Toluene has been used widely as organic industrial solvent separately or together with other solvents. Many workers contact toluene resulting in acute and chronic poisonings. Problems studied include its acute and chronic epidemiology, toxicity on animals and human beings, does-response relationships, fate in the living body (absorption, distribution, metabolism and excretion), maximum allowable concentration and biological monitoring limit value of this chemical. In this paper many recent reports of toxicity and metabolism of toluene are reviewed.

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A comparative study of the cold water immersion tests at 5°C and 10°C for 10 min was carried out to know either test is excellent for diagnosis of the vibration disease. Skin temperatures, vibratory sense thresholds, recovery times of blood flow by the nail press test and pain sense thresholds of 36 chain saw and bush cutter operators with the vibration disease were measured before, immediately, 5th min and 10th min after the cold water immersion test. Furthermore, skin temperatures were measured from 6th to 10th min from the begining of the immersion at 1 min interval. The results obtained are as follows: Skin temperatures in the cold water immersion test at 5°C showed a faster recovery pattern than those of the immersion test at 10°C, and skin temperatures after the cold water immersion tests at 5°C and 10°C crossed over within 5 min after the immersion. The cross pattern of the skin temperature was not significant in the chain saw group, but it was significant in the bush cutter group. Vibratory senses lowered after the cold water immersion and the values of the vibratory sense threshold affected by the immersion at 10°C were more than those by the immersion at 5°C in both chain saw and bush cutter operators with the vibration disease. Recovery time of the blood flow by the nail press test was prolonged by the cold water immersion, but no difference between 5°C and 10°C immersion tests was recognized. Pain sense became dull by the cold water immersion, but the difference of pain sense affected by the cold water immersion tests between at 5°C and 10°C was not recognized. Above results of the skin temperature, the vibratory sense, the nail press test and the pain sense affected by the cold water immersion test at 5°C and 10°C for 10 min indicate the difficulty to judge whether either immersion test at 5°C or 10°C is better than other tests for diagnosis of the vibration disease because no remarkable difference between the two immersion tests was found. However, the group of vibration disease among both chain saw and bush cutter operators showed remarkably different values in comparison with normal healthy subjects in each measurement of items for special health examinations of the vibration disease. It may seem that it is preferable to adopt the cold water immersion test at 10°C which gives less pain by immersion.

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For a simple analysis of organic solvent vapours in working environmental air, we investigated the following method. First, join the adsorption tube (2 ml of 60-80 mesh silica gel packed in a 5 mmφ×18 cm glass tube) to hand vacuum pump and suck 200 ml of the sample air. After adsorption, join this adsorption tube to the sampling bottle under reduced pressure. Second, open the cock of the sampling bottle and heat only the adsorption tube in an oven for 3 min. In the operation mentioned above, organic solvent vapours desorbed from the silica gel transfer smoothly into the sampling bottle. After desorption, take 1 ml of air from the sampling bottle and determine the sample quantities with the gas chromatograph. Sample solvents used were as follows: n-hexane, cyclohexane, benzene, toluene, m-xylene, styrene, 1.1.1-trichloroethane, dichloromethane, tetrachloroethylene, ethylacetate, acetone, methylethylketone, methylisobutylketone, methanol, ethanol, n-propanol, and n-butanol. We obtained the following results. (1) 60-80 mesh silica gel is appropriate for this method. (2) Heating temperature to get 100% recovery varies with the type of organic solvent. m-Xylene and styrene require 250°C, methylisobutylketone and n-butanol 200°C, and the others 150°C. (3) If the adsorption tube is preserved in a freezer at -20°C, no decrease is observed for up to 7 days. At room temperatures, however, 1.1.1-trichloroethane, dichloromethane, tetrachloroethylene, n-hexane, and cyclohexane decrease by the amount 4-10% in the tube for each 24-hour period. These sample should be preserved at lower temperatures soon after adsorbing on the silica gel. This method is simple and accurate, so valid for analysis of organic solvent vapours in the working environmental air.

