• Journal of Preventive Medicine and Public Health
• /
• v.33 no.3
• /
• pp.306-312
• /
• 2000

Background : Polycyclic aromatic hydrocarbons (PAH) are well known environmental pollutants. The measurement of PAH in ambient air is not commonly used, because it is quite difficult to perform and is unreliable. Using biomarkers of PAH can be an alternative approach to this problem. The PAH in ambient air is absorbed in particulate matter. Total suspended particulate(TSP) or particulate matter of less than $10{\mu}m$ in diameter (PM10) can be easily measured. Therefore, TSP or PM10 can be used as a surrogate measurements of ambient air PAH. Objectives : We investigated whether the urinary concentration of two biomarkers of PAH, 1-hydroxypyrene (1-OHP) and 2-naphthol, could reflect the total suspended particulate in the general population. Methods : In order to exclude the effects of occupational exposure and smoking, first grade middle school students were included in this study. Four middle schools within a one kilometer boundary of ambient air monitoring stations were selected. Total suspended particulate was regarded as the marker of airborne PAH. Diet and smoking data were collected by self administered questionnaires, and spot urine samples were collected. Urinary 1-OHP and 2-naphthol were analyzed by high performance liquid chromatography. Results : The correlation between urinary 1-OHP, 2-naphthol and passive smoking was not statistically significant. The correlation between urinary 1-OHP and TSP indices was not statistically significant. The correlations between urinary 2-naphthol and TSP of two lag days, one lag day, and zero lag days were statistically significant. The statistical significance of two lag days was the strongest (p=0.001), one lag day was the next (p=0.0275), and zero lag days was the weakest (p=0.0349). Conclusion : Our results imply that the urinary concentration of 2-naphthol can be applied as a PAH exposure marker for the general population with low PAH exposure.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.11
• /
• pp.788-794
• /
• 2020

This study was measured and analyzed from January to November 2019 to confirm the effect that Abietic acid, an asthma-causing substance, which can be exposed to workers in the electronics industry, is removed by plasma treatment. The experiment was carried out using a solder wire and natural rosin. Air at temperatures of 250℃, 300℃, and 350℃ was collected with a glass fiber filter paper using an air sampler for 10 minutes at a flow rate of 2ℓ/min. An analysis of the collected samples was performed by pretreatment with methyl alcohol and quantitative analysis by high performance liquid chromatography (HPLC). This procedure confirmed that abietic acid was generated in both natural rosin and solder wires, and the quantum of abietic acid increased as the treatment temperature increased. The amount of abietic acid was higher in natural rosin than solder wire. As a result of plasma treatment, a removal efficiency of about 92% or more was confirmed in natural rosin. A peak of abietic acid was not detected in the solder wire. Therefore, a removal efficiency of 100% was confirmed. This study, confirmed that abietic acid, an asthma-trigger can be generated in solder wire and natural rosin, and can be removed by plasma treatment.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.11 no.1
• /
• pp.34-41
• /
• 2001

Passive samplers have been used for personal, indoor, and outdoor air monitoring of VOCs at ppb concentrations in community and office environments. The path length of modified passive sampler was shortened, so it was intended to increase an uptake rate. The performance of the modified 3M 3500 organic vapor monitor(OVM) as a tool for assessing exposures to toxic air pollutants in nonoccupational community environments was evaluated using combined controlled test atmospheres of six selected target volatile organic compounds(VOCs): benzene, methyl tert-butyl ether(MTBE), chloroform, 1,4-dichlorobenzene, tetrachloroethylene, and toluene. The experiments were conducted by exposing the dosimeters to concentrations of $50{\sim}100{\mu}g/m^3$ on six face velocity(0.00, 0.02, 0.06, 0.12, 0.20, 0.30 m/sec) for 24 hours. If the uptake rate was increased, that means that we could use the passive sampler more effectively. The uptake rates were increased linearly according to reduce the path length. Although the diffusion path length was shortened, the change of uptake rate was within ${\pm}25%$ of theoretical value, indicating that the modified passive sampler(TM) can be effectively used over the range of concentrations and environmental conditions tested with a 24-h sampling period if the face velocities were over 0.12 m/s for 6 components of VOCs. But when the face velocities were less than 0.12 m/s, uptake rates were reduced more than expected values. So, the passive sampler with the shortened path length should be used at indoor or outdoor environment where the face velocity should be over about 0.10 m/s. If the path length was shortened more, the uptake rate was more effected by starvation.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.6 no.1
• /
• pp.1-16
• /
• 1996

