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Effects of Acute Xylene Exposure on the Enkephalinergic Neuromodulatory System in Rats
J.M.DE GANDARIAS, E.ECHEVARRIA, E.CASIS, L.MARTINEZ-MILLAN and L.CASIS
Abstract : Xylene is a neurotoxic organic solvent widely used in industry. However, the neurochemical mechanism of its action on the central nervous system is to date relatively unknown. In this work, the effect of subacute xylene exposure on met-enkephalin like immunostaining in different brain regions is described. Acute treatment with xylene generates a reduction in immunostaining for met-enkephalin in the globus pallidus, the olfactory tubercule and the hypothalamic medial preoptic area, without changes in the parietal cortex, caudatus-putamen and the central amygdaloid nuclei. It is suggested that enkephalins could play a role in xylene neurotoxic mechanism in the brain.

Evaluation of Work Stress Using Psychological and Physiological Measures of Mental Activity in a Paced Calculating Task
Shizue KURIMORI and Toshio KAKIZAKI
Abstract : With a view to developing a method of evaluating mental work stress, a paced calculating task (addition and subtraction of two two-digit figures) with eight grades of workload (20%-160% of work capacity) was assigned to 21 male and 20 female students. Using a VDT, subjects performed the task and psychological and physiological measures of mental activity (intellectual activity,feeling, arousal level) were determined. Occipital midline (Oz)B2 (20 Hz-30 Hz) amplitudes regressed linearly against workloads, with a marked rise observed at overload levels (above 100% workload), though the number of correct responses did not increase at such levels. Error rate, subjective task difficulties, and feelings (unpleasant, tense, excited) were proportional to workload and closely correlated to each other. Blood pressures and heart rates increased slightly in proportion to workload, with a correlation between them. Feelings were presumed to be not particularly intense even at overload levels. Regression coefficients of error rate, excitement level, and OzB2 amplitude were larger in females than males. Based on the results, it was inferred that females might sustain somewhat more severe work stress than males. Critical flicker frequencies decreased over time. The criteria for evaluating heavy and excessive mental work stresses were deduced from the OzB2 amplitudes, which best reflected intellectual activity, and from the critical flicker frequency, which is related to arousal level.

Results of Pneumoconiosis Examination --Different Trends among Industries--
Toshiaki SHINOZAKI and Eiji YANO
Abstract : In this report we describe yearly changes in pneumoconiosis patients and pneumoconiosis progression in each industry in Japan, using statistics of Ministry of Labour based on the results of pneumoconiosis examinations performed at plants in accordance with the Pneumoconiosis Law. We found that the number of workers exposed to mineral dust decreased yearly. The number of subjects with positive findings, the number of new cases with pneumoconiosis, the ratio of positive findings, and the incidence rate of pneumoconiosis also decreased. In particular, the number of subjects with positive signs of pneumoconiosis clearly decreased. A similar tendency was seen in the number of cases including voluntary applications. Industry-wise, however, there was a large difference among the industries. The ratio of pneumoconiosis with complications, along with the progression ratio, decreased. Subjects with progressed pneumoconiosis decreased annually, exhibiting less-serious signs and symptoms. There have been reports with a different view about the general trend of pneumoconiosis. We examine and discuss the cause of discordance between the studies.

A Mouse Model of a Sudden Death Induced by Noise Exposure is Useful to Investigate Human Responses to Physical Stress
Yasuhiko WADA, Takashi MOGI, Hiroshi INOUE and Akio KOIZUMI
Abstract : Stress has become an increasingly important occupational health matter in Japan. We found that noise exposure, 6 kHz wave and its higher harmonics at the sound pressure level of 112 dB, induced typical audiogenic seizures in the MRL/l mouse strain. The seizures are often fatal. Wild running preludes to seizures. Inhibition of wild running by restricting animal's activities successfully prevented the seizures, suggesting that an excessive physical load is a necessary step. The present finding indicates that MRL/l mice may be a useful model for human sudden deaths after excessive work loads.

