• Journal of Korean Society of Occupational and Environmental Hygiene
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• 제10권1호
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• pp.126-146
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• 2000

To develop and evaluate formaldehyde measurement method using 2,4-dinitro-phenylhydrazine (2,4-DNPH) coated sampler and gas chromatography, laboratory test and field test were conducted. Results of this study are as follows. Limit of detection(LOD) of measurement methods, HPLC-UVD, GC-NPD and GC-FID, is $0.008{\mu}g/m{\ell}$ $0.060{\mu}g/m{\ell}$, $0.472{\mu}g/m{\ell}$ respectively. Coefficiency of measurement methods, HPLC-UVD, GC-NPD and GC-FID, is 0.008, 0.009, 0.020 respectively. Desorption efficiency of sep-pak xposure aldehyde sampler and sorbent sample tube is 1.05(range : 0.99 - 1.12), 1.02(range : 0.99 - 1.06) respectively. Samples of sorbent sample tube and sep-pak xposure aldehyde sampler turned out to be stored at refrigerator, according to storage test results. Measurement methods of HPLC-UVD, GC-NPD, GC-FID, according to results of precision for the combined sampling and analytical procedure, became acceptable to OSHA evaluation standard. Field test using exposure chamber met the NIOSH overall uncertainty recommendation(less than 25%). Overall uncertainty of Sepak-HPLC(UVD), Tube-GC(NPD), Tube-GC(FID) is 11.0% - 17.0%. Consequently gas chromatography(GC-NPD, GC-FID) and high performance liquid chromatography(EPA TO-11) using 2,4-DNPH coated sampler for formaldehyde measurement turned out to be suitable to measure personal formaldehyde exposure at workplaces.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• 제20권3호
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• pp.203-215
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• 2010

This study is an overview of toxicities and measurement techniques of ultrafine particles (UFPs), and their exposure controls. UFPs are ubiquitous in many working situations. Exposure to UFPs is possibly causing adverse health symptoms including cardio-respiratory disease to humans. In order to measure exposure levels of airborne UFPs, there are current available measurement guidelines, instruments and other techniques (i.e. contour mapping, control banding). However, these risk assessment techniques including measurement techniques, controls and guidelines are dependent on background levels, metrics (e.g. size, mass, number, surface area, composition), environmental conditions and controls. There are no standardized measurement methods available and no generic and specific occupational exposure standards for UFPs. It is thought that there needs to be more effort to develop Regulations and Exposure Standards for generic UFPs should be based on more exposure data, health surveys, toxicological data and epidemiological data. A carefully considered hierarchy of controls can also reduce the maximum amount of airborne UFPs being emitted from diverse sources in industries.

• Journal of the Korean Society of School Health
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• 제34권1호
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• pp.33-41
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• 2021

Purpose: Exploring the variables that predict teachers' intent when referring students to mental health professionals is important. The Theory of Planned Behavio (TPB) is a theory of predicting people's intentions of performing a particular behavior; the intent to perform a certain behavior is determined by three factors. (1) attitudes toward the behavior, (2) subjective norms, and (3) perceived control. This study aimed to develop a TPB measurement to investigate what variables predict the intentions of teacher's referral behaviors. Methods: A qualitative study following standardized manuals and guidelines for developing a TPB measurement was used. As a qualitative research method, the Consensual Qualitative Research-Modified (CQR-M) was used. According to the findings from the qualitative study, the quantitative measurement to assess teachers' referral intention, attitude, subjective norm, and behavioral control was developed. Results: The reliability and validity of the newly developed measurement were tested and verified. Conclusion: The newly developed measurement would contribute to a future empirical study that will examine predictors of teachers' referral intention.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• 제31권4호
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• pp.440-450
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• 2021

Objectives: This study aims to investigate whether working environment measurement institutions(WEMIs) are conducting safety and health education, risk assessment, and oversight of special management materials, and whether working environment measurement and special medical examinations are being conducted as prescribed in the Occupational Safety and Health Act(OSHA). Methods: In of February 2021, a questionnaire was prepared and distributed to 33 WMEIs registered with the Ministry of Employment and Labor(MoEL) in Busan and Gyeongsangnam-do Province. The responses were collected and then analyzed. Results: The findings show that 5 WEMIs(15%) complied fully with OSHA. Risk assessment was conducted by 13 WMEIs(39%) and safety education by 11 WMEIs(33%). Eighteen WMEIs(55%) conducted working environment measurement, and 29 WMEIs(88%) conducted special medical examinations. The implementation rate of the risk assessment in the health industry(85%) was higher than the one in the special technology industry(11%)(p<0.05). The implementation rate of the special medical examination in the examiners(54%) was not as high as the one in the analysts(91%)(p<0.05). Conclusions: The MoEL needs to check whether basic OSHA requirements are being observed during regular inspections by WEMIs. These findings indicate that it is necessary to prepare a plan to improve the rate of compliance with OSHA regulations.

• Safety and Health at Work
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• 제7권4호
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• pp.381-388
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• 2016

Background: Relationships among portable scanning mobility particle sizer (P-SMPS), condensation particle counter (CPC), and surface area monitor (SAM), which are different metric measurement devices, were investigated, and two widely used research grade (RG)-SMPSs were compared to harmonize the measurement protocols. Methods: Pearson correlation analysis was performed to compare the relation between P-SMPS, CPC, and SAM and two common RG-SMPS. Results: For laboratory and engineered nanoparticle (ENP) workplaces, correlation among devices showed good relationships. Correlation among devices was fair in unintended nanoparticle (UNP)-emitting workplaces. This is partly explained by the fact that shape of particles was not spherical, although calibration of sampling instruments was performed using spherical particles and the concentration was very high at the UNP workplaces to allow them to aggregate more easily. Chain-like particles were found by scanning electron microscope in UNP workplaces. The CPC or SAM could be used as an alternative instrument instead of SMPS at the ENP-handling workplaces. At the UNP workplaces, where concentration is high, real-time instruments should be used with caution. There are significant differences between the two SMPSs tested. TSI SMPS showed about 20% higher concentration than the Grimm SMPS in all workplaces. Conclusions: For nanoparticle measurement, CPC and SAM might be useful to find source of emission at laboratory and ENP workplaces instead of P-SMPS in the first stage. An SMPS is required to measure with high accuracy. Caution is necessary when comparing data from different nanoparticle measurement devices and RG-SMPSs.