This study was conducted at an automobile assembly line located in Kyonggi-do, Korea from January 16 to February 28, 1995. The purposes of this study were to assess worker exposures to hand-arm vibration and the performance of gloves for reduction of vibration. The exposure to vibration was measured using to the ISO 5349(1986) method. Vibration acceleration and frequency spectra for each tool were determined on-line replicating actual working conditions and analyzed together with exposure time for evaluating individual worker exposure. Eight pneumatic hand tools, 60 workers exposured to hand-arm vibration, and three pairs of gloves were involved in this study. Results are summarized as follows. 1. Dominant frequencies of vibration for all tools(n=8) measured in this study ranged from 250 Hz to 800 Hz. 2. There was no significant correleration between dominant frequencies and free running speed (p>0.05). 3. Total predicted exposure times of using impact, hammer type did not exceed 40 minutes, but metal finish task, using grinder and sander exceeded 40 minutes. Total exposure time affected significantly the frequency-weighted, 4 hr equivalent acceleration. 4. Predicted prevalence and observed exposure period data were compared in workers(n=60), according to ISO 5349. In this results, 23(50.0 %) and 24(48.07 %) persons exceeded the mean latency periods for vibration-induced white finger(VWF) at 10 % (n=46) and 50 % (n=52) standards, respectively. On the basis of ISO equation, mean latent periods for VWF were 3.23, 4.72 years at 10 %, 50 % standards, respectively. 5. Reduction of vibration by gloves was evaluated. Since impact pneumatic tools produced low frequency vibrations, conventional gloves did not provide any protection. Gloves A and C amplify somewhat the signal at frequency below 400 Hz; the attenuation increases progressively by frequency to reach 18 dB ($7.94{\times}10^{-6}m/s^2$) at 1,000 Hz, slightly worsening Glove B did not provide any protection and made the situation slightly worse. However, since they make the hands warm, the occurrence of vibration-induced white fingers may be reduced.

• Journal of the Korean Society of Radiology
• /
• v.7 no.5
• /
• pp.305-311
• /
• 2013

This study involves an experiment using functional magnetic resonance imaging(fMRI) to delineate brain activation for execution functional performance. Participates to this experiment of the normal adult (man 4, woman 6) of 10 people, is not inserts the metal all closed phobia and 24.5 year-old average ages which the operating surgeon experience which are not they were. The subject for a functional MRI experiment word -color test prosecuting attorney subject rightly at magnetic pole presentation time of 30 first editions and after presenting, uses SPM 99 programs and the image realignment, after executing a standardization (nomalization), a difference which the signal burglar considers the timely order as lattice does, pixel each image will count there probably is, in order to examine rest and active crossroad dividing independence sample t-test (p<.05). Overlapped in this standard anatomic image and got a brain activation image from level of significance 95%. With functional MRI resultant execution function inside being relation, the prefrontal lobe, anterior cingulate gyrus, parietal lobe, orbitofrontal gyrus, temporal lobe, parietal lobe was activated. The execution function promotes a recovery major role from occupational therapy, understanding about the damage mechanism is important. When confirms the brain active area which accomplishes an execution function brain plasticity develops the cognitive therapeutic method which is effective increases usefully very, will be used.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.2
• /
• pp.293-301
• /
• 2018

This study examined the effects of a multifaceted intervention program on the psychological condition, empowerment, work readiness, and functional capacity for job performance of industrially injured workers. Twelve injured workers in C hospital were included in this study. The subjects participated in a social rehabilitation program 2 hours a day, twice a week, for 8 weeks in total, as well as a work hardening program 3 to 4 hours a day, 5 times a week, for 8 weeks in total. The study was conducted from March to September, 2017. A multi-dimensional psychological examination, empowerment scale, work readiness interview and functional capacity evaluation were conducted and the test scores compared before and after the program with the Wilcoxon signed rank test. In the multi-dimensional psychological examination, there were significant differences in the levels of anxiety, depression, lack of social support, and somatization symptoms (p<.05) except anger. The participants also showed significant differences in the empowerment scale, work readiness scale, and functional capacity evaluation. This study suggests that a multifaceted intervention program can be effective in improving the psychologic condition, empowerment, work readiness, and functional capacity of industrially injured workers and, in turn, may improve their rate of returning to work.

