Toshio Toyama

Photochemical air pollution. Its effects on respiratory function of elementary school children.

The effects of photochemical air pollution on respiratory function of Tokyo elementary school children were investigated. Nine types of environmental factors were continuously recorded. Seven categories of respiratory function tests were performed on 20 normal 11-year-old children once a week from June to December 1972, as a general rule. The correlation coefficients between respiratory function measurements and each of the environmental factors were calculated. The maximum expiratory flow rate (V max) showed high correlation with the largest number of environmental factors. Among environmental factors, temperature highly affected various respiratory function tests. The O3 was significantly associated with airway resistance (Raw) or specific airway conductance (Gaw/Vtg), NO or NO2 with V max, and temperature with Raw, Gaw/Vtg, and V max. Two subjects among all subjects were considered as the reactors to the environmental factors.

Absenteeism of Shift and Day Workers with Special Reference to Peptic Ulcer

The causes and duration of sickness absences have been registered for workers in 30 plants of 17 member companies of The Japan Chemical Fibers and Textile Association (JCFTA). Diseases that caused absence were classified into 38 categories by plant physicians according to a simplified version of the International Classification of Diseases, and recorded monthly in the central file of JCFTA. Using 1982 data for 26, 324 male manufacturing workers including 13, 472 shift workers, incidences (inception rate) of diseases that caused absence and days lost due to them were studied in order to evaluate the effect of shift work. The incidence of peptic ulcer was significantly higher (rate ratlo=1.6) among shift workers as compared with day workers. The incidences of days lost due to other diseases in shift workers were almost equal to or lower than those in day workers.

Effects of ozone and brief exercise on specific airway conductance in man

Four normal male subjects were exposed to 0.9 ppm ozone with exercise for five minutes. Specific airway conductance (Gaw/Vtg) was increased by exercise and decreased by inhalation of ozone in most subjects, but these effects were small. Ozone inhalation with exercise resulted in a highly significant decrease of Gaw/Vtg. It would seem that a peak concentration of 0.9 ppm of ozone for five minutes produces adverse effects when the subject undertakes exxercise in it.

The relationship between air pollution and weather as stimuli and daily mortality as responses in Tokyo, Japan, with comparisons with other cities

Abstract A comparative, stimulus-response analysis of 3 yr of Tokyo daily mortality in relationship to air pollution and weather, has yielded significant relationships between abnormal environmental events (stimuli) and subsequent high (excess) mortality events (responses). The relationships between the magnitudes of these events and the nature of these events are similar to those found in New York. One can therefore generalize relationships between mortality and air pollution-weather over the many subsets of different environmental situations and mortality experiences.

ESTIMATION OF CARBON MONOXIDE HEMOGLOBIN LEVEL BY EXPIRED AIR

It is customary to measure the percentage of carbon monoxide hemoglobin (CO-Hb) in studying CO poisoning. There are a number of techniques for measuring CO-Hb, however, of which the procedures are usually very cumbersome, time-consuming and necessitating the preparation of blood samples. In the population survey, those methods are, therefore, thought to be inadequate. Ringold et al. developed a method to estimate the percentage of CO-Hb by measuring the concentration of CO in the expired air. In the present study the authors collected samples of expired air in polyvinyl bags (18 cm × 24 cm 0.1s0.15 mm thick) which had shown no significant CO losses for 2 days, according to Jones 20 second breath-holding method, and analyzed samples using a commercially available nondispersive infrared analyzer, Horiba Model LIA-2. Interferences by carbon dioxide and water vapor were avoided by means of soda lime and silica gel respectively. Blood CO-Hb percentage which was measured by Conway microdiffusion method well correlated to the expired air CO concentration in the range of lower concentrations. Medical students (119) were examined in relation to their cigarette smoking habits and the result showed that number of cigarettes smoked in a day had significant correlation with the CO concentration of the expired air. Average expired air CO concentrations of 276 school children in Tokyo on very fine days in autumn were 1.5-2.0 ppm in the ambient air with CO at about 1.0 ppm. On the other hand, school children (1383) in rural Japan in winter showed a little higher average expired air CO (3.0-5.5 ppm) regardless of the presence of heaters in the class room (ambient air CO at 0.5-3.0 ppm). This expired air CO is thought to be accumulated CO emitted from traditional rural Japanese heating. But a small amount of expired CO concentration which was higher than that of the ambient CO might be due to endogenous CO.

ACUTE MERCURY VAPOR POISONING

Four cases of atypical elemental mercury poisoning are reported each of which showing a sudden increase of urinary mercury excretion, which lasted for about 6 months, after 18th month from the exposure, although urinary mercury concentrations had been gradually decreased until 17th month after the mercury vapor exposure. The characteristic features such as tremor and kidney symptoms usually seen in elemental mercury poisoning were not observed in our four cases. Some patients showed concentric constriction of visual fields, hearing damage in high frequencies, ataxia and peripheral neuropathy which were frequently seen in the alkyl mercury poisoning. But, these signs were considered to be related to mercury vapor exposure, although some other agents might have produced such unusual symptoms. The reason for the sudden increase of urinary mercury for many months after the exposure was not explained in the present study.