A Questionnaire Survey on the Use of Dust Respirators among Lead Workers in Small Scale Companies
Yoko AIBA, Keiko KOBAYASHI, Jun SUZUKI, Yoko SHIMIZU, Midori NISHIMURA, Norihiro SASAKI, Shigenori MAKINO and Tadao UTUNOMIYA
Abstract : In order to find out whether dust respirators are properly used among lead workers in small scale manufacturing companies of lead pigments and stabilizers, a questionnaire survey was carried out for 141 lead workers. The questionnaire consisting of 7 items of questions including selection, use, maintenance, storage and instruction of respirators was distributed to all 141 workers. This survey revealed that 22% of the total workers wore unauthorized dust respirators, and that 73% used a knitcover. Instruction by health supervisors of how to use and where to store the respirators was found to be effective for inspection of valve and a proper place to store dust respirator. However, the result that significantly large percentage of workers used the knitcover following the health supervisors' instruction can be taken to indicate that health supervisors should be given more precise information on deteriorated face-sealing of the respirator facepiece with the knitcover.

Ocular Surface Area as an Informative Index of Visual Ergonomics
Midori SOTOYAMA, Maria Beatriz G.VILLANUEVA, Hiroshi JONAI and Susumu SAITO
Abstract : A large ocular surface area (OSA) is thought to be one of the causes of eye irritation and eye fatigue. Because ocular surface is very sensitive to various irritants such as dust, heat, dryness, air flow, etc, a large OSA increases the possibility of eye surface exposure to such irritants. Thus, OSA is one of the most important indices of visual ergonomics. This paper aims at making OSA an exact and practical index by first describing an accurate method of measuring it, and then clarifying the relationship between OSA, the width of the palpebral fissure, and vertical gaze direction, all of which are thought to be strongly correlated with each other. We derived the following equations: 1)     y = 0.039 x1 + 3.36, r = 0.99, 2)     y = 3.05 x2 - 0.39, r = 0.97, 3)     x1 = 72.7 x2 - 91.4, r = 0.97, where x1 = vertical gaze direction (degrees),     x2 = width of the palpebral fissure (cm)     y = OSA (cm2). Finally, this paper also introduces the practical applications of OSA measurement, and notes the differences between OSA when VDT work (word processing using a keyboard and drawing a picture using a mouse) is performed and when traditional office work without a VDT (reading, drawing, and writing) is performed.

Circadian Rhythm of Catecholamine Excretion in Rats after Phase Shift of Light-Dark Cycle
Ayako SUDO and Keiichi MIKI
Abstract : To clarify the time course of circadian rhythm adaptation to a phase shift of the light-dark (LD) cycle, urinary excretion of catecholamines was measured in rats before and after a 12-hour or 6-hour phase delay of a 12-hour light and 12-hour dark schedule. In rats under a basal condition, distinct circadian rhythms in catecholamine excretion were observed, especially in adrenaline excretion. During the 1st and 2nd days after a 12-hour phase delay, the acrophase and amplitude of adrenaline rhythm remained almost unchanged, but thereafter the acrophase was retarded and the amplitude was reduced. The acrophase once again became constant after 5 or 6 days, but the ratio of amplitude to mesor in the circadian rhythm of adrenaline excretion and the ratio of light-period to 24-hour noradrenaline excretion were readjusted to the new LD schedule on 11th or 12th day. In the 6-hour phase delay of the LD cycle, similar findings were observed, and the results suggested adaptation on the 5-6th day. It is considered that the circadian rhythms of the sympathetic adrenomedullary function are restored, at the latest, 12 days after a 12-hour delay of the LD cycle, and 6 days after a 6-hour delay, suggesting that rats need approximately 1 day to adapt to a 1-hour phase shift.

A Prospective Study on Mortality among Japanese Coal Miners
Hiroshi UNE, Hiroji ESAKI, Kenichi OSAJIMA, Haruhiko IKUI, Kayo KODAMA and Kazunori HATADA
Abstract : We conducted a prospective study to clarify mortality patterns among Japanese coal miners in a former coal mining area. Subjects included 1,796 coal miners and 4,022 non-coal-miners, who were identified by a mail survey between 1987 and 1989, and then followed up from the date of the survey to April 30th, 1994. We applied Cox' s proportional hazards model to compare the mortalities between coal miners and non-coal-miners. Among the coal miners, significantly high risk ratios were observed in all causes of death (risk ratio = 1.4, p < 0.05) and all malignant neoplasms (risk ratio = 1.5, p < 0.05). Risk ratios for all causes of death and all malignant neoplasms also rose with the length of experience in coal mining. Analysis of the results for sites of cancer showed that coal miners had high risk ratios for stomach cancer (risk ratio = 1.6), liver cancer (risk ratio = 1.4) and lung cancer (risk ratio = 1.6), though these ratios were not statistically significant. When the risk ratio for lung cancer was analyzed according to the length of experience in coal mining, coal miners with at least 15 years' experience had a significantly high risk ratio (risk ratio = 2.4, p < 0.05), though coal miners with less than 15 years' experience had almost the same risk as non-coal-miners.

