• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.35-42
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• 2015

This study was performed for both evaluating the safety of other processed products and providing basic information for making the general standard for contaminants in the category of other processed products. We analyzed the contents of three heavy metals, thirty six anti-impotence drugs and their analogues, three anti-obesity drugs and their analogues, twenty eight steroid drugs and their analogues, collecting in Incheon Metropolitan City. Any illegal compound was not detected in those products. However the contents of lead, cadmium and mercury of those products were at the range of 0.001-13.390 mg/kg, 0.03-1.231 mg/kg and 0.001-0.650 mg/kg respectively. Because there are no standards of heavy metals against other processed products, we compared the analytical results with relevant standards of both S. Korea and foreign countries. As a result, two products exceeded the relevant standards of lead, and other two products exceeded the relevant standards of mercury. The relative hazards compared to PTWI of FAO/WHO (Codex), Seafoods-pajeonmix, Perilla seed powder exceeded PTWI standards 0.214. The compulsory standards of each food product are determined by the category of the products. Because there is no standard of heavy metals in the category of other processed products in S. Korea, any food products registered as other processed product by manufacturer are free with those standards. Abusing similar problems on the categorization of food products could cause consumers' health problem. To prevent these problems, detail regulations on the categorization of food products have to be introduced.

• Journal of Science Education
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• v.34 no.2
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• pp.291-305
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• 2010

The aim of this study was to survey the perceptions of the elementary school teachers on the smallscale chemistry(SSC) following its training session. The teachers participating in the survey were 266 teachers in the Gyeongnam province. They were given a questionnaire that focused on the nine areas of the SSC: Needs for the teacher training and its application, its benefits, issues of safety and danger as well as treatment of environmental pollution, its economic efficiency and the development of investigative skills. The designed questionnaire was checked by an authority, and the responses to each question were tallied and analyzed. The results are as follows. The biggest problems of the traditional experimental methods as rated by the teachers were, in the order of importance, the preparation time, the legal liability of teachers for the safety and accidents, financial issues, disposal of the experimental wastes and the lack of relevant data. Since most of the teachers had not experienced the SSC lab programs in the field, they responded positively to the questions of need for its introduction and training. The implementation of the experimental SSC lab programs should proceed in the following order: introduction into the textbook, teacher training program, after-school education and the invitation of instructors. The most useful materials for the SSC program were CDs, videos, books and various printed materials, in that order. The responses regarding benefits of the SSC program included its simplicity, convenience, time savings, diversity, qualitative and quantitative aspects, integration into the regular class and use of toys. In particular, the teachers mentioned the increased safety due to the small amount of experimental reagents needed and the durability of plastic instruments. The familarity from the use of everyday tools as well as easy access to and the low-cost of the instruments were other important benefits. The teachers in general rated the educational content of the program highly, but many also found it to be average. Some pointed out the lack of sufficient discussion due to the individual or pair groupings as a potential shortcoming. The potential for development of problem solving ability and improvement of skills was rated positively. The number of teacher who rated the development of creativity positively was just over the half. As for the area of improving investigative skills, many found its assessment difficult and confusing because of the lack of its systemic definition and categorization. Based on the findings of this study, I would like to recommend the application and a wider dissemination of the small-scale chemistry lab program into the elementary school science curriculum.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.4
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• pp.342-352
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• 2020