THE MICRO ANALSIS OF FLUORINE BY THE LINEAR WASH-OUT TYPE OVEN AND ITS APPLICATION

A linear wash-out type oven was developed for micro determination of fluoride. The procedures are similar to the Weiszs ring oven technique but with higher sensitivity in detection and with more convenient operations. Organic substances were ashed with an oxygen combustion flask, and the fluoride was detected with alminium chromazrol S complex as the color regent following the recovery from coexisting interferences by the diffusion method. Concentration range from 0.08 to 4×105 ppm can be successfully quantitated with 90 per cent recovery, and the standard deviation relative to the expected amount of four repetitive measurements was less than 30 per cent. The method was applied to the fluoride determination in rice crops harvested in localities within 10 kilometers from an alminium refinery firm in Japan. Analytical results showed that the highest concentration was found in bran powder as up to 122 ppm, up to 32 ppm in full grains, and 2.91 ppm as average in cleared grains which is higher than 1.20 ppm as average in the rationed rice grains cleared Clear relations among fluoride concentration in crops and the distance of the harvested location from the alminium refinery discharging hydrogen fluoride were mentioned by the author with 16 rice samples surveyed in 2 years. Fuoride in cleared grain can easily be dissolved in water, and be vaporized and removed from grain on cooking. Average 240 μg of fluoride would be taken into human subject if 1500 g of the polluted rice was served in 3 meals a day, and yet the amount does not exceed the average intake of 180s240μg among normal adults in rural districts of Japan from rice 3 times a day, daily intake from total diet being estimated as approximately 1.6 to 2.1 mg.

ENVIRONMENTAL ASSESSMENT OF CARBON DISULFIDE EXPOSURE BY MEANS OF ACTIVE CARBON MASK

Atmospheric carbon disulfide concentrations in the working place and the amount of carbon disulfide inhaled during the normal work were estimated so that the relation between the industrial environment and the exposure to it was assessed. The former was determined by the diethylamine copper acetate method with fritted filter glass sampling tubes, and the latter by recovering absorbed carbon disulfide from the active carbon filter of a mask which was worn by workers during their normal work at a normal breathing flow rate. It was experimentally verified that the absorbed carbon disulfide was recovered almost hundred precent by extraction under the condition of hot water vapor pressure. In the field survey of viscose rayon factories, it was found that the recovered value well corresponded with the environmental concentration in the breathing zone and that there was the feasibility of utilization of such a mask in the industrial hygiene practice.

PULOMONARY PEAK PLOW RESPONSE TO ACID AEROSOLS AND BRONCHODILATOR IN INDUSTRIAL WORKERS

Twenty two workers who were exsosed to acid aerosols, hydrogen chloride mists in a electric applianced manufacture and sulfuric acid mists in a copper smelter industries were examined their pulmonary ventilatory peak flow rate comparing with 15 control subjects who were not accustomed to such irritant mists. Moistened acid aerosols were generated from hot acid bath, for pretreatment of galvanization, and their median aero sol diameter were measured as ca. 6 microns (HCl) and ca. 3 microns (H2SO4) in the respective plants by examining on a Gerhards thymol blue impregnated film sampled in a spiral sampler. Reading of peak flow rates by Wrights flow meter was made at three points in sequence: before exposure, after on hour of exposure during work and after bronchodilator (Isoproterenol) inhalation. The results summarized are as follows: 1. In control subjects the peak flow rate showed a remarkable decrease after entering acid aerosol environment in the both factories, about 9% decrease for HCl aerosols of 8.68mg/m3 and about 2% decrease for H2SO4 aerosols of 1.88mg/m3 while for the accustomed H2SO4 workers the response showed no significant change or even increase in some cases as shown in Fig.4 (B). This difference seems to be attributed to period of working experience and tolerance of the workers. Wright peak flow response was greater and more prompt in HCl aerosol workshop where the median diameter of the aerosols was large, than in H2SO4 aerosols with smaller diameter which includes considerable amount of submicron sized droplets. 2. Effects of bronchodilator during acid exposure showed the significant difference between the aerosol workers and the control group in the both environments; greater increase of peak flow rate in the control (16% for HCl, 5% for H2SO4 increase from the level of bronchostriction) than in the aerosol workers (2% rise for HCl, 1-3% rise for H2SO4). 3. Considering such factors as droplet size, chemical property, duration of working experience and behavior by bronchodilator, it may be concluded that H2SO4 aerosols of small particle with submicron size acts more persistent as bronchial irritant and results more chronic damage to respiratory tracts than larger sized HCl aerosols to which mainly the upper part of the airway is responded and the reaction is rather intense and momentary.

INDUSTRIAL HYGIENIC EVALUATION OF EXPOSURE TO CS2 THROUGH ANALYSIS OF BIOLOGICAL MATERIALS

From the environmental and medical records obtained by factory surveys in five staple fiber and artificial silk plants, average CS2 concentration in the spinning room, expired CS2 concentration of the workers during and after the day shifts, urine CS2 level in the following morning before entering the work, and clinical signs including subjective complaint and results of laboratory tests were summarized to evaluate the occupational exposure to CS2 with a view to industrial hygiene control.1, CS2 level of the expired air was gradually elevated during the shift and reached equillibrium to the environmental CS2 in about 3 hours. At the excreting stadium the expired CS2 level fell sharply in the first 20 minutes and continued tracing an exponential or parabolic curve. The form and the level of this curve was varied by the individual difference in accordance with the serum cholesterol level. An animal experiment revealed in this connection, that the coefficient o〓foo istribution of environmental vs. blood CS2 concentrations rose when the serum cholesterol level was elevated after four month exposure to CS2. 2. Threshold limit of the average CS2 concentration in the working place was estimated to be 15 ppm on 8 hour basis, when the free CS2 concentration in the morning urine before entering the shift showed a threshold level and expired CS2 concentration immediate after the shift was about 2 μg/dl. When values exceeds this level, various clinical signs and complaints as shown in Figure 4 began to be observed in several workers. As the indices of industrial exposure to CS2 values obtained by analyses of expired CS2 at the end of the shift and urine at the beginning of the following shift are extremely useful for evaluating the industrial hygiene practice and control in the viscose rayon industry.