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We investigated vibration hazards of chipping-hammer operators at the time when no preventive measures were taken against them. Their working hours were 420 minutes in a day, and 180-210 minutes on an average were spent in using chipping-hammers. The vibration exposure time was 50-80 percent of the total chipping hours. The outdoor temperature in the daytime was -2-2°C in winter and 19-25°C in summer. The indoor temperature of the workshop was thought to be similar to that of the outdoor because of the wind that blew through. Chipping-hammers were mainly CH-11 type and partially N-3, made by Hiroshima Kogyo Co. Ltd. Both of the tools weighed 4-5 kg, the noise level was 114-115 phon (C), and the vibration energy at the handle 143-147 dB, ref. 100 dB=1 m/sec² (rms). In this iron foundry many chipping-hammers have been introduced since 1955, but no preventive measures have been taken against vibration hazards. Physical examinations were made on 40 workers in March, 1975. Twenty-five men among them were using chipping-hammers (Group A), 7 had stopped using them for less than two years because of the severe vibration disease (Group B), and 8 were healthy physical workers who had not used these hammers and any other vibrating tools (Group C). Their average age and the term of usage of chipping-hammers respectively (in years) were, Group A: 45.1, 11.7, Group B: 44.3, 11.1, Group C: 42.8. Attack rate of waxy white fingers was 64% in Group A, 43% in Group B, 0% in Group C. The term of the first appearance of the attack was as follows; Group A:40% within 5 years, 56% within 10 years. The attack of benumbed hands and fingers was 60% in Group A, 29% in Group B, 0% in Group C. And the term of the first appearance of the numbness was as follows; Group A: 36% within 5 years, 52% within 10 years. The subjects were given such objective tests as decrease in the grasping power and pinching power, tapping test, and cooling test by immersing the hands in cold water at 10°C. Group A was worst in the results of physical examinations and Groups B and C were of good results in ascending order. Abnormalities discovered through the objective examinations proved to correlate with subjective complaints. Therefore, it can be said that these tests are useful in picking up suffering men among laborers using chipping-hammers. Because of the absence of the preventive measures against the vibration disease for the past many years, the incidence of the vibration disease has been large enough. The preventive measures should be taken immediately.

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For the purpose of clarifying the effect of night and shift work on daily lives of workers, hours for daily activities and sleeping hours of guardmen were investigated during a week and a month, respectively. The subjects included 36 alternate-day shift workers, aged 37.0±12.4 years on the average, 6 permanent night duty workers, aged 53.8±3.7 years, and 6 normal duty workers, aged 41.8±10.5years. The characteristics of each duty have been described in the previous report. The results were as follows: (1) The investigation of daily life hours during a week showed that the daily working hours including commuting hours averaged 831 min, 970 min, and 568 min, for the alternate-day shift workers, for the permanent night duty workers, and for the normal duty workers, respectively. Therefore the former two were longer than the last, showing about 60% of the daily life hours. In contrast, their sleeping and socio-cultural hours were shortened, and these hours were revealed to be more shortened by longer working hours. (2) The frequency of sleeping times in one-month was 40 and 59, for the alternate-day shift workers and for the permanent night workers, both being significantly greater than 31 for the normal duty workers. The frequency of sleeping times at home was 16 for the alternate-day shift workers, while only 4 for the permanent workers. These results indicate both shift workers had very few chances to have a good sleep at home. (3) The average sleeping hours for a month was 6.9 hr in a day for the alternate-day shift workers and 7.0 hr for the permanent night workers, while 8.1 hr for the normal duty workers. This result indicates that the shift workers were obliged to have insufficient sleep for a month, compared with the normal duty workers. The insufficient sleep were suggested to be caused by such factors as consecutive night duties, short interval between duties, long spell of portal-to-portal hours and high freguency of night works. (4) It was observed that extremely insufficient sleep of the shift workers, which was brought about by successive duties, may be compensated, although a little, by full night sleep before and after the duties as well as by taking a good diurnal sleep. There were also shown clear individual differences with regard to how to compensate the sleep loss. It was concluded from these results that countermeasures such as shortening of total and overtime working hours, decrease in frequency of night duties as well as increase in frequency of off-duty days should be urgently taken, in order to make sure of guardmen's full sleep and to improve their health, from the viewpoint of industrial hygiene.

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Subjects were exposed in a climatic chamber for 60 min to air temperatures at -5°C, -20°C and -30°C wearing cold-protective clothings. The following manual functions were studied as a function of air temperatures, upper limb skin temperatures, mean skin temperatures or mean body temperatures: handgrip strength, pinch strength, bolt-removing task and counting task. The decline of skin temperatures was observed during cold exposure, wearing cold-protective clothing. At 60 min of cold exposure to air temperatures at -5°C, -20°C and -30°C, mean skin temperatures were 30.2°C, 27.8°C and 26.5°C respectively, then II-right-finger skin temperatures were 20.7°C, 13.1°C and 11.8°C respectively. There were reductions only on limited number of manual functions as compared with functions under normal conditions, that is, bolt-removing task and handgrip strength did not significantly change during cold exposure, whereas pinch strength and counting task decreased with lower surface temperatures and body temperatures. Body or surface cooling resulted in reductions in pinch strength by the order of 50%. The rising of the body storage index, which was calculated from the change of the mean body temperature, resulted in a linear decrease in counting task. The capacity to perform manual handling task and muscle strength appeared to vary according to the muscle used for these performance and depending on the levels of cold stress. Body cooling, combined with local upper limb cooling, produced the largest performance decrements.

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