Objectives: The characteristics of research workers are different from those working in the manufacturing industry. Furthermore, the reagents used change according to the research due to the characteristics of the laboratory, and the amounts used vary. In addition, since the working time changes almost every day, it is difficult to adjust the time according to exposure standards. There are also difficulties in setting standards as in the manufacturing industry since laboratory environments and the types of experiments performed are all different. For these reasons, the measurement of the working environment of research workers is not realistically carried out within the legal framework, there is a concern that the accuracy of measurement results may be degraded, and there are difficulties in securing data. The exposure evaluation based on an eight-hour time-weighted average used for measuring the working environment to be studied in this study may not be appropriate, but it was judged and consequently applied as the most suitable method among the recognized test methods. Methods: The investigation of the use of chemical substances in the research laboratory, which is the subject of this study, was conducted in the order of carrying out work environment measurement, sample analysis, and result analysis. In the case of the use of chemical substances, after organizing the substances to be measured in the working environment, the research workers were asked to write down the status, frequency, and period of use. Work environment measurement and sample analysis were conducted by a recognized test method, and the results were compared with the exposure standards (TWA: time weighted average value) for chemical substances and physical factors. Results: For the substances subject to work environment measurement, the department of chemical engineering was the most exposed, followed by the department of chemistry. This can lead to exposure to a variety of chemicals in departmental laboratories that primarily deal with chemicals, including acetone, hydrogen peroxide, nitric acid, sodium hydroxide, and normal hexane. Hydrogen chloride was measured higher than the average level of domestic work environment measurements. This can suggest that researchers in research activities should also be managed within the work environment measurement system. As a result of a comparison between the professional science and technology service industry and the education service industry, which are the most similar business types to university research laboratories among the domestic work environment measurements provided by the Korea Safety and Health Agency, acetone, dichloromethane, hydrogen peroxide, sodium hydroxide, nitric acid, normal hexane, and hydrogen chloride are items that appear higher than the average level. This can also be expressed as a basis for supporting management within the work environment measurement system. Conclusions: In the case of research activity workers' work environment measurement and management, specific details can be presented as follows. When changing projects and research, work environment measurement is carried out, and work environment measurement targets and methods are determined by the measurement and analysis method determined by the Ministry of Employment and Labor. The measurement results and exposure standards apply exposure standards for chemical substances and physical factors by the Ministry of Employment and Labor. Implementation costs include safety management expenses and submission of improvement plans when exposure standards are exceeded. The results of this study were presented only for the measurement of the working environment among the minimum health management measures for research workers, but it is necessary to prepare a system to improve the level of safety and health.

• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.271-279
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• 2016

To evaluate exposure characteristics of the insecticide imidacloprid to apple orchard workers during treatment on orchard fields and evaluate its potential risk using a whole body dosimetry (WBD) method, 1,000-time diluted acephate+imidacloprid 25(20+5)% solutions were sprayed on 10 apple orchard fields in Cheongju with a speed sprayer at a rate of 3,000 L/ha/person, after put on clothes such as inner/outer clothes, personal air pump with a IOM sampler, nitrile glove and mask. Exposure test included mixing, loading and application steps. The test pesticide imidacloprid residues in the collected samples were analyzed with a HPLC-DAD. Recoveries ranged from 81.5 to 108.6% for analytical method validation and from 73.8 to 86.7% for field recovery. Total exposed amounts to mixer/loader and applicator were found to be 0.0014-0.0279% of total applied active ingredient of imidacloprid. Glove exposure of both mixer/loader and applicator was higher than the other parts. Margins of safety of mixer/loader and applicator were calculated to be 97-355 and 46-196, respectively, indicating that exposure risk of imidacloprid to apple orchard workers by spraying with a speed sprayer was very low.

• Journal of Food Hygiene and Safety
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• v.35 no.3
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• pp.243-251
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• 2020

In this study, we investigated pesticide residues in 207 agricultural products distributed by direct trade in the northern area of Gyeonggi Province. A total of 94 general agricultural products and 113 eco-friendly agricultural products collected from local grocers and cooperative stores were analyzed by multiresidue method for 263 pesticides using GC (gas chromatography)/ECD (electron capture detector), GC/NPD (nitrogen phosphorus detector), GC-MS/MS (tandem mass spectrometry), LC (liquid chromatography)/PDA (photodiode array detector), LC/FLD (fluorescence detector), LC-MS/MS. All samples showing pesticide residues were general agricultural products collected from local food stores. The pesticide residue levels of 14 samples (6.8%) were below the maximum residue limits (MRLs) and one of them (0.5%) exceeded the MRLs. Sixteen pesticides were detected from samples of the following produce items: spinach, young cabbage, perilla leaves, mallow, cucumber, chives and water dropwort. The safety of the detected pesticides was assessed by monitoring the daily intake estimate (EDI) and the daily intake allowance (ADI) based on the amount of pesticides detected. The ADI percentage range (the ratio of EDI to ADI) was 0.0134-61.6259% and there was no health risk connected with consuming agricultural products in which pesticide residues were detected.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.11-21
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• 2019

