• 한국소음진동공학회논문집
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• 제25권1호
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• pp.5-12
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• 2015

According to the analysis of special medical examination and work environment monitoring data, the rate of C1 and D1 on noise hazard exceeded 90 % among those of total hazardous factors. The rate of company exceeding noise exposure limit was also more than 90 %. The analysis result shows that main ages diagnosed with C1 and D1 was age of 50s. The majority scale company having workers diagnosed with C1 and D1 was the companies employing 5~49 workers. Types of industries which have a large number of companies exceeding noise exposure limit were automobile and trailer manufacturing, metal processing industry and primary metal manufacturing. A large number of work processes exceeding noise exposure limit were forming and processing work, cutting and bending work and grinding. To reduce the number of company exceeding noise exposure limit, the reduction counterplan should be focused on the type of industry and the work process which exceeded noise exposure limit frequently. However, the reduction counterplan is preemptively necessary to the type of industry and the work process which exceeded noise exposure limit consecutively if the purpose of reduction counterplan is not to merely reduce the number of company exceeding noise exposure limit but to abate workers' suffering from noise.

• 한국환경보건학회지
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• 제45권3호
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• pp.258-266
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• 2019

Objectives: In this study, blood lead was analyzed using graphite furnace atomic absorption spectrometry (GF-AAs) and inductively coupled plasma mass spectrometry (ICP-MS). We tried to examine the difference and consistency of the analytical values and the applicability of the analytical method. Methods: We selected 57 people who agreed to participate in this study. After confirming the linearity of the calibration standard curves in GF-AAs and ICP-MS, the concentrations of lead in quality control material and samples were measured, and the degree of agreement was compared. Results: The detection limit of the ICP-MS was lower than that of GF-AAs. The coefficient of variation of reference materials was shown to be stable in the ICP-MS and GF-AAs. When the correspondence between the two equipments was verified by bias of the analysis values, a concordance was shown, and approximately 98% of the ideal reference lines were present within ${\pm}40%$ of the deflection. Conclusion: GF-AAs showed high sensitivity to single heavy metal analysis, but it took much time and showed higher detection limit than ICP-MS. Therefore, it would be considered necessary to switch to ICP-MS analysis method, considering that the level of lead exposure is gradually decreasing.

• Journal of Radiation Protection and Research
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• 제31권4호
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• pp.197-201
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• 2006

Daily and seasonal variations of the ambient gamma ray exposure rates were measured by using a pressurized ion chamber from January 2003 to December 2005 in the CheongJu Regional Radiation Monitoring Post and the patterns of the distributions were studied. The annual average of the daily variation of the exposure rate was $\sim0.17{\mu}R/h$. The exposure rate was found to be maximum during 8:00 am to 9:00 am and minimum during 8:00 pm to 10:00 pm. For the annual data, the exposure rate was the minimum during the month of February. The exposure rate increased from February to mid-October (except during the period from May to July with no change) and decreased from October to February. The seasonal variation was found to be about $1{\mu}R/h$. Most of the measured values (96%) of the exposure rates fell under the normal distribution with a deviation of less than 4.8% and the remaining 4% had large fluctuations caused mainly by the rainfalls.

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.13.1-13.4
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• 2016

An analysis of patients and fatalities due to exposure to polyhexamethylene guanidine (PHMG) shows that PHMG causes mainly lung diseases such as pulmonary fibrosis. However, no research on the other organs has been conducted on this matter yet. So, an in-depth discussion on toxicological techniques is needed to determine whether or not PHMG is toxic to organs other than just the lungs. For the test of target organ toxicity by PHMG exposure, a toxicokinetic study must first be conducted. However, measurement method for PHMG injected into the body has not yet been established because it is not easy to analyze polymer PHMG, so related base studies on analytical technique for PHMG including radio-labeling chemistry must come first. Moreover, research on exposure-biomarker and effect-biomarker must also be conducted, primarily related to clinical application. Several limitations seem to be expected to apply the biomarker study to the patient because much time has passed after exposure to the humidifier disinfectant. It is why a more comprehensive toxicological researches must be introduced to the causality for the victims.

