On 945 female workers living in a dormitory of a woolen mill, which is employing 1, 300 workers approximately and equipped with about 30, 000 spindles as a production facility, the author took statistics of morbidity, and selecting frequent patients, the author collected statistics of the kind of their illnesses and computed the costs of related loss. In comparison to other famale employees, the author tried to determine and orientation of frequent patients in the workshop. (1) As to the frequency of getting ill in a year for 945 female workers living in a dormitory, those who experienced 11 times and over one year were selected as frequent patients. (2) As for the order of the frequency in the kind of illness there are scarcely any difference between frequent patients and other female employees. But as regards the frequency itself, frequent patients show about 7 times as many "diseases of bone and locomotor apparatus" followed by "diseases of nervous system and sensory organs", "those of respiratory" and "digestive organs" in order of frequency. And in any other diseases the frequency is higher in frequent patients. (3) As to the costs of loss related to illnesses, the cost per case does not show any great difference between frequent patients and other female employees. As to the expenses for medical treatment alone, however, the former indicates higher cost of loss than the latter. As to the cost of loss per person in a year, the former shows 36, 770 yen, while the latter 15, 957 yen; this means that the former incurrs the loss by about 2.3 times as much cost to the company.

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Eight healthy male operators of wharf cranes were chosen for fatigue condition investigation. The investigations were done once in summer and once in winter of which a report is presented herewith. The period of the investigation in winter was consecutive five days from February 9 and that in Summer was five days as well from July 19 on. Their working time was extended from 8 a.m. to 4 p.m. with one hour's rest period coming after every hour of actual labor. 1. The environmental conditions of the operating seat were examined at 10 a.m. and 2 p.m. every day and were found to be almost equal to outdoor conditions, The temperature in winter was 7.2°C at 10 a.m. and 10.2°C at 2 p.m., and in summer it was 24°C at 10 a.m. and 28°C at 2 p.m. The humidity was 48.5% at 10 a.m. and 45.7% at 2 p.m., in winter, and in summer 58.2% at 10 a.m. and 60.4% at 2 p.m.. 2. The investigation of their living schedules revealed that they actually worked daily 200 minutes in summer and 250 minutes in winter and that they slept daily 521 minutes in winter and 424 minutes in summer, that is, they were sleeping longer time in winter than in summer while working about equal length of time in both seasons. Besides, hours of excercise, recreational activities and miscellaneous work were longer in summer than in winter Their caloric consumptions, were about that of the medium labor. Their nutritional intakes were just about covering their needs but for calcium, vitamins A and C, which were all a little short. 3. Their blinker values and grip strength values were lower in summer than in winter, indicating that those physiological functions were decreased in summer. 4. In summer, blinker and flicker values as well as grip strength values tended to lower during the lapse of days, suggesting that their fatigue was accumulative. 5. All the three values occasionally became a littel higher immediately after the beginning of work in the moring, but lapse of working hours they Iowered gradually, and at the time the work was over they were so low indicating an onset of established fatigue. The fact that the decrease of flicker values more than that of grip strength or blinker values suggested that the mental fatigue was more marked than the muscular fatigue. This decrease of flicker values were more in summer than in winter, suggesting that fatigue was more masked in summer than in winter. 6. In the thourly alternate repetition of work and rest, it was observed that blinker and flicker values lowered by work and recovered to some extent by rest, but in the afternoon, the decline of these values increased while the recovery became less and less, flicker values recoveringnil by rest in some occasions. The same tendency was observed in grip strength values though not as distinct as in the cases of the other two.

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Report II. Discussion on Microdetermination Methods of PCP Pentachlorophenol (PCP) is oxidized through nitric acid treatment to chhloranil, which is colorimetrically determimined. Up to the present time, this PCP analytical method has been used in experimental studies on PCP. But this method is not safisfactory as regards sensitivity or accuracy, and more over, complicated and demands long operation time, so that we have not been able to determine PCP concentrations of the environmental air in industry by this method. Methylene blue method, which is an improved Hatkins's method by the author, and o-tolidine method deviced by author were compared each other. In point of sensitibity and accuracy, o-tolidine method is a little better than the methylene blue method, but the latter is far more concise. In conclusion it is said that the methylene blue method is better than the other in respect of industrial hygienic studies. Report III. Environment of a PCP Granulation Factory The author studied the environmental conditions of a pentachlorophenol (PCP) granulation factory, and discussed of improvement methods. About seventy employees are working in this factory, they are producing 10∼12 tons of products per day, and so this factory belongs to small or middle scale factories, but is has some environmental control equipments. Total output of the electric ventilating fans is 38.5 〓, and scrubbers consume 50∼60m³ of water per hour. PCP concentrations of factory's environmental air were mainly less than the probable safe concentration limit 0.5mg/m³ (Amer. Conference of Gov. Ind. Hyg. 1947). In samples of the air at a distance of about 100 meters from the factory, PCP concentrations of about 0.01mg/m³ were detected. Exhausted water from scrubbers contain PCP of 3.5∼5.0 ppm, which may deteriorate the quality of water of the river and sea. PCP concentrations of LD 50 for 48 hours of fresh water fish was 0.3∼0.6 ppm. Methods of treatment of PCP in water is studied, and it was discovered that active carbon adsorbs some of PCP, though this method is too expensive. Free PCP dissolves only abut 12 ppm in acidic water, so the circulation-precipitation-filtration system may be the most adeguate method.

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