• Investigative Magnetic Resonance Imaging
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• 제20권4호
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• pp.207-214
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• 2016

Purpose: The purpose of this study was to investigate the effect of the number of measurement points on the calculation of transverse relaxation time (T2) with a focus on muscle T2. Materials and Methods: This study assumed that muscle T2 was comprised of a single component. Two phantom types were measured, 1 each for long ("phantom") and short T2 ("polyvinyl alcohol gel"). Right calf muscle T2 measurements were conducted in 9 healthy male volunteers using multiple-spin-echo magnetic resonance imaging. For phantoms and muscle (medial gastrocnemius), 5 regions of interests were selected. All region of interest values were expressed as the mean ${\pm}$ standard deviation. The T2 effective signal-ratio characteristics were used as an index to evaluate the magnetic resonance image quality for the calculation of T2 from T2-weighted images. The T2 accuracy was evaluated to determine the T2 reproducibility and the goodness-of-fit from the probability Q. Results: For the phantom and polyvinyl alcohol gel, the standard deviation of the magnetic resonance image signal at each echo time was narrow and mono-exponential, which caused large variations in the muscle T2 decay curves. The T2 effective signal-ratio change varied with T2, with the greatest decreases apparent for a short T2. There were no significant differences in T2 reproducibility when > 3 measurement points were used. There were no significant differences in goodness-of-fit when > 6 measurement points were used. Although the measurement point evaluations were stable when > 3 measurement points were used, calculation of T2 using 4 measurement points had the highest accuracy according to the goodness-of-fit. Even if the number of measurement points was increased, there was little improvement in the probability Q. Conclusion: Four measurement points gave excellent reproducibility and goodness-of-fit when muscle T2 was considered mono-exponential.

• Journal of Environmental Health Sciences
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• 제37권1호
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• pp.73-79
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• 2011

The growing interest in nanotechnology has resulted in increasing concern and a number of published environmental and workplace measurements for assessing occupational exposure to engineered nanomaterials. However, the amount of previous exposure data remains limited. Furthermore the data available was collected with extensive variation in terms of exposure measurement strategy, which limits the ability to pool the data in the future. In response, this paper reviewed several pertinent issues related to exposure measurement strategy to suggest a harmonized measurement strategy which would make exposure data more useful in the future, e.g. correlation between exposure metrics, relationship between activity and exposure, task-based or shift-based assessment, background concentration, limitation of personal exposure monitoring and other determinants of exposure/modeling. An improved sampling strategy for nanomaterial exposure assessment should be considered in order to maximize the use of the data from various real time monitoring instruments.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• 제32권4호
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• pp.456-464
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• 2022

Objectives: The Purpose of this study is to improve work environment measurement in construction industry by survey. Especially, this study focused on the defferences between construction staffs(safety manger, health manager) and work environment measurement institution workers. Methods: Survey targets are construction staffs(safety manger, health manager) and work environment measurement institution workers. Respondent was selected by respective councils and conferences. A questionnaire consisting of items on general characteristics and the improvement of work environment measurement in construction industry. Results: Total of 134 people(39 safety managers, 27 health managers, 68 work environment measurement institution workers) responded to survey. Overall, current work environment measurement was deemed unsuitable for construction industry. There was a significant difference between construction staff and work environment institution workers in some question. On the other hand, there was no noticeable significant difference in general characteristics. Conclusions: As a result of survey, current work environment measurement was deemed unsuitable for construction industry in terms of measurement method, measurement timing, and actual site improvement. In addition, there is a statistically significant differences in response between construction staff and work environment measurement institution workers, so it is necessary to reflect both opinions in order to improve work environment measurement in construction industry.

• International Journal of Safety
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• 제7권1호
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• pp.26-29
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• 2008

The purpose of this study is the measurement of whole-body vibration for different road surfaces. Experimental measurements were taken on asphalt, cement, and off-road surfaces as defined by ISO 2631-1. Each experiment was conducted under the same set of conditions (measurement duration, times, speed, vehicle type). Measurement duration was 10 minutes and 3 separate measurements were taken on each road surface. Vehicle speed was 60km/h. In accordance with ISO 2631-1, an acceleration sensor is set up between the driver's seat and the human body. For evaluation, RMS(root-mean-square) values were taken as suggested by ISO 2631-1. The results suggest "health guidance caution zones", and the evaluation was based on obtaining the vector sum with "health guidance caution zones".

• Journal of Korean Clinical Health Science
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• 제10권2호
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• pp.1587-1593
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• 2022

Purpose. This study was to investigate the degree of refractive error that occurs depending on the measurement location of the subject when performing a refraction test using the automatic refractor. Methods. When performing the auto-refraction test, measurements were taken while increasing the distance between the forehead and the forehead rest, and the measurements were made by tilting the head clockwise and counterclockwise. Results. During the auto-refraction test, significant refractive error occurred when the forehead was not attached to the forehead support or the subject's head was turned clockwise or counterclockwise. Conclusions. When performing a refraction test using an automatic refractor, the examiner will have to pay attention to whether the subject's forehead is in close contact with the forehead rest, and whether the head is tilted.