• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.12
• /
• pp.1779-1784
• /
• 2009

Establishment of simultaneous analysis method and monitoring for individually analyzing residual eight ergosterol biosynthesis inhibitors, EBI (difenoconazole, diniconazole, fenarimol, fenbuconazole, hexaconazole, myclobutanil, nuarimol and paclobutrazol) pesticides in commercial agricultural products, were conducted. The simultaneous analysis method for the pesticides was established using a GC/MS/MS for EBI pesticides. Residual amount of those pesticides were investigated in 989 commercial agricultural products (fifteen kinds of cereal grains, vegetables, beans, nuts, fruits and mushrooms) from seven metropolitan cities and eight provinces. In EBI pesticides analysis, linearity of GC/MS/MS analysis was 0.9974-0.9992, and that of recoveries were 86-135% with relative standard deviations (RSD) <20%. The limit of quantification (LOQ) of the method ranged from 0.5 to 5.0 mg/kg for eight EBI pesticides. According to the monitoring of the EBI pesticides in commercial agricultural products, difenoconazole, fenarimol, hexaconazole showed various residual levels (total frequency of 8/989 detection, 0.8%). Paclobutrazole showed in excess levels of the MRLs (maximum residue limits) for pesticides in one chard sample by the Korea Food Code. As a result of exposure assessment on the detected 8 individual pesticides, all pesticides (difenoconazole, fenarimol, hexaconazole, paclobutrazole) were evaluated as safe level in comparison to toxicologically acceptable daily intake.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2005.06a
• /
• pp.21-29
• /
• 2005

The HANARO, a multi-purpose research reactor of 30 MWth open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. Recently, ten years after the initial operation of the HANARO, one of the two primary cooling pumps was decontaminated for overhaul maintenance in 2004. Before decontamination exposure doserate and surface contamination level of primary cooling pump measured at 4 points. After final decontamination exposure doserate and surface contamination level of primary cooling pump remeasured by same method done before. It is easy to decontaminate the out side exposed surfaces of the pump, but it is difficult to approach the inside surface due to double volute installed in the casing. Therefore, a new decontamination facility has been developed to solve this problem. A concentrated de-contaminant (DX-300) is rotated in the closed pump casing by the impeller actuated by a temporary motor. Nuclide particles are removed by the emulsification effect of the de-contaminant and the surface contaminants are chemically removed from the pump by the corrosion and dissolution effect. The inside surfaces of the primary cooling pump have been decontaminated by using the facility. As results, the contamination level of the inside surfaces was maintained below the surface contamination limit.

• Analytical Science and Technology
• /
• v.27 no.5
• /
• pp.243-247
• /
• 2014

Formaldehyde is defined as carcinogen causing leukaemia, lymphoma or nasopharyngeal carcinoma at high level of exposure. Furniture-manufacturing workers can be exposed to formaldehyde, which implies serious impact on health of the workers. The authors carried out ambient monitoring of formaldehyde in the field, and identified the source of formaldehyde generated during the working process by testing the condition in the laboratory settings. After sampling formaldehyde in the air with 2,4-DNPH (2,4-dinitrophenylhydrazine) coated silica gel, we extracted formaldehyde derivative with acetonitrile and analyzed the extract using HPLC with UV detector at 360 nm. Formaldehyde was separated by ACQUITY UPLC BEH $C_{18}$ column at a flow rate of 0.5 mL/min using 45% acetonitrile as mobile phase. The workers were exposed to higher level of formaldehyde than normal air. Formaldehyde up to 0.31 ppm was detected in the process of veneer attachment, which exceeded 0.3 ppm, the ceiling value of ACGIH standard. The laboratory test of measuring formaldehyde generated from the glue and veneer used in the attachment process resulted in more formaldehyde generation as the temperature increased, and more from the veneer. Heating the veneer to $100-150^{\circ}C$ following the real condition of the manufacturing site generated 1.14-2.70 ppm of formaldehyde from the sample, which was 2-5 times higher level than Korean limit of exposure (0.5 ppm). As the workers handling and processing the veneer which was produced by wet process had high possibility to be exposed to formaldehyde, urgent improvement and management of working environment of furniture manufacturer is demanded.

• Journal of Energy Engineering
• /
• v.29 no.1
• /
• pp.63-74
• /
• 2020

The Kori-Unit 1 nuclear power plant, which is scheduled for decommissioning after permanent shutdown, is expected to generate a large amount of various types of radioactive waste during decommissioning process. For concrete radioactive waste, which is expected to occupy the most amount, it is important to analyze the current waste disposal status and legal limitations and to prepare an appropriate and efficient disposal method. Concrete radioactive waste is waste of various levels, of which the clearance level is bioshield concrete. In this paper, clearance radioactive waste safety evaluation was performed using the RESRAD code, which is a safety evaluation code, based on the activation evaluation results for the wastes with the clearance level. The clearance scenario of the target radioactive waste was selected and the individual's exposure dose was calculated at the time of clearance to determine whether the clearance criteria limit prescribed by the Nuclear Safety Act was satisfied. As a result of the evaluation, the results showed significantly lower results and satisfied the criteria value. Based on the results of this clearance safety assessment, the appropriate disposal method for bioshield concrete, which are the clearance wastes of subject of deregulation, was suggested.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.11 no.3
• /
• pp.219-228
• /
• 2001

