It has long known that H₂S is sometimes encountered during excavation in the Hiroshima delta. In order to secure information necessary to the improvement of working conditions in this area, we investigated the generation of H₂S where work was being done on the Hiroshima sewage system.
Using the shield method, we measured the concentration of H₂S in the air around eight work sites, and we also measured pH, total sulfide, SO₄^2-, Cl^-, Mg²⁺, and salinity in samples of water collected at the sites and from nearby wells. The ventilation volume was calculated from the measurement value of air movement with reference to ventilator capacity. The past situation of H₂S generation at the sites was also investigated. The survey was conducted from August 30 to September 4, 1982, using the shield method.
Concentrations of H₂S from 0.8 to 7 ppm were detected in the air at four of the eight sites. Total sulfide varying from a trace to 8.5 mg/l was found at six sites, which included the four where H₂S was found in the air. SO₄^2-, Cl^-, and Mg²⁺ were found in high concentration in water in which sulfide was detected, and the same samples tended to have high salinity. At some of the sites, ventilation was implemented up to a maximum of 3, 000 m³/h according to the concentration of H₂S. At the sewage system construction sites covered in this survey, H₂S concentration was kept below the permissible level of 10 ppm, and it may be concluded that adequate safety precautions have been taken.

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作業環境中の有害ガスの個人モニターとしては活性炭ディスクに吸着させた環境ガスを二硫化炭素で抽出してガスクロマトグラフで定量する方法が提案されている.この方法は抽出液として二硫化炭素を用いるため,取扱い上および迅速性の面で問題があるので,われわれは,活性炭ディスクに吸着された成分を加熱脱着してガスクロマトグラフで直接的に定量する改良法を検討した結果,実用になりうることがわかったので報告する.
トルエン蒸気を用いた実験では,まず加熱脱着による分析の可能性を試験するために200 ppmのトルエン蒸気を用いて,特製パイレックスガラス容器(270 ml)中, 16時間活性炭ディスクと接触させてから,活性炭ディスクを細分し,各切片への吸着量を加熱脱着機能をもつガスクロマトグラフで定量した結果,活性炭ディスク中心部での値は,ほぼ満足すべきもので,この方法は改良法として用いうることがわかった.このため,試料蒸気と接触させた活性炭ディスクは16等分して,各切片に吸着された試料を分析することにし, 20, 40および80 ppmのトルエン蒸気に,それぞれ1週間曝した活性炭ディスクを用いて実験した.この結果から,実験値の平均値(W)とトルエン濃度(C)の間には直線関係があり, C=1.14×W(mg)と表現できることがわかった.ここでガスクロマトグラフのレコーダーでプリントアウトされる面積をAとするとW(mg)=5.024×10^-6Aの関係となる.蒸気濃度と曝露時間の関係,および加熱脱着部の改良による活性炭ディスク試料の大型化はさらに検討する必要がある.
3M Brand Organic Vapor Monitorを用いる場合は,対象ガスが活性炭に吸着でも,さらに, CS₂により変質せずに抽出できることが必要であるが,この条件に適合しない化合物として, CO, CH₄, C₂H₆, C₃H₈, CH₂-O-CH₂, CH₃OH, HCHO, CH₃Cl, H₂S, CH₃NH₂,(CH₃)₂-NH,(CH₃)₃N, RNCS,およびSO₂などがある.本改良法により,この点を改善できるか否かをしらべるためにメタノール蒸気を試験した.蒸気濃度を20, 40および80 ppmとして,トルエン蒸気の場合と同様に検討した結果,メタノール蒸気濃度に関係なく活性炭ディスクを16等分してからガスクロマトグラフで分析するまでの時間が短いほどよいことがわかった.これは,吸着されたメタノール蒸気が揮発しやすいことに原因すると考えられるので,測定までの時間がもっとも短い試料のデータをもとにして整理した結果,メタノール蒸気濃度(C)と実験値の平均値(W)の間には, C=1.19×W(mg)の関係があることがわかった.ここでAをトルエン蒸気の実験の場合と同様にとると, W(mg)=1.74×10^-9Aとなる.