The purpose of this study is to evaluate the awareness and usability of descending life lines and simple descending life lines for fire situations in the accommodation of the public officials who are responsible for supervising the installation and maintenance of descending life lines and simple descending life lines. The main results of the study are summarized as follows. First, in comparison of the ability to distinguish between descending life lines and simple descending life lines, the majority of female public officers in general administrative services do not have the ability to distinguish between descending lifelines and simple descending life lines, so they should be able to improve their ability to distinguish descending life lines. Also, institutional strategies are needed to regularly receive education through the Safety Experience Center in order to prevent safety accidents such as falling in emergency situations. Second, as a result of verifying reusability of simple descending life lines by gender and occupation, most public officers with the exception of half of the firefighting officers were analyzed as having no ability to reuse the simple descending life lines. Therefore, it is necessary to change the relevant laws so that only the installation of descending life lines which can be used continuously is permitted, except for the simple descending life lines among the evacuation instruments to be additionally installed in each room of the accommodation. Third, in terms of the ability to perceive the maximum load of the descending life lines according to occupation, the perception ability of the rescuers was the highest and the perception ability of the fire service personnel was the lowest. In order to improve the perception abilities of the fire service personnel, it is necessary to strengthen the theoretical and practical education of descending life lines in collective education such as the command-enhancing training which is regularly carried out in fire service academy. Lastly, it is believed that it is more effective to conduct the experience training of the descending life lines by imagining the fire in accomodations rather than other facilities, because it is the location where fires are actually seen the most.

• Proceedings of the Korean Geotechical Society Conference
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• 1991.10a
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• pp.87-102
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• 1991

It has been reported that the failure of Carsington Dam in Eng1and occured due to the existence of a thin yellow clay layer which was not identified during the design work, and due to pre-existing shears of the clay layer. The slope stability analyses during the design work, which utilized traditional circular arc type failure method and neglected the existence of the clay layer, showed a safety factor of 1.4. However, the post-failure analyses which utilized translational failure mode considering the clay layer and the pre-existing shear deformation revealed the reduction of safety factor to unity. The post-failure analysis assumed 10。 inclination of the horizontal forces onto each slice based on the results of finite element analyses. In this paper, Bishop's simplified method, Janbu method, and Morgenstern-Price method were used for the comparison of both circular and translational failure analysis methods. The effects of the pre-existing shears and subsquent movement were also considered by varying the soil strength parameters and the pore pressure ratio according to the given soi1 parameters. The results showed factor of safefy 1.387 by Bishop's simplified method(STABL) which assumed circular arc failure surface and disregarding yellow clay layer and pre-failure material properties. Also the results showed factor of safety 1.093 by Janbu method(STABL) and 0.969 by Morgenstern-Price method(MALE) which assumed wedge failure surface and considerd yellow clay layer using post failure material properties. In addition, dam behavior was simulated by Cam-Clay model FEM program. The effects of pore pressure changes with loading and consolidation, and strength reduction near or at failure were also considered based on properly assumed stress-strain relationship and pore pressure characteristics. The results showed that the failure was initiated at the yellow clay layer and propagated through other zones by showing that stress and displacement were concentrated at the yel1ow clay layer.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.94-101
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• 2015