Objective : For the purpose of preparing the fundamental data and health promotion and control program on organic solvents in air of manufacturing industry. Methods : The author surveyed number of organic solvent components which was used in working site and also determined the organic solvents concentration in air of 927 manufacturing industries and 1,267 working process with gas chromatography(NIOSH manual) for five years from 1995 to 1999. Results : Mean number of solvents components by type of industry, working process was number of 12. There were exceeded to TLV of 1,2-dichloroethane in textile manufacturing industry N,N-dimethyl furan in tanning and dressing of leather ; luggage, handbags, saddlery, harness and footwear manufacturing industry and chemical and chemical product manufacturing industry by type of industry. There were exceeded to TLV of 1,2-dichloroethane in handwriting and drawing process, cellosolve in adhesive spreading process, N,N-dimethly furan in production of solvent process and adhesion process by working process Total exceeded rate to threshold limit values of organic solvents mixture were 12.9% for EI(Exposure index) and 10.0% for Em(Estimation of mixture) by type of industry, 11.3% for EI and 8.2% for Em by type of working process. The highest exceed rate was 36.7% for EI in tanning and dressing of leather ; luggage handbags, saddlery, harness and footwear manufacturing industry and 29.0% for Em in textile manufacturing industry. The highest exceeded rate was 23.1% for EI and 12.5% for Em in adhesive spreading process by working process. Mean values of total subjects by type of industry and type of working process were $0.7{\pm}1.8$ for EI and $0.7{\pm}1.7$ for Em respectively. Conclusions : As above results, the author suggest that it makes the environmental control program on 1.2-dichloroethane, N,N-dimethyl furan, cellosolve by kind of organic solvent and on textile manufacturing industry, tanning and dressing of leather ; luggage, handbags, saddlery harness and footwear manufacturing industry by type of industry, and on handwriting, drawing process and adhesive spreading process and adhesion process by type of working process.

• Korean Journal of Food Science and Technology
• /
• v.34 no.6
• /
• pp.969-976
• /
• 2002

The migrating level of di-(2-ethylhexyl) adipate (DEHA) in PVC wrap to various foodstuffs dishes was determined using acetone/n-hexane as an extracting solvent. The recovery ratio of DEHA from various foodstuffs ranged from 81.3 to 91.2%. During storage at $10\;or\;20^{\circ}C$ for up to 3 days, highest migration of 22.9 mg/kg occurred with pork belly, an indication that increases in fat content, storage temperature, and storage time result in increasing DEHA migration. DEHA concentrations of various delivered dishes ranged between 6.9 and 29.8 mg/kg, and highest migration was observed in Chambbong, which had the highest fat content among samples. After microwave-reheating, which resulted in a tight contact between film and food samples, DEHA was not detected in rice and potato, whereas up to 158.8 mg/kg was detected in pizza. When the wrap film was not contacted with the surface of food, the migration was lowered. Migration levels of DEHA from PVC wrap film into samples under various exposure conditions often exceeded the limit value of $3\;mg/dm^2\;and/or\;18\;mg/kg$ set by the European Union.

• Journal of Science and Technology Studies
• /
• v.19 no.3
• /
• pp.119-166
• /
• 2019

The risk of electromagnetic field(EMF) from power lines has been heavily disputed whenever high-voltage power line towers were built in South Korea. Local communities and civic groups had regarded burying the lines in the ground as an alternative to building power line towers. In 2014, however, when an elementary school science teacher reported the results of EMF measurements over the underground power lines to the Asian Citizens' Center for Environment and Health (ACCEH), the risk controversy over underground power lines took a whole new turn. The level of EMF from underground power lines turned out to be higher, and therefore more harmful than that from power line towers. In the debates that took place from then on over the EMF risk, ACCEH and NIER(National Institute of Environmental Research) presented conflicting topographies of EMF risk. This paper examines measuring practices of ACCEH and NIER by analyzing the measuring sites, measuring devices, and measuring heights chosen by each organization. This paper further examines how ACCEH and NIER mobilized various standards(EMF exposure limit, measurement guideline, categorization of carcinogens) differently. This controversy on the EMF from underground power lines of Seoul has raised concerns on the non-thermal effects of EMF in the long-term exposure and has led people to question whether burying the power lines is the safe alternative to building power line towers. Furthermore, this suggests conflicting answers on whether Seoul, where 90 % of transmission lines were already buried, is a safely managed place or not.