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Six primary screening test items (grip strength, skin temperature, Nail-Press test, pain sense, and vibration sense at 125 Hz and at 250 Hz) for the vibration syndrome were assessed for validity and reliability using four measures: correlation with working time in years with vibrating tools; degree of relationship with four major complaints (Reynaud's phenomenon, numbness, coldness, and pain); correlation between two repeated examinations; values of t-test calculated on two groups of workers of comparable age, one having all of the four major complaints and the other having no complaint at all. Both left and right hand scores were used in the analysis with a total of 12 items. As these scores were too heterogeneous to make direct comparison, the screening items were ranked according to the values of the four measures and then the obtained ranks were totalled for each item to establish a further ranking. In this way, the ranks of each screening item were determined.
The results indicated that: 1) For validity, pain sense and 250 Hz vibration sense were found to have relatively high validity, followed by 125 Hz vibration sense and grip force. Skin temperature and the Nail-Press test occupied the lowest ranks. 2) For reliability, grip force and 250 Hz vibration sense were highest followed by pain sense. In this case again, skin temperature and the Nail-Press test turned out to belong to the lowest group, which included the 125 Hz vibration sense. 3) The right and left hand scores were separately analyzed and the right hand scores tended to surpass the left hand ones, although these comparison were not statistically significant (in 8 out of 12 comparisons, right hand scores were superior to left hand ones for validity, and for reliability it was the case for 9 out of 12 cases).
These results suggest that the two measures of the peripheral blood flow (i.e., skin temperature and the Nail-Press test) should be replaced by more reliable measures.

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日本国有鉄道の新幹線は,早朝から深夜まで過密ダイヤのもとで,高速度を出して走行している.したがって,新幹線車両の清掃労働者は主に,深夜労働に従事することを余儀なくされ,頻回な夜間勤務を行っている.本研究は,新幹線車両清掃労働者の健康に及ぼす夜間勤務の影響を検討したものであり,特に,連続夜勤の回数と健康障害の関係について評価を行った.本研究は二つの調査研究から成っている.
最初の研究では,勤務実態と健康実態を明らかにするため, 1か月間の夜動の頻度,連続夜勤の回数,自覚症状を調査した.調査は,大阪駅で働く246人の男性清掃労働者に対して,日本産業衛生学会交代勤務委員会作成の質問用紙を配布する方法を用いて, 1981年に実施した.調査結果は,勤務形態別に3グループに分けて比較検討を行った.
グループAは,夜勤専従者であり,勤務編成は,週に5回の連続夜勤を基本とする102人のグループである.グループBは,一昼夜交代で週3回勤務をする124人のグループである.グループCは,週6回勤務の日勤者20人である.これら勤務の形態別比較の結果,グループAにおける胃腸障害,全身疲労感の訴え率が最も高く現われていた.
最初の研究結果にもとづいて, 2番目の研究では,連続夜勤の回数と健康障害の関係について検討を行うため,ケース・コントロールスタディを行った.研究対象は,最初の研究で対象とした夜勤労働者の中から60人を5歳階層ごとに無作為抽出し, 3グループに分け各グループ20人ずつとし,方法は,産業衛生学会疲労研究会作成の疲労自覚症状を勤務の前後で1労働週にわたって自記させた. 3グループは,グループA20人,グループB20人,グループD20人である.グループAとBは,最初の研究の同じ勤務形態であるが,グループDは,グループAのコントロールとして,夜勤3日目を非番日に変えた勤務に従事させた.調査の結果,グループAとBでは最後の勤務後に疲労自覚症状の訴え数が第1日目の勤務前と比べて有意に増加していたが,コントロールのグループDでは訴え数の有意な増加は認められなかった.
これら二つの研究結果から,夜間勤務の形態と労働者の健康状態の間に密接な関連があり, 5連続夜勤の3日目を非番日にすることは,労働負担を軽減するうえで効果的であることが明らかとなった.したがって, 5回以上の連続夜勤に就労する新幹線清掃労働者の職業的健康障害を防止するためには,連続夜勤回数の頻度や労働時間に関する勤務条件の改善がなされるべきであると考えられた.

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In 9 series of physical examinations legally required for trichloroethylene (TCE) workers, levels of urinary total trichloride compounds (TTC) were revealed to be generally high in 323 specimens, including 250 male ones, collected from a medium sized company. Sixty four specimens (19.8%), including 56 male ones (22.4%), exceeded 300 mg/l which are regarded to correspond to the threshold limit for TCE in the air of the work site. Four specimens had over 900 mg/l. In all 323 specimens, however, no abnormalities were found with respect to specific gravity of blood, hemoglobin concentration and urinary tests.
TTC concentration values increased in specimens in the last 4 physical checkups, compared with the values measured in the first 5. The cause of this increase seemed to be related to increases in the number of products and the hours of overtime work.
Symptoms felt by these workers gradually subsided as they were continuously exposed to TCE for more than 2 or 3 years. Some workers of long service had a tendency toward addiction to TCE.
In the legally required environmental monitoring of TCE, and other harmful organic solvents, the 8 workplaces fell into either classification 1 or 2, indicating that the environmental conditions are not harmful. More importantly, the above evaluations did not take into account long hours of overtime put in by those workers.
Turning to the checkups of 1, 1, 1-trichloroethane workers, the results of legally required physical checkups and environmental monitoring were almost the same as those for TCE.
In conclusion, it is necessary to introduce a urinary TTC analysis in the screening test of the physical checkups for TCE or 1, 1, 1-trichloroethane.