To mitigate the greenhouse gas emission, many carbon capture and storage projects are underway all over the world. In Korea, many studies focus on the storage of $CO_2$ in the offshore sediment. Assurance of safety is one of the most important issues in the geological storage of $CO_2$. Especially, the assessment of possibility of leakage and amount of leaked $CO_2$ is very crucial to analyze the safety of marine geological storage of $CO_2$. In this study, the leakage of injected $CO_2$ through fault was numerically studied. TOUGH2-MP ECO2N was used to simulate the subsurface behavior of injected $CO_2$. The storage site was 150 m thick saline aquifer located 825 m under the continental shelf. It was assumed that $CO_2$ leak was happened through the fault located 1,000 m away from the injection well. The injected $CO_2$ could migrate through the aquifer by both pressure difference driven by injection and buoyancy force. The enough pressure differences made it possible the $CO_2$ to migrate to the bottom of the fault. The $CO_2$ could be leaked to seabed through the fault due to the buoyancy force. Prior to leakage of the injected $CO_2$, the formation water leaked to seabed. When $CO_2$ reached the seabed, leakage of formation water stopped but the same amount of sea water starts to flow into the underground as the amount of leaked $CO_2$. To analyze the effect of injection rate on the leakage behavior, the injection rate of $CO_2$ was varied as 0.5, 0.75, and $1MtCO_2/year$. The starting times of leakage at 1, 0.75 and $0.5MtCO_2/year$ injection rates are 11.3, 15.6 and 23.2 years after the injection, respectively. The leakage of $CO_2$ to the seabed continued for a period time after the end of $CO_2$ injection. The ratios of total leaked $CO_2$ to total injected $CO_2$ at 1, 0.75 and $0.5MtCO_2/year$ injection rates are 19.5%, 11.5% and 2.8%, respectively.

• Journal of Food Hygiene and Safety
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• v.39 no.3
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• pp.239-249
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• 2024

In this study, we investigated the concentrations of pesticide residues in agricultural products marketed in northern Seoul and assessed their potential health risks. A total of 1,737 samples were collected using the QuEChERS method, followed by LC-MS/MS and GC-MS/MS. Pesticide residues below the MRLs were detected in 560 samples of 72 items (32.2%), but 38 samples of 22 items had pesticide residues above the MRLs. Residual pesticides were detected in 53.8% of fruits, 33.0% of vegetables, 28.6% of herbs, 15.4% of beans, and 10.5% of rice samples. Most of the samples that exceeded the MRLs were vegetables, especially leafy, stalk, stem, and root vegetables; herbs and mushrooms also exceeded the permitted MRLs. Of the 105 pesticides investigated, dinotefuran, fluxametamide, chlorfenapyr, azoxystrobin, and carbendazim were the most frequently detected, whereas 23 pesticide residues, including terbufos, carbendazim, and fluxametamide, were detected above the MRL values. The hazard indices were calculated as 0.00003-1.31406%, which suggests that the investigated pesticide residues in the samples were within safe levels, but continuous monitoring of pesticides in agricultural products is needed to ensure the safety of consumers.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.468-476
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• 2020

We aimed to analyze the microbiological quality of the ready-to-eat (RTE) side dishes collected from traditional markets, supermarkets, and cafeterias in Gyeonggi-do in 2019. A total of 108 samples were analyzed for total aerobic bacterial counts, coliforms and foodborne pathogens depending on place of purchase and cooking methods. Results show that Bacillus cereus was detected in 14 (12.9%) out of 108 samples of side dishes, while no other foodborne pathogens were detected. The mean detected level (range) of total aerobic bacteria depending on place of purchase was 5.8 log CFU/g (3.0 to 8.2 log CFU/g) for traditional markets, 4.3 log CFU/g (2.4 to 7.8 log CFU/g) for supermarkets, and 3.80 log CFU/g (0.0 to 6.8 log CFU/g) for cafeterias, indicating that there was a significant (P<0.05) difference in total aerobic bacterial counts among places of purchase. Among the samples, the highest counts of total aerobic bacteria and coliforms were detected in saengchae (raw vegetables), followed by namul (seasoned herbs, vegetables), bokkeum (stir-fried foods), and jorim (foods cooked in soy sauce). The growth of total aerobic bacteria in seasoned soybean sprouts was inhibited when the sprouts were stored at 4℃ up to 24 h, whereas bacteria rapidly grew at 20 and 35℃ after 3 and 6 h, respectively. These results reveal that storage temperature might play a significant role for the microbiological quality of seasoned soybean sprouts when they are sold in markets. Thus, this study suggests that RTE side dishes should be stored at refrigerated temperature when being sold at markets as well as after purchasing to improve their microbiological quality.