Effects of Marital Status and Position on Personality Traits in Engineers of a Computer Manufacturing Plant
Satoko EZOE, Shunichi ARAKI, Yutaka ONO, Norito KAWAKAMI and Katsuyuki MURATA
Abstract : To investigate the effects of marital status and position on DSM-III-R personality traits, we administered the self-rating questionnaires of the Structured Clinical Interview for DSM-III-R Personality Disorders to 757 male computer engineers, aged 20 to 49 years, at a computer manufacturing plant. The scores for six of eleven personality traits were significantly higher in the single computer engineers than in the married ones. Also, among the engineers aged 40 to 49, the scores for six personality traits of the section-heads were significantly higher than those among persons in the other positions. These findings suggest that "maladaptive" personality traits, defined by the DSM-III-R, differ with marital status and position in a company.

Efficacy of Liposome Encapsulated Triethylenetetraamine Hexaacetic Acid (TTHA) against Cadmium Intoxication --Role of Lipid Composition--
Sanjay GUPTA, Jai Raj BEHARI, Sadhna SRIVASTAVA, Minakshi MISRA and Ramesh C.SRIVASTAVA
Abstract : Efficacy of Triethylenetetramine hexaacetic acid (TTHA) encapsulated in liposomes having different lipid compositions was examined in animals pre-exposed to cadmium. Mice were injected with cadmium as cadmium (II) chloride 0.5mg/kg b. wt.) intraperitoneally daily for five days. Four weeks after the last injection of cadmium they were administered three injections of TTHA encapsulated in liposomes composed of either phosphatidyl choline: cholesterol (PC:Chol) or sphingomyelin:cholesterol (SM:Chol) in 1:1 molar ratio at a gap of 48 h. Urinary and fecal elimination of cadmium and its distribution in liver, kidneys and spleen was examined. Treatment with TTHA encapsulated in liposomes mobilized higher amount of cadmium from liver and spleen. The overall efficiency for cadmium mobilization was better in TTHA encapsulated in SM: Chol liposome treated group which also led to enhanced excretion of cadmium through urine and feces. The results indicate that TTHA encapsulated in SM:Chol liposomes exhibited highest efficacy in mobilizing cadmium from the body of pre-exposed mice followed by PC:Chol liposomes and the free drug.

Vibrotactile Temporary Threshold Shifts Induced by Hand-transmitted Vibration during Underwater Work
Setsuo MAEDA, Yoshiharu YONEKAWA, Kazuo KANADA, Yukio TAKAHASHI and Michael J.GRIFFIN
Abstract : The purpose of this paper is to clarify the temporary threshold shifts (TTS) of fingertip vibratory sensation produced by hand-transmitted vibration in an underwater work environment. The hand-transmitted vibration was applied with a pneumatic tool to the right hand of four experienced male SCUBA divers. The threshold of 125 Hz vibratory sensation was measured at the tip of the right forefinger before and after vibration exposure in the atmosphere and underwater. Vibration exposure at a 4 m depth produced greater TTS than in the atmosphere. The recovery time of TTS after vibration exposure in an underwater were affected by the underwater pressure.

Some Aspects of Occupational Safety and Health in Green Tea Workers
Seyed Mohammad MIRBOD, Setsuya FUJITA, Kazuhisa MIYASHITA, Ryoichi INABA and Hirotoshi IWATA
Abstract : The objectives of this study were to evaluate the health and safety conditions of 36 male and 27 female green tea workers who were aged 40-69 years and had worked for at least 5 years in green tea production procedures. The Mean ± SD of age was 57.1 ± 5.8 years in males and 54.4 ± 6.4 years in females. The mean working career was 26.1 ± 9.5 years and 24.3 ± 9.1 years, respectively. The most commonly subjective complaints developed while at work was pain in the lower back at a rate of 72.2% in males and 63.0% in females. Regarding persistent subjective complaints, female workers had significantly (P < 0.05) higher prevalence rate for breath shortness (25.9%) compared to that of male workers (5.6%). It was observed that the male workers whose occupational career was equal to or more than 28 years had significantly higher prevalence rates for stiffness in the neck and pain in the arms, compared to those of male workers whose occupational career was less than 28 years. The prevalence of nasal allergy was 11.1% either in the male or female workers. The total rate of accidents during working hours in the male workers was 22.2%, and that in the female subjects was 18.5%. The mean frequency weighted vibration magnitude produced by using tea-leaf plucker was in the range of 2.4-3.5 m/s2. The mean equivalent A-weighted noise level while using the same equipment was 100.6 ± 5.0 dB(A). The need for occupational safety and health programs in these small farm settings are discussed.

