• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.99-108
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• 2002

This study was carried out to evaluate the Physicochemical characteristics of mined waste(separated waste and soil) and to predict environmental effect of an old landfill site located at north of Seoul. Municipal solid waster(MSW) had been disposed of at the old landfill site used in this study for about 2 years(1990-1992). The old landfill site selected for this study had accepted mainly municipal solid waste. The landfill-mined waste contained separated waste (40.9%) and soil(59.1%) by wet weight basis. The separated waste consisted of combustible(91.0%) and non-combustible(9.0%). The combustible waste was mainly non-biodegradable plastics. The low heating value of the separated combustible waste, which is calculated by Dulong's equation, was as high as 3,470kcal/kg. According to the Korean Extraction Procedure, separated waste and soil were proved to be not hazardous. The total content of heavy metal in the separated waste and soil met standard of California State, USA. Therefore the separated waste may be relandfilled at a sanitary landfill site and/or burned up at an incinerator, and the separated old soil may be used ad landfill cover-soil at a sanitary landfill site. Water quality of two streams was grade IV, of which water could be used as industrial and agricultural water. The streams near the landfill site might not be contaminated by leachate from the old landfill site. It was estimated that organic matter in the old landfill site would not be actively biodegraded within a short period of time.

• Journal of Environmental Health Sciences
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• v.35 no.2
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• pp.78-85
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• 2009

In this study, the hazard rate of the indoor environment of Children's Educational Facilities in Seoul was conducted, in order to determine how the indoor environments of these facilities, where infants and children spend the most time of their away from home day, can effect their health. The way of measurement and analysis were done according to the Indoor Air Quality Standard Method, and the Risk Assessment was accomplished with several significant ways - Hazard Identification, Exposure Assessment, Dose-response Assessment, Risk Characterization, which are deighed by National Research Council (NRC). On each exposure factors, documentary and questionary research such as Epidemiological study and Toxicological study were conducted. The result of the CTE (Central tendency exposure) of Formaldehyde and Benzene by Monte-Carlo simulation was $6.79{\times}10^{-6}$, $2.50{\times}10^{-7}$ which in the case of Formaldehyde exceeded the permitted standard ($10^{-6}$) of the US EPA. The RME(Reasonable maximum exposure) was $7.31{\times}10^{-5}$, $2.65{\times}10^{-6}$ which did not exceed $10^{-4}$, the maximum permitted standards in the US EPA.

• Journal of Environmental Health Sciences
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• v.47 no.2
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• pp.166-174
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• 2021

Objectives: This study aimed to provide temporal Acute Exposure Guideline Levels (AEGL) for a hazardous substance as a pilot study. Methods: As one of the substances designated by the Korea Ministry of Environment as requiring preparations for potential accidents, formaldehyde was selected to estimate the AEGLs. The calculation was based on Haber's formula (Cn×t=k) using valid toxicity data (for humans/animals). A total of 96 points of AEGL levels were provided using an interval of five minutes over eight hours. Results: The AEGL-1 and 2 values were constant for the entire exposure duration at 0.9 ppm and 14 ppm, respectively. The values were obtained from clinical/animal tests, and the adaptation effect after a given exposure duration was also considered. AEGL-3 was based on animal toxicity data, and it was estimated from 127 ppm for the initial five minutes to 35 ppm for eight hours. Conclusions: More specific AEGL levels for formaldehyde could be obtained in this study using toxicity data with Haber's formula. Based on this methodology, it would be also possible to estimate AEGL levels that can be used at the scene of a chemical accident for other substances requiring preparation for potential accidents.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.3
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• pp.300-306
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• 2009

Welding technology is applicable in many kinds of fields, with the help of its advantages such as easy operational procedure and structural simplification. However, in the process of welding, hazardous materials and fumes cause huge fire broke-outs, explosions, and health-conscious problems. Also, as heavy metals in fumes have a harmful effect on the environment, recently, this has emerged as a urgent social issue. This study has been aimed at the recommendation of the most environment-friendly, among materials currently used in plumbing welding, and it has been done at the result of the analysis of amount, ingredient, and size in collected fumes created in the experiment of welding five rods to galvanized steel pipes and steel pipe ones. At the test result, due to the effect of Zn-coating, galvanized steel pipes, when welded to rods, created more fumes than steel pipe ones. In the mean time, when it comes to welding rods, among five, WR-03 produced fumes the least. Therefore, a combination of the test results clearly indicates that the case of welding WR-03 to cast-iron pipes turned out to be the most environment-friendly.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.1
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• pp.27-34
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• 2013

