• Journal of Environmental Science International
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• v.18 no.4
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• pp.401-409
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• 2009

The results of particulate matters level and heavy metal concentration, which surveyed in Gwang-Yang, Dang-Jin steel industry area, are as follows; The $PM_{2.5}$, $PM_{10}$ of exposure area are $22.3{\mu}g/m^3$, $40.4{\mu}g/m^3$ each in Kum-Ho dong, and $28.1{\mu}g/m^3$, 51.5 each in Jung dong. The $PM_{2.5}$, $PM_{10}$ of control area are $16.4{\mu}g/m^3$, $29.5{\mu}g/m^3$ each in Bonggang-myeon. The level is higher in exposure area than control area. In case of Dang Jin, the concentration of $PM_{10}$ and $PM_{2.5}$ is higher in exposure area than control area ($PM_{2.5}-20.4{\mu}g/m^3$, $PM_{10}-39.2{\mu}g/m^3$). The Pb level of Dang Jin area is higher in exposure area ($0.13{\mu}g/m^3$) than control area ($0.1{\mu}g/m^3$) and both Gwang-Yang and Dang-Jin area lower level than the Guideline level of Korea EPA.

• Safety and Health at Work
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• v.12 no.1
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• pp.127-132
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• 2021

Background: Herbicides such as glyphosate, paraquat, and 2,4-dichlorophenoxyacetic acid have been reported to cause adverse side effects through production of reactive oxygen species. However, there were no data representing the adverse effects of a mixture herbicide usage in farmers, especially the changes in oxidative marker and antioxidant defense. This study aimed to determine the urinary malondialdehyde (MDA) and glutathione (GSH) level in farmers using mixed herbicides. Methods: Ninety-three farmers were recruited, and two spot urine samples (before and after work) were collected. The urinary MDA level was evaluated by thiobarbituric acid reactive substance assay, and the urinary GSH level was determined using the enzymatic recycling method. Results: Sixty-two percent of the participants were men, and 59% of the participants worked in a farm for 20-40 years. The common combinations of herbicide usage were glyphosate with 2,4-dichlorophenoxyacetic acid (36.5%). There was no significant difference between pre- and post-work urinary MDA and GSH levels among the 3 groups of herbicides. However, the urinary MDA levels in farmers using the combination of glyphosate and paraquat were significantly higher than those found in farmers using glyphosate alone. The associated factors with changes in MDA levels found that the exposure intensity index (B = 0.154), the cumulative exposure intensity index (B = 0.023), and wearing gloves while working (B = -2.347) were found to be significantly associated with MDA level. Conclusion: The results suggest that the combined use of glyphosate and paraquat caused a significant increase in urinary MDA levels. Moreover, intensity of exposure to herbicide and wearing gloves were associated with the level of MDA.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1225-1233
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• 2024

Level 3 probabilistic safety assessment (PSA) is performed to calculate radionuclide concentrations and exposure dose resulting from nuclear power plant accidents. To calculate the external exposure dose from the released radioactive materials, the radionuclide concentrations are multiplied by two factors of dose coefficient and a finite cloud dose correction factor (FCDCF), and the obtained values are summed. This indicates that a standard set of FCDCFs is required for external exposure dose calculations. To calculate a standard set of FCDCFs, the effective distance from the release point to the receptor along the wind direction should be predetermined. The TID-24190 document published in 1968 provides equations to calculate FCDCFs and the resultant standard set of FCDCFs. However, it does not provide any explanation on the effective distance required to calculate the standard set of FCDCFs. In 2021, Sandia National Laboratories (SNLs) proposed a method to predetermine finite effective distances depending on the atmospheric stability classes A to F, which results in six standard sets of FCDCFs. Meanwhile, independently of the SNLs, the authors of this paper discovered that an infinite effective distance assumption is a very reasonable approach to calculate one standard set of FCDCFs, and they implemented it into the multi-unit radiological consequence calculator (MURCC) code, which is a post-processor of the level 3 PSA codes. This paper calculates and compares short- and long-range FCDCFs calculated using the TID-24190, SNLs method, and MURCC method, and explains the strength of the MURCC method over the SNLs method. Although six standard sets of FCDCFs are required by the SNLs method, one standard sets of FCDCFs are sufficient by the MURCC method. Additionally, the use of the MURCC method and its resultant FCDCFs for level 3 PSA was strongly recommended.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.1 no.1
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• pp.47-55
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• 1991