Acute Effects of Inhalation Exposure to Carbon Monoxide on Schedule-controlled Operant Behavior and Blood Carboxyhemoglobin Levels in Rats
Muneyuki MIYAGAWA, Takeshi HONMA, Mitsuo SATO and Hiromichi HASEGAWA
Abstract : The acute effects of carbon monoxide (CO) exposure on a steady-state operant behavior (bar-pressing under a VI 60-sec schedule of food reinforcement) were repeatedly measured in (a) rats exposed to various concentrations of CO (500, 1,000, 1,500 and 2,000 ppm) for 1 h and (b) rats exposed to 1,500 ppm for different periods (1, 2 and 4 h). Measurements were made continuously before, during and after the exposure period. Abrupt cessation of the response was produced by exposure to 1,000 ppm or higher concentrations of CO. Recovery from the effects of CO exposure was observed as sudden resumption of responding during the post-exposure period. The duration of exposure required to produce response inhibition was closely correlated with the exposure concentration. The post-exposure interval required for response recovery was also correlated with the exposure concentration. This post-exposure response recovery interval, however, was constant and independent of the duration of exposure when the concentration was fixed at 1,500 ppm. In order to correlate these behavioral changes with an internal index of CO exposure, blood carboxyhemoglobin (HbCO) levels were determined under several exposure conditions corresponding to those of the behavioral observations. It was found that HbCO levels were within a certain range (33-43%) when response recovery occurred, suggesting the existence of a critical HbCO level (threshold) associated with the drastic behavioral change. Hence, these results support the view that blood HbCO is an important determinant of the acute behavioral effects of CO.

Effect of Long and Short Fibre Amosite Asbestos on In Vitro TNF Production by Rat Alveolar Macrophages --The Modifying Effect of Lipopolysaccharide--
Shashi DOGRA and Kenneth DONALDSON
Abstract : The influence of long and short fibre amosite on the generation of tumor necrosis factor (TNF) by rat alveolar macrophages was investigated in vitro. TNF rich supernatants were prepared from macrophages cultured in F10 medium +2% Bovine Serum Albumin (BSA). Spontaneously released TNF from unstimulated macrophages and TNF rich supernatants from macrophages exposed to Lipopolysaccharide (LPS) and fibres were stored at -70 degrees centigrade and then tested for their cytotoxicity towards L929 cells. Maximum spontaneously released TNF was obtained from 24 hour macrophage cultures. Short amosite fibres had no significant effect in stimulating alveolar macrophages to release TNF while the 50 ug dose of long fibres resulted in significantly increased release of TNF. Co-treatment of alveolar macrophages with LPS and fibres further enhanced the TNF production and maximum production was obtained with LPS +50 ug dose of long fibre resulted in significantly increased release of TNF. Co-treatment of alveolar macrophages with LPS and fibres further enhanced the TNF production and maximum production was obtained with LPS +50 ug of long fibre amosite. The present study indicates that fibre dimension is a major factor in in vitro dust activity and TNF has a possible active role to play in dust induced inflammation in vivo.

Exacerbation of Nickel Induced Oxidative Response by Vitamin E
Mirza M.HUSAIN, Nihal AHMAD, Sanjay GUPTA, Jai R.BEHARI, Syed K.HASAN, Sanjay K.SRIVASTAVA and Ramesh C.SRIVASTAVA
Abstract : Vitamin E (a-tocopherol), a well known naturally occurring chain breaking antioxidant and a free radical scavenger was found to exacerbate nickel (Ni) toxicity in mice. Vitamin E (Vit. E) mediated enhancement of nickel toxicity was demonstrated by (i) enhanced mortality in mice treated with Ni and Vit. E (ii) increased hepatic lipid peroxidation, (iii) increased rate of benzoate hydroxylation, and (iv) liposomal membrane damage.