Objectives: The purpose of this study is to calculate the worker-DNEL (Derived No Effect Level) values using the REACH guidance and compare the calculated DNELs with existing Korea occupational exposure limits (KOELs) for evaluation of the applicability of the worker-DNELs as provisional occupational exposure limits for chemicals that are not established KOELs in the workplace. Methods: The worker-DNELs for 46 chemicals among 113 hazardous substance requiring management were calculated using the REACH guidance, and a paired t-test was performed to see if there is any statistical difference between two lists (worker-DNELs vs KOELs). The ratios of KOELs over worker-DNELs were also calculated to compare the overall levels of two lists using the geometric means method. Results: The calculated worker-DNELs for 46 chemicals ranged from 0.001 to $329mg/m^3$ (GM= 6.9, GSD = 10.8), and appeared to be a significant difference between the worker-DNELs and the KOELs (p < 0.01). In addition, the ratios of KOELs over worker-DNELs ranged from 0.3 to 394 times (GM = 10.2, GSD = 3.9), indicating that the worker-DNELs were, on average, 27 times lower than the KOELs. Conclusions: Therefore, the study results show that the calculated worker-DNELs can be applied and used as provisional occupational exposure limits in the workplace in order to reduce worker exposures to chemicals and health risks, and manage potential worker exposures based on the precautionary principle through comprehensive chemical risk assessment.

• Journal of Environmental Health Sciences
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• v.37 no.2
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• pp.113-123
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• 2011

Objectives: Industrial development in Korea results in a rapid increase in the number of chemicals, some of which may be responsible for toxicity to aquatic ecosystems. In addition, the types of hazardous chemicals included in industrial effluents have gradually increased. Therefore, chemical analysis alone is not enough to assess ecological effects of toxic chemicals in wastewater. Methods: In response to new regulations as whole effluent toxicity (WET) tests for effluent discharge of 15 publicly owned treatment works (POTWs) and 25 industrial effluent treatment plants in Gyeonggi-do, which will be effective from 2011, a necessity of studies emerges that investigates toxicity levels. Results: In case of the public treatment plants, none of them had exceeded the criteria for ecotoxicity. As for individual wastewater discharge facilities, on the other hand, two types were found to exceed the criteria: pulp and paper manufacturing facilities and pharmaceutical manufacturing facilities. For the pulp and paper manufacturing facilities, monitoring results could not help determine the exact toxicant identification. However, Daphnia magna inhibition effect or death was found to leave white plums, suggesting that suspended solids treated and the polymer used in coagulant dose. In case of pharmaceutical manufacturing facilities, the general water quality parameters cannot affect Daphia magna. However, conductivity and salinity can have an effect to be 14,000 ${\mu}s/cm$, 8.1‰ by salts, respectively. Toxicity Identification Evaluation (TIE) and Toxicity Reduction Evaluation (TRE) procedures results appeared to be effective for identifying toxic compounds in $Cl^{-}$ and $SO_4^{2-}$. Conclusions: It is necessary to develop control measures for water treatment chemicals and salts used for processes such as coagulation in individual wastewater discharge facilities in order to achieve the goal to protect aquatic ecosystems in public waters.

• Safety and Health at Work
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• v.4 no.2
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• pp.105-110
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• 2013

Background: To determine the influence of lifting speed and type on peak and cumulative back compressive force (BCF) and shoulder moment (SM) loads during symmetric lifting. Another aim of the study was to compare static and dynamic lifting models. Methods: Ten male participants performed a floor-to-shoulder, floor-to-waist, and waist-to-shoulder lift at three different speeds [slow (0.34 m/s), medium (0.44 m/s), and fast (0.64 m/s)], and with two different loads [light (2.25 kg) and heavy (9 kg)]. Two-dimensional kinematics and kinetics were determined. A three-way repeated measures analysis of variance was used to calculate peak and cumulative loading of BCF and SM for light and heavy loads. Results: Peak BCF was significantly different between slow and fast lifting speeds (p < 0.001), with a mean difference of 20% between fast and slow lifts. The cumulative loading of BCF and SM was significantly different between fast and slow lifting speeds (p < 0.001), with mean differences ${\geq}80%$. Conclusion: Based on peak values, BCF is highest for fast speeds, but the BCF cumulative loading is highest for slow speeds, with the largest difference between fast and slow lifts. This may imply that a slow lifting speed is at least as hazardous as a fast lifting speed. It is important to consider the duration of lift when determining risks for back and shoulder injuries due to lifting and that peak values alone are likely not sufficient.