• Korean Journal of Radiology
• /
• v.19 no.6
• /
• pp.1179-1186
• /
• 2018

Objective: The purposes of this study were to evaluate size-specific dose estimate (SSDE) of low-dose CT (LDCT) in the Korean Lung Cancer Screening (K-LUCAS) project and to determine whether CT protocols from Western countries are appropriate for lung cancer screening in Korea. Materials and Methods: For participants (n = 256, four institutions) of K-LUCAS pilot study, volume CT dose index ($CTDI_{vol}$) using a 32-cm diameter reference phantom was compared with SSDE, which was recalculated from $CTDI_{vol}$ using size-dependent conversion factor (f-size) based on the body size, as described in the American Association of Physicists in Medicine Report 204. This comparison was subsequently assessed by body mass index (BMI) levels (underweight/normal vs. overweight/obese), and automatic exposure control (AEC) adaptation (yes/no). Results: Size-specific dose estimate was higher than $CTDI_{vol}$ ($2.22{\pm}0.75mGy$ vs. $1.67{\pm}0.60mGy$, p < 0.001), since the f-size was larger than 1.0 for all participants. The ratio of SSDE to $CTDI_{vol}$ was higher in lower BMI groups; 1.26, 1.37, 1.43, and 1.53 in the obese (n = 103), overweight (n = 70), normal (n = 75), and underweight (n = 4), respectively. The ratio of SSDE to $CTDI_{vol}$ was greater in standard-sized participants than in large-sized participants independent of AEC adaptation; with AEC, SSDE/$CTDI_{vol}$ in large- vs. standard-sized participants: $1.30{\pm}0.08$ vs. $1.44{\pm}0.08$ (p < 0.001) and without AEC, $1.32{\pm}0.08$ vs. $1.42{\pm}0.06$ (p < 0.001). Conclusion: Volume CT dose index based on a reference phantom underestimates radiation exposure of LDCT in standard-sized Korean participants. The optimal radiation dose limit needs to be verified for standard-sized Korean participants.

• Journal of Environmental Health Sciences
• /
• v.49 no.4
• /
• pp.218-227
• /
• 2023

Background: Since 2019, the Ministry of Environment has implemented a seasonal fine dust management system from December to March, targeting high PM_2.5 levels with the aim of reducing PM_2.5 concentrations and protecting public health. The focus of improving the seasonal management system lies in the atmospheric PM_2.5 levels. Considering the primary goal of protecting public health, it is necessary to analyze the policy effects from an exposure perspective rather than a concentration-based approach. Objectives: This study aims to quantitatively assess the improvement of indoor PM_2.5 levels and the health impacts of the seasonal management system by comparing the periods before and during its implementation in residential environments. Methods: PM_2.5 concentrations within residential environments in a metropolitan area were measured using an optical particle counter (IAQ-C7, K-weather, Ltd, Korea) at one-minute intervals during the pre-implementation period (November 21~25, 2022) and during the implementation period (December 19~23, 2022). Based on the measured PM_2.5 concentrations, a quantitative evaluation of cancer and mortality risks was conducted according to age and gender. Results: The results of comparing indoor and outdoor PM_2.5 concentrations before and during the implementation of the seasonal management system showed a decrease of approximately 56.6% and 47.9%, respectively. Health risk assessments revealed that both the safety-limit-based and safety-target-based Hazard Quotients (HQ) exceeded the threshold of 0.1 for children under 19 years of age, both before and after the implementation. The mortality risk decreased by approximately 47.9% after the implementation, with children aged 0-9 showing the highest mortality risk at 0.9%. Conclusions: The findings of this study confirmed the positive health impacts of the seasonal management system across all age groups, particularly children under 19 who are more vulnerable to fine dust exposure.

• Fisheries and Aquatic Sciences
• /
• v.25 no.12
• /
• pp.626-636
• /
• 2022

Shellfish are exoskeleton-bearing aquatic invertebrates that consume various organic and inorganic substances floating in seawater through filter feeding. Heavy metals are known as absorbed and accumulated in seawater. Some of the toxic heavy metals are highly accumulated in seawater, and exposure to them can cause a variety of risks to the human body. Since Koreans like to eat seafood, they are more likely to be exposed to contaminated seafood with heavy metals. In this study, nine types of heavy metals were analyzed on ten different shellfish species in the coastal area of South Korea. The risk assessment was also done on shellfish in which heavy metals were detected. Zinc (Zn) and copper (Cu) were identified at an average of 56.7 mg/kg (6.70 to 466 mg/kg) and 13.2 mg/kg (0.064 to 143 mg/kg), respectively. Lead (Pb) average of 0.208 mg/kg (0.000750 to 1.02 mg/kg), cadmium (Cd) average of 0.454 mg/kg (0.0388 to 1.56 mg/kg) and mercury (Hg) average of 0.0266 mg/kg (0.00548 to 0.174 mg/kg) were identified. Additionally, arsenic (As), chromium (Cr), nickel (Ni), and silver (Ag) were also identified as average concentrations of 4.02 (0.460 to 15.0 mg/kg), 0.167 (< limit of quantification [LOQ] to 0.820 mg/kg), 0.281 (< LOQ to 1.46 mg/kg), and 0.158 mg/kg (< LOQ to 1.15 mg/kg). The result indicates that the monitoring results of heavy metals in most shellfish satisfied the Korean standard. However, Pb and Cd have exceeded some foreign standards, such as the United States and the EU. The permissible human exposure calculated using the heavy metal intake and detection amount was lower than the Joint FAO/WHO Expert Committee on Food Additives human safety standard, and the risk of heavy metals from shellfish consumption was at an acceptable level.