• 한국멀티미디어학회논문지
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• 제23권11호
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• pp.1435-1445
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• 2020

Advertising is a communication that aims to persuade you through communication. Local governments are enforcing a lot of budget for outdoor advertisements and exposing advertisements to various media. However, in the case of outdoor advertisements, advertisements are executed without considering the specificity of the exposure environment, so it is inferior to the budget input. Therefore, this study aims to help local advertisement agents, producers, and related parties by classifying components by combining video analysis methodology and video ad analysis methodology for effective message delivery and immersion in local outdoor advertising. As a discussion to provide an efficient production methodology for outdoor advertising video production in the future, it is an extension of exploratory research through content analysis.

• BMB Reports
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• 제36권1호
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• pp.1-11
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• 2003

The causative role of polycyclic aromatic hydrocarbons (PAH) in human carcinogenesis is undisputed. Measurements of PAH-DNA adduct levels in easily accessible white blood cells therefore represent useful early endpoints in exposure intervention of chemoprevention studies. The successful applicability of DNA adducts as early endpoints depends on several criteria:i.adduct levels in easily accessible surrogate tissues should reflect adduct levels in target-tissues, ii. toxicokinetics and the temporal relevance should be properly defined.iii. sources of inter- and intra-individual variability must be known and controllable, and finally iv. adduct analyses must have advantages as compared to other markers of PAH-exposure. In general, higher DNA adduct levels or a higher proportion of subjects with detectable DNA adduct levels were found in exposed individuals as compared with non-exposed subjects, but saturation may occur at high exposures. Furthermore, DNA adduct levels varied according to changes in exposure, for example smoking cessation resulted in lower DNA adduct levels and adduct levels paralleled seasonal variations of air-pollution. Intra-individual variation during continuous exposure was low over a short period of time (weeks), but varied significantly when longer time periods (months) were investigated. Inter-individual variation is currently only partly explained by genetic polymorphisms in genes involved in PAH-metabolism and deserves further investigation. DNA adduct measurement may have three advantages over traditional exposure assessment: i. they can smooth the extreme variability in exposure which is typical for environmental toxicants and may integrate exposure over a longer period of time. Therefore, DNA adduct assessment may reduce the monitoring effort. ii. Biological monitoring of DNA adducts accounts for all exposure routes. iii. DNA adducts may account for inter-individual differences in uptake, elimination, distribution, metabolism and repair amongst exposed individuals. In conclusion, there is now a sufficiently large scientific basis to justify the application of DNA adduct measurement as biomarkers in exposure assessment and intervention studies. Their use in risk-assessment, however, requires further investigation.

• Safety and Health at Work
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• 제8권2호
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• pp.130-142
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• 2017

Background: Osteoarthritis of the knee is considered to be related to knee straining activities at work. The objective of this review is to assess the exposure dose-response relation between kneeling or squatting, lifting, and climbing stairs at work, and knee osteoarthritis. Methods: We included cohort and case-control studies. For each study that reported enough data, we calculated the odds ratio (OR) per 5,000 hours of cumulative kneeling and per 100,000 kg of cumulative lifting. We pooled these incremental ORs in a random effects meta-analysis. Results: We included 15 studies (2 cohort and 13 case-control studies) of which nine assessed risks in more than two exposure categories. We considered all but one study at high risk of bias. The incremental OR per 5,000 hours of kneeling was 1.26 (95% confidence interval 1.17-1.35, 5 studies, moderate quality evidence) for a log-linear exposure dose-response model. For lifting, there was no exposure dose-response per 100,000 kg of lifetime lifting (OR 1.00, 95% confidence interval 1.00-1.01). For climbing, an exposure dose-response could not be calculated. Conclusion: There is moderate quality evidence that longer cumulative exposure to kneeling or squatting at work leads to a higher risk of osteoarthritis of the knee. For other exposure, there was no exposure dose-response or there were insufficient data to establish this. More reliable exposure measurements would increase the quality of the evidence.