• Journal of Environmental Health Sciences
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• v.49 no.6
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• pp.334-343
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• 2023

Background: South Korea's Act on Registration and Evaluation, etc. of Chemicals (known as K-REACH) was established to protect public health and the environment from hazardous chemicals. 4,4'-Methylenedianiline (MDA), which is used as a major intermediate in industrial polymer production and as a vulcanizing agent in South Korea, is classified as a toxic substance under the K-REACH act. Although MDA poses potential ecological risks due to industrial emissions and hazards to aquatic ecosystems, no ecological risk assessment has been conducted. Objectives: The aim of this study is to assess the ecological risk of MDA by identifying the actual exposure status based on the K-REACH act. Methods: Various toxicity data were collected to establish predicted no effect concentrations (PNECs) for water, sediment, and soil. Using the SimpleBox Korea v2.0 model with domestic release statistical data and EU emission factors, predicted environmental concentrations (PECs) were derived for ten sites, each referring to an MDA-using company. Hazard quotient (HQ) was calculated by ratio of the PECs and PNECs to characterize the ecological risk posed by MDA. To validate the results of modeling-based assessment, concentration of MDA was measured using in-site freshwater samples (two to three samples per site). Results: PNECs for water, sediment, and soil were 0.000525 mg/L, 4.36 mg/kg dw, and 0.1 mg/kg dw, respectively. HQ for surface water and sediment at several company sites exceeded 1 due to modeling data showing markedly high PEC in each environmental compartment. However, in the results of validation using in-site surface water samples, MDA was not detected. Conclusions: Through an ecological risk assessment conducted in accordance with the K-REACH act, the risk level of MDA emitted into the environmental compartments in South Korea was found to be low.

• Korean Journal of Health Education and Promotion
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• v.19 no.2
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• pp.57-72
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• 2002

Students spend most of their time in school. Schools have the possibility of unanticipated accidents, however, and the rate of accidents in schools is increasing. The purpose of this study were to understand the accidents that arise in schools as well as the school safety management system and by analyzing affects that school safety management system has on accidents in schools, to come lip with a preventive plan. 906 high school sophomore students attending in Seoul were surveyed 1Tom November 12th to 23rd 2001. The results were following: 1. Students surveyed comprised of the following: Male 48.9%, Female 51.1% Public Schools 32.6%, Private Schools 67.4% Boys Schools 48.9%, Girls Schools 51.1% 2. In the past year, male students had more accidents(p〈.05) in school. 3. In examining students safety management control, 94.0% said that, there is an infirmary, there is a clear distinction between the playing fields and pathways(74.8%), and the chemicals in the labs are kept in a safe manner(77.2%). The above items were generally well maintained. However, the following recorded low scores. There are warning signs in hazardous places and facilities(30.5%), There is guiding principle to examine the safeness on a regular basis(24.9%), and There are slogans and posters preventing accidents(40.3%). 4. In examining the facilities of the schools that were surveyed, the majority answered, yes to the following. There are hazardous facilities or materials at school(62.9%), There are sharp edges in educational supplies and equipment(59.8%), There are nails or other components that are sticking out of desks and chairs(75.9%), There are slippery spots in the corridors and classrooms(69.3%), There are stones, scrap metal, broken glass, and trash on the playing fields(66.6%). Furthermore, the students surveyed said, yes to the following although in low percentages. The amount of sand on the playing fields is sufficient(49.1%), The soccer and basket goal posts are fastened (53.7%), There are safety bars on the windows of classrooms and corridors (27.4%), There are safety mats on the entrance to restrooms preventing slips (14.2%), The stairs have slip protection measures(49.1%). 5. In analyzing the affect that the school safety management system has on accidents in school, schools that had slogans and posters preventing accidents had a 50% less chance of accidents(p〈.05), schools with chemicals and equipment in the labs that were safely maintained had an 80% less probability of accidents(p〈.0l), and the schools that had sharp edges in the educational supplies and equipment had an 80% greater chance of accidents(p〈.01).

• Journal of the Korean Society of Safety
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• v.28 no.2
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• pp.14-20
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• 2013

All most of floors can become less slip resistant with wear. The deterioration of slip resistance can often occur rapidly. So relatively new products can become hazardous within a short period of time. The main objective of this study was the comparison of slip resistance variations caused by traffic wear and accelerative wear. The second objective was to ascertain the effect of wear, and to find out the causes of slip resistance change. Although statistical differences were observed between results of traffic wear and accelerative wear, the trend of the variations of slip resistance caused by traffic wear and accelerative wear was very similar. The measured slip resistance of tested floor changed up to 29%(and 26.5%) after 100,000 steps(and 750 cycles). As the traffic wear and accelerative wear were progressed, the surface roughness of the tested floor became smoother, and so the floor became more slippery under the wet condition. The abraded(worn out) floor surface tended to become hydrophilic surface, while the new floor surface tended to show hydrophobic nature. This phenomenon would change the wettability of floor surface, and the wettability would affect the variation of slip resistance.