Effects of Mood States, Smoking and Urinary Catecholamine Excretion on Hemoglobin A1c in Male Japanese Workers
Norito KAWAKAMI, Shunichi ARAKI, Hisashi OHTSU, Takeshi HAYASHI, Takeshi MASUMOTO and Kazuhito YOKOYAMA
Abstract : To know the association between psychological strain and glycosylated hemoglobin (HbA1c) and to examine roles of smoking and catecholamine excretion as a possible mediator in the association, we measured mood states (Profile of Mood States, POMS), urinary catecholamines (adrenalin, noradrenalin and dopamine) from urine sample in early moring, HbA1c and fasting plasma glucose (FPG) of 63 male employees on a rest day. After excluding 12 subjects who had diabetes or impaired glucose tolerance or had missing response to the questionnaire, data from 51 subjects were analyzed. The POMS anger-hostility score significantly and positively correlated with HbA1c (p<0.05), while other scale scores did not (p<0.05). Number of cigarettes smoked per day significantly and positively correlated with HbA1c (p<0.05). Urinary excretion rate of any catecholamine did not significantly correlate with HbA1c (p<0.05). Multiple linear regression analysis indicated that the anger-hostility score significantly correlated with HbA1c after controlling for number of cigarettes per day (p<0.05). It is suggested that, among mood states, anger-hostility is associated with increased HbA1c. However, our study failed to find a mediating role of urinary catecholamines or smoking on the association between the mood and HbA1c.

Dyspnea and Exercise testing in Workers Exposed to Silica
Xiaorong WANG, Shunichi ARAKI, Eiji YANO, Mianzheng WANG and Zhiming WANG
Abstract : In order to provide a better objective assessment of exertional dyspnea and functional impairment due to exposure to silica, 153 workers exposed to silica dust (workers) and 62 patients with silicosis (patients) were performed the medical questionnaires with special reference to exertional dyspnea and exercise testing on bicycle ergometer. Complaints of breathlessness were present in 77(50%) workers and 53(85%) patients. The findings of exercise tests indicated that there were definite correlations between index of dyspnea(ID), or breathing reserve (BR) and complaint of breathlessness in both the workers and patients. ID increased and BR decreased with the increasing degree of breathlessness. We defined ID&>70% or BR <25L/min as abnormal criteria and checked the ratios of dyspnea quantified objectively. Thus, 30% of the workers and 56% of the patients in this study were verified to have slight or moderate breathlessness, which were considerably lower than that derived from questionnaire on dyspnea. Our results suggest that objective physiological measures like exercise testing may be of value in evaluatng dyspnea in workers exposed to silica.

Effects of Smoking on Respiratory Function and Exercise Performance in Asbestos Workers
Xiaorong WANG, Shunichi ARAKI, Eiji YANO, Mianzheng WANG and Zhiming WANG
Abstract : To determine the role of smoking in the development of pulmonary impairment in asbestos workers, 66 nonsmoking asbestos workers and 70 smoking asbestos workers were studied. Occupational and medical questionnaires, lung function and exercise test were conducted in all subjects. The frequencies of dyspnea and cough on questions were significantly higher in the smoking workers than those in nonsmoking workers. Similarly, FEV1, FEV1/FVC and DLco were significantly lower in the smoking workers. Exercise performance showed that the smoking workers had higher index of dyspnea and lower breathing reserve, Vo2 and Vo2max than nonsmoking workers did. We concluded that cigarette smoking has marked effects on both of respiratory function and exercise performance in asbestos workers. Among them, smokers show more serious obstructive impairment in static lung function testing and more significant limitation during exercise. The history of cigarette smoking deserves close attention in the evaluation of pulmonary impairment from asbestos exposure.