• Environmental Analysis Health and Toxicology
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• 제10권1_2호
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• pp.21-35
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• 1995

Risk assessment processes, which include processes for the estimation of human cancer potency using animal bioassay data and calculation of human exposure, entail uncertainties. In the exposure assessment process, exposure scenarios with various assumptions could affect the exposure amount and excess cancer risk. We compared risk estimates among various exposure scenarios of vinyl chloride, trichloroethylene and tetrachloroethylene in tap water. The contaminant concentrations were analyzed from tap water samples in Seoul from 1993 to 1994. The oral and inhalation cancer potencies of the contaminants were estimated using multistage, Weibull, lognormal, and Mantel-Bryan model in TOX-RISK computer software. In the first case, human excess cancer risk was estimated by the US EPA method used to set the MCL(maximum contaminant level). In the second and third case, the risk was estimated for multi-route exposure with and without adopting Monte-Carlo simulation, respectively. In the second case, exposure input parameters and cancer potencies used probability distributions, and in the third case, those values used point estimates(mean, and maximum or 95% upper-bound value). As a result, while the excess cancer risk estimated by US EPA method considering only direct ingestion tended to be underestimated, the risk which was estimated by considering multi-route exposure without Monte-Carlo simulation and then using the maximum or 95% upper-bound value as input parameters tended to be overestimated. In risk assessment for volatile organic compounds, considering multi-route exposure with adopting Monte-Carlo analysis seems to provide the most reasonable estimations.

• Environmental Analysis Health and Toxicology
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• 제27권
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• pp.5.1-5.10
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• 2012

Objectives: The purpose of this study was to assess the risk of ingestion exposure of lead by particle sizes of crumb rubber in artificial turf filling material with consideration of bioavailability. Methods: This study estimated the ingestion exposure by particle sizes (more than 250 um or less than 250 um) focusing on recyclable ethylene propylene diene monomer crumb rubber being used as artificial turf filling. Analysis on crumb rubber was conducted using body ingestion exposure estimate method in which total content test method, acid extraction method and digestion extraction method are reflected. Bioavailability which is a calibrating factor was reflected in ingestion exposure estimate method and applied in exposure assessment and risk assessment. Two methods using acid extraction and digestion extraction concentration were compared and evaluated. Results: As a result of the ingestion exposure of crumb rubber material, the average lead exposure amount to the digestion extraction result among crumb rubber was calculated to be $1.56{\times}10^{-4}$ mg/kg-day for low grade elementary school students and $4.87{\times}10^{-5}$ mg/kg-day for middle and high school students in 250 um or less particle size, and that to the acid extraction result was higher than the digestion extraction result. Results of digestion extraction and acid extraction showed that the hazard quotient was estimated by about over 2 times more in particle size of lower than 250 um than in higher than 250 um. There was a case of an elementary school student in which the hazard quotient exceeded 0.1. Conclusions: Results of this study confirm that the exposure of lead ingestion and risk level increases as the particle size of crumb rubber gets smaller.

• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.523-528
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• 2013

Background: The possibility that electromagnetic fields (EMF) exposure may increase male breast cancer risk has been discussed for a long time. However, arguments have been presented that studies limited by poor quality could have led to statistically significant results by chance or bias. Moreover, data fo the last 10 years have not been systematically summarized. Methods and Results: To confirm any possible association, a meta-analysis was performed by a systematic search strategy. Totals of 7 case-control and 11 cohort studies was identified and pooled ORs with 95% CIs were used as the principal outcome measures. Data from these studies were extracted with a standard meta-analysis procedure and grouped in relation to study design, cut-off point, exposure assessment method, adjustment and exposure model. A statistical significant increased risk of male breast cancer with EMF exposure was defined (pooled ORs = 1.32, 95% CI = 1.14-1.52, P < 0.001), and subgroup analyses also showed similar results. Conclusions: This meta-analysis suggests that EMF exposure may be associated with the increase risk of male breast cancer despite the arguments raised.