Exposure level of respirable coal dust of underground coal mines in Taebaek area was evaluated. Personal air samplers with 10-mm nylone cyclones were attached to the coal workers including drillers, coal cutters, their assistants, haulers, and separators. Log-normality of respirable dust exposure concentration were tested by Kolmogorov-Smirnov one-sample test. Differences of means of respirable dust exposure concentration between work sites were tested by one-way ANOVA test and multiple comparison(Scheffe) test. And differences of respirable dust exposure concentration of principal and assistant workers in drilling sites and in coal faces were tested by paired t-test. Relation of respirable dust exposure concentration for the principal workers and their assistants in drilling sites and in coal faces were tested by regression analysis. The results were as follows : 1. All of the respirable dust concentration were log-normally distributed. 2. There were not only significantly different means of exposure concentration between drillers and coal cutters but between coal cutters and haulers. 3. Means of exposure concentration of drillers and drilling assistants were not significantly different. And means of exposure concentration of coal cutters and coal cutting assistants were not different.

• Journal of Preventive Medicine and Public Health
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• v.47 no.5
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• pp.245-252
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• 2014

Arsenic is a unique element with distinct physical characteristics and toxicity whose importance in public health is well recognized. The toxicity of arsenic varies across its different forms. While the carcinogenicity of arsenic has been confirmed, the mechanisms behind the diseases occurring after acute or chronic exposure to arsenic are not well understood. Inorganic arsenic has been confirmed as a human carcinogen that can induce skin, lung, and bladder cancer. There are also reports of its significant association to liver, prostate, and bladder cancer. Recent studies have also suggested a relationship with diabetes, neurological effects, cardiac disorders, and reproductive organs, but further studies are required to confirm these associations. The majority of research to date has examined cancer incidence after a high exposure to high concentrations of arsenic. However, numerous studies have reported various health effects caused by chronic exposure to low concentrations of arsenic. An assessment of the health effects to arsenic exposure has never been performed in the South Korean population; thus, objective estimates of exposure levels are needed. Data should be collected on the biological exposure level for the total arsenic concentration, and individual arsenic concentration by species. In South Korea, we believe that biological exposure assessment should be the first step, followed by regular health effect assessments.

• Journal of Environmental Health Sciences
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• v.45 no.6
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• pp.569-576
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• 2019

Objectives: The main purpose of this study was to assess firefighters' daily personal noise exposure and explore noise levels related to specific tasks and their contributions to total noise exposure using 24-hour full-shift noise exposure measurements with task-based data. Methods: Noise exposure was assessed for eight firefighters (two rescuers, two drivers, and four suppressors) using time-activity diaries. We collected a total of 24 full-shift personal noise sample sets (three samples per a firefighter). The 24-hour shift-adjusted daily personal noise exposure level (L_ep,d), eight weekly personal noise exposures (L_eq,w), and 40 task-specific L_eq values (L_{eq activity}) were calculated via the ISO/NIOSH method. Results: The firefighter noise-sample datasets showed that most firefighters are exposed to noise levels above EU recommended levels at a low-action value. The highest noise exposure was for rescuers, followed by drivers and suppressors. Noise measurements with time-at-task information revealed that 82.3% of noise exposure occurred when checking equipment and responding to fire or emergency calls. Conclusions: The results indicate that firefighters are at risk of noise-induced hearing loss. Therefore, efforts at noise-control are necessary for their protection. This task-specific noise exposure assessment also shows that protective measures should be focused on certain tasks, such as checking and testing equipment.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.7 no.2
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• pp.161-170
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• 1997