Assessment of Interlaboratory Performance on the Measurement of Blood Lead Levels in Taiwanese Adults
Saou-Hsing LIOU, Guang-Yang YANG, Trong-Neng WU, Ying-Chin KO, Yue-Liang GUO, Shien-Tsong HO, Jim-Shoung LAI, Yea-Quay WU, Horn-Che CHIANG, Kquei-Nu KO and Po-Ya CHANG
Abstract : The purpose of this proficiency study was to assess the accuracy and consistency of blood lead level (BLLs) measurements in a study of Taiwanese adults. Three methods, including a certified blood accuracy test, an interlaboratory precision test and an intertime repeated measurement test, were applied to the six participating laboratories. Accuracy tests showed that most of the blood lead measurements were within the acceptable criteria proposed by United States Center for Disease Control and Prevention (U.S. CDC). However, an average of 11% underestimation was found at BLLs below 15 μg/dl. Coefficients of variation (CVs) were high in the first 3 months. After technical improvements, the CVs were reduced to acceptable limits of around 15% at low target lead values and 7% at high lead values. Interlaboratory variations of measurements in blood from ten normal healthy donors showed that the standard deviations were less than 2 μg/dl, which is within the acceptable criteria of ± 4 μg/dl, in 8 out of 10 samples. Repeated measurements of BLLs in 54 blood samples over two months showed that most of the differences were within the acceptable range with a few exceptions. The mean BLLs measured in the baseline (pre-test) and two months later (post-test) were nearly identical. This proficiency test provides comparable and reliable results of BLL estimations in this multilaboratory study. However, the accuracy and consistency at low BLLs need to be improved.

Accidents in the Aluminium Smelting Industry
Bhuban C.DAS and Susama CHAUDHURY
Abstract : Analysis of the accident records of an aluminium smelting industry, covering about 2100 employees, over a period of three years, showed a total of 465 accidents of male employees. Out of these, 5 were fatal, 40.86% were from contacts with extreme temperatures, causing burn injury to 42.58%. Hot materials were the agents causing 44.52% of the burn injuries. Molten aluminium constituted 43.96% amongst hot materials. Injury to lower limbs constituted 38.71% and that to upper limbs 36.99%. The accidents occurring to the employees, in the age group of 26-33 years, amounted to 61.72% of the total accidents. The average number of man%days lost per year was 11153. Average frequency rate of accidents was 30.75 accidents per million man%hours worked. Severity rate of accidents was 2196 per million man%hours worked. Incident rate per thousand employees was 73.81. Average number of days lost per accidents was 71.95 days and average duration of man%hours between accidents was 32516. Mean age of the employees, who met with the accidents were 29.53 years. Share of accidents in the second half of each shift was always more than that in the first half, and this average was 66.66%.

Elevation of Cystathionine g-lyase Activity in the Serum of Rats Treated with a Single Dose of Carbon Tetrachloride
Tetsuya TAGUCHI, Shiro AWATA, Michiko NISHIOKA, Yukiko ARAKAWA, Noriyuki SHIRAISHI, Shuhei RYU, Hideo KUMAZAWA, Yasuo TAKANO, Kazuko NAKAYAMA, Kenichi YAGYU, Mami KAWAMURA and Atsushi SATO
Abstract : Cystathionine g-lyase activity in the sera of rats subjected to experimental hepatotoxicity after intraperitoneal administration of carbon tetrachloride (CCl4) was measured and compared with activities of aspartate aminotransferase (GOT) and alanine aminotransferase (GPT), which have been clinically used for detecting liver damage. In the experimental subjects, serum levels of cystathionine g-lyase showed a similar behavior to GOT and GPT, increasing markedly with respect to the controls after administration of CCl4 and reaching a maximum at 24 hours. No such cystathionine g-lyase activity was detected immunochemically in the control sujects. These data suggest that measurement of serum cystathionine g-lyase activity could be used as a sensitive and specific marker of hepatic cytolysis.

A Small-Volume Constant-Flow Air Sampling Device for Thermal Desorption GC Analysis
A Small-Volume Constant-Flow Air Sampling Device for Thermal Desorption GC Analysis
Abstract : A glass syringe with disposable membrane filters was tested as a constant-flow air sampling device. The principle of this sampling device is straight forward: when the syringe is inverted vertically, the syringe plunger falls at a constant speed if an appropriate flow restrictor is connected at the syringe inlet. In case of a 100 ml syringe with two Teflon membrane filters of 0.50 um in pore size and 3 mm in diameter, the flow rate was 3 ml/min. The flow rate was constant for a 15-minute sampling period when two to eight filters were used as a flow restrictor. A sample volume of less than 50 ml is sufficient for the determination of organic solvent vapor at the ppm level, when gas chromatography with thermal desorption method is employed. Therefore, this sampling device is useful for determining the time-weighted average concentrations of organic solvent vapor in a working environment.