• The Journal of the Korea Contents Association
• /
• v.18 no.7
• /
• pp.536-550
• /
• 2018

This paper examine how acceptance of AI robots can be achieved according to occupational groups when the discourse on human labor and occupation changes due to the new industrial revolution is spreading steadily. Previous research on the acceptance of new technologies and products has predicted use behavior through subjective beliefs and values that do not change well over the short term. Therefore, this study compares the beliefs, values, and use intention of AI robots according to occupation. As a result, the subjective belief factor for AI robots was classified into belief in rationality(reason) and belief in benevolence(emotion). The value factors were divided into acceptance value(role performance, communication, social comparison) and avoidance value(risk, complexity). There was a significant difference in the effect of these on the use intention of AI robot by occupation and employment types. This result suggests that there are gaps in the occupation group at the rate of technology acceptance, as opposed to the existing prediction that AI robots will be rapidly expanded by professionals.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.5
• /
• pp.467-474
• /
• 2017

To investigate the intra-rater absolute reliabilities and validity of the Figure of-Eight Walk test (F8WT) in patients with chronic stroke. A total of 36 subjects with chronic stroke participated in this study. The inter-rater reliability of F8WT was calculated using intra-class correlation coefficients($ICC_{2,1}$). Moreover, we used the standard error measurement (SEM) and the small real difference (SRD) to examine the absolute reliability indices. The validity was demonstrated by a spearman correlation of F8WT with Postural Assessment Scale for Storke(PASS) and Trunk Impairment Scale(TIS). The inter-rater reliability of F8WT was excellent; ICC2,1=0.95(0.91~0.97), acceptable SEM=1.02, and SRD=2.82. F8WT were also found to be significantly associated with PASS(r=-0.82) and TIS(r=-0.85). Therefore, F8WT is a reliable measurement tool and is correlated well with stroke-impairments, such as postural and trunk control. F8WT will be a useful tool in evaluating the walking performance of subjects with chronic stroke.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.15 no.1
• /
• pp.1-7
• /
• 2005

Although the Fourier Transform Infra-Red spectrophotometric Direct on Filter(FTIR-DOF) method is a useful analytical technique for quantifying quartz content in respirable dust samples, a number of analytical problems must be taken into consideration such as, to name only a few, inhomogeneous deposition of particles, level of environmental humidity, uneven surface of the filter, and interfering minerals in the sample. This study was designed to select the most suitable wavelength and proper filter material for the method, and to investigate effects of humidity and inhomogeneous deposition of particles on the filter. Samples of respirable dust, created in a dust chamber containing standard material of quartz, were collected using a cyclone equipped with a 25mm filter as a collection medium. The results were as follows; 1. Among seven (7) commercially available filters tested for the FTIR-DOF method, the DM 800 filter showed the best analytical performance having the lowest background absorbance bands and no overlapping peaks at 799, 779, and $695cm^{-1}$. 2. The variations of absorbance due to humidity ranged from 1.0% to 3.3% for $799cm^{-1}$, 1.0% to 3.3% for $779cm^{-1}$, and 8.9%~20.9% for $695cm^{-1}$ peaks, respectively. The $699cm^{-1}$ peak was proved to be most vulnerble to environmental humidity for quantitative analysis of quartz. 3. As for effects of inhomogeneous deposition of samples, the highest variation of absorbance of 10.9% ($13.5{\mu}g$) was observed when using the 695cm-1. The variations of absorbance from the other two peaks, 799 and $779cm^{-1}$, ranged from 1.2 to 3.2%, and 1.4 to 4.1%, respectively. Therefore, the $799cm^{-1}$ peak was considered to be most reliable for quantitative analysis of quartz. The results of this study suggest that, for quantitative analysis of quartz in the respirable dust samples, use of the $799cm^{-1}$ peak can minimize the influence of environmental humidity and inhomogeneous deposition of particles on the filter. The FTIR-DOF method, if adopted for routine analysis of quartz in the respirable dust samples, could save sample preparation time and efforts substantially and also could increase analytical throughputs. Since use of the $799cm^{-1}$ peak is prone to be affected by interferences in the sample, further research on minimizing the effects is needed.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.10
• /
• pp.995-1002
• /
• 2016

The aim of this study was investigated the effect of orofacial exercise program using smart phone on swallowing function and tongue strength in acute stroke patients with dysphagia. This study participated in sixteen acute stroke patients with dysphagia. All subjects allocated that randomized each eight patients in experimental and control groups. Subjects of both group received to conventional dysphagia therapy during 30 min/day, 5 times per week, for 4 weeks. Experimental group performed additionally that orofacial exercise program using smart phone, supervised under caregivers, during 30 min/day. The outcome measures were the IOPI(: Iowa Oral Performance Instrument), VR(: Vellecula Residue), PSR(: Pyriform Sinuses Residue), MIP(: Maximum Isometric Pressures). In results of study. Both group showed significant improvements after intervention in all assessments(p<.05). In comparison of change score between two groups, experimental group showed significant improvements than control group in PSR and MIP(p<.05). Orofacial exercise program using smart phone suggested that expected to positive effects the reduction of residue in pharynx and improvements of tongue strength in acute stroke patients with dysphagia.