rate of the questionnaire was 70.5%. Survival information on retired subjects was obtained from the offices of Japanese family registration system (“koseki”).

There are few reports on lead exposure of children in or near large cities which compare the blood lead values of those who live towards the center of cities and those living in the suburbs. Since lead poisoning among children in the United States is a serious problem, the authors wished to study the effects of lead in the environment on the young population in and near Tokyo. The results indicated much lower blood lead levels in school children than in adults in Tokyo. There is a statistically significant difference in PbB levels between urban and suburban children although the actual difference was only 1 – 2 µg/100 g. Thus children living in urban Tokyo seem to have slightly higher body burdens of lead than suburban children. This difference in lead body burden is most probably not attributable to lead in ambient air but to other factors such as food. However, the possibility of the contribution of lead in ambient air cannot be totally rejected. Further investigation is required to identify the factor or factors which are responsible for this phenomenon.