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Platinum and its compounds have characteristics that make them excellent oxygen sensors, and in recent years they have come to be used in large amounts in the manufacture of internal combustion engines. Recently, there have been detected among workers engaged in making platinum oxygen sensors, dermatitis and bronchial asthma which appear to be ascribable to exposure to chloroplatinate. This is a study of their etiology from the viewpoint of industrial hygiene and clinical medicine. The results obtained are as follows:
1. Platinum-induced allergic disorders developed in a worker who applies about 50% chloroplatinate to zirconia porcelain. Although the concentration of platinum in the air was 2 μg/m³ or less as determined by ACGIH, the worker was directly exposed to the dried powder of ammonium chloroplatinate with relatively high concentration; while the exposure was intermittent and topical, it resulted in aspiration of the powder.
2. Bronchial asthma observed in 2 of 16 workers (12.5%) was reactive in a skin drop test with 1% chloroplatinate, and typical bronchial asthma was induced in an environmental provocation test carried out in a room where platinum sensors are made. Parameters obtained from periphero-hematological and immuno-serological tests were within the normal range.
3. The main symptoms revealed by physical examination of workers exposed to chloroplatinate contact dermatitis in 11 (78.6%), pharyngeal irritation in 6 (42.9%), nasal obstruction in 2 (14.3%), frequent sneezing, coughing, and sputum in one each. Diameter of the redness developed in a skin drop test with 1% chloroplatinate administered to 14 workers was 10 mm or more in 7 cases (50%).
VC, %VC, FEV 1.0, FEV 1.0%, PF/Ht, V25/Ht and MMF were within the normal range in a pulmonary function test.
Although periphero-hematological test results and leukograms were within the nomal range, an immuno-globulin test revealed abnormally high IgE level in one patient.
There was also observed an increased IgE level in one anamnesis of bronchial asthma. Immunoglobulin levels other than IgE were approximately within normal range.

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A vapor generator for multicomponent organic solvents was developed and its performance was investigated experimentally. The vapors were generated from the surface of a sintered sphere of glass beads containing the organic solvents. The solvents were automatically supplied from the solvent reservoir to the sphere by suction pressure caused by the evaporation of the solvents and the generated vapors kept at constant high concentration over a long period. The vapor concentration increased with the decreasing flow rate and the increasing gas temperature. The concentration ratio of the generated vapor was found to be equivalent to the mixing ratio of solvents in the reservoir, so this device can generate multicomponent organic solvent vapors at any concentration ratio. The vapor generator is simple to construct and is recognized to be useful for investigation of inhalation toxicities of multicomponent organic solvent vapors.

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A total of 1, 179 organic solvent products used as thinners, paint, degreasers, inks, adhesive and others, were collected nationwide from factories of various sizes and kinds in Japan, and analyzed by gas chromatography. Solvent components per sample, frequency of each solvent component, and contents of each component were analyzed and classified by use. Paints, inks, and adhesives which contained nonvolatile substances were analyzed by head space techniques. Seventy-seven percent of all samples, 93% of paints, 85% of thinners, 73% of adhesives, and 52% of degreasers contained mixed organic solvents. The average numbers of solvent components per sample were 4.14 (max. 13) in thinner, 3.29 (max. 7) in paint, 2.23 (max. 5) in ink, 2.19 (max. 6) in adhesive, 1.71 (max. 6) in degreaser, when gasoline was excluded. Toluene, xylene, methylalcohol, isopropylalcohol, ethylacetate, methylethylketone, industrial gasoline were widely used in the above-mentioned products. Toluene was the most popular component in the solvent products, excluding degreasers. Many kinds of solvent components were used in thinner and paint. However, toluene, xylene and industrial gasoline were their main components and contents per sample were very high. Acetates, alcohols, ketones and glycols were frequently detected in solvent products, but their contents per sample were relatively low, because these solvent components were usually used

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