This is an effort to confirm changes biological monitoring according to changes in levels of exposure to styrene for industrial workers. This study was conducted on 108 workers, including male of 64 and female 44 who were working at factories of FRP, dipping, and coating. An improved passive monitor method(organic vapor monitor; OVM) was employed to determine levels of exposure. The biological monitoring include blood styrene concentration, urinary mandelic acid(MA), and urinary phenylglyoxylic acid(PGA). Biological monitoring were made through the Collection of blood and urine. The mean value of exposure to styrene was 21.0ppm, which is measured by organic vapor monitor, one of improved passive monitors. The highest exposure level was observed among workers in boat factories, laminating procedure workers, processing workers, respectively(p<0.01). For exposure level, 11% of subjects under study showed over 50ppm which is time weighted average(TWA). The correlation coefficient between biological specimens and the exposure level was 0.62 for blood styrene concentration, 0.58 for MA corrected by creatinine, and 0.70 for PGA corrected by creatinine, respectively(p<0.01). The regression analyses found exposure level relative importance in explaining variance in biological monitoring. In additional to that, gender was a significant factor in explaining variance of MA and MA+PGA. Almost half of variance(49%) in blood styrene concentration was explained by predictors, including exposure level, age, gender, duration, and drinking volume during the last week(p<0.01). The very high correlation(higher than 0.95 was found when a comparison was made among three types of corrected methods, including uncorrected specific gravity and creatinine. In conclusion, these findings suggest OVM to represent levels of exposure to styrene for industrial workers. A discussion was made on possible use of specific gravity sample for biological monitoring. Exposure level may be predicted on MA, PGA in urine, which could be applied to represent biological monitoring.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.1
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• pp.74-78
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• 2014

Objectives: Purpose of this study was to evaluate the noise level exposures at the different cannonball type and locations in the tank gun drill ranges. Methods: We visited the tank gun drill ranges and measured with a sound level meter(3M Quest SoundPro$^{TM}$) with the value of Peak(dB(A)). Results: The highest peak value of impulse noise level averaged 166.3 dB(A) at the site of loading solider. The highest peak value of impulse noise level by size of cannonball averaged 165.9 dB(A) at the 120 mm size cannonball of the tank. This result was significantly different from the other size of cannonballs such as 7.62 mm, 90 mm, and 105 mm(p < 0.001). Among the four types of soldier site on the tank, average noise levels of loading soldier, 156.6 dB(A), were higher than the other three types of soldier site (p > 0.05). Conclusions: This study confirmed that there were needed for a proper control to reduce the amount of impulse noise exposure at the tank gun drill ranges.

• Journal of Korean Society for Atmospheric Environment
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• v.4 no.1
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• pp.23-32
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• 1988

The exposure level of respirable dust and silica for the coal workers of underground coal mines in Taebaek area was evaluated. Personal air samplers were attached to the coal workers-drillers, coal cutters, their helpers, haulers, and separators. Normality and lognormality of respirable dust and silica concentrations were tested by Kolmogorov-Smirnov one-sample test, differences of means of respirable dust and silica concentration were tested by group-t-test and paired t-test, and relation between respirable dust and silica concentration were tested by regression test.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1884-1887
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• 1997

The increasing concern over radiation exposure in the nuclear industry has fostered agrressive efforts to reduce the levels of radiation exposure. One area of the effot to reduce the radiation exposure is the development of a remote radiation monitoring system. Remote radiation monitoring can serve many benificaial functions reduce exposure to radiation by plant personnel, impruve the quality of the data that is collected and recognize the radiation environment easily. Radiation mapping system gives a good information that represents radiation level distribution. The system we have developed consists of a data acquistion parts, mobile robot and remote control parts. Data acquisition parts consist of radiation detection module and vision acquistion module which collect radiation data, visiion data and distance information. In remote control parts, the acquision data are processed and displayed. We have constructed radiation mapping image by overlaying the vision and radiation data. The radiation mapping techniques for displaying the results of the survey in an easily comprehendable form will facilitate a better understanding of the radiation environment in the facility. This system can reduce workers radiation exposure and aid to help work plan, so it has significant benifits in cost and safety.