• Journal of Korean Society of Environmental Engineers
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• v.36 no.2
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• pp.127-138
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• 2014

As increasing concerns about potential risks and hazards in children's products, the laws and regulations for heavy metals and phthalate retardants contained in the children's products have been reinforced in many countries. Especially, in Korea, environment and health laws and regulations for children's products was declared in 2009. This study was researched in terms of contents and migration of phthalates and heavy metals in 124 children's products sold in the Korean market. The results for contents of heavy metals showed that 123 products contained different 14 heavy metals depending on kinds of products. As the results of migration by sucking, the heavy metals in the products such as black, plastic dolls, wood toys, and bottom mat for swimming were transferred into extraction solution. Ba, Cu, Zn, and Sn were transferred from most of these products into the extraction solution and Co, Ni and Pb were additionally transferred into several products. As the results of migration through a skin, while Ba, Cu, and Zn were transferred from most products containing the heavy metals, as for accessories, Cr, Ba, Ni, Zn, and Cu were migrated. The results of contents of phthalates presented that 21 products contained DBP, DEHP and DINP. Only 2 products showed the migration of DEHP by sucking. DEHP in most products were transferred and DBP for 2 products and DINP for 7 products were migrated.

• Fire Science and Engineering
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• v.33 no.4
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• pp.140-151
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• 2019

It is to assess the indoor air quality of the chemical hazardous materials exposed to the fire after firefighters returned to the fire scene. The research subject randomly selected four fire stations located in Seoul, Korea. Two fire stations were set up as control groups after the return of the firefighting activities at the actual fire scene, and two other fire stations were set up as control groups to measure the air quality of the room at normal levels regardless of the action. We conducted 24-hour monitoring for all fire accidents that occurred in Seoul Metropolitan using fire safety map computer system. Also, indoor air quality was measured immediately after homecoming if the experiment group was to be dispatched due to an accident of intermediate or larger scale. 11 hazardous substance items such as fine dust, formaldehyde, volatile organic compounds, PAH, VCM, acidity, asbestos, CO₂, NO₂, O₃ were measured according to the process test method. Three of 11 types of harmful substances exceeded domestic and foreign standards, and one of them was found to be close to foreign standards. In particular, total volatile organic compounds, carbon dioxide and sulfuric acids were 2.5 times, 2.2 times and 1.1 times higher than the standard. Also, for formaldehyde and sulfuric acid, it was measured higher in the control group than in the case group. This findings could be used in policies to improve indoor air quality in the fire station of the Seoul Metropolitan Government.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.1
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• pp.13-21
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• 2021

Objectives: The purpose of this study was to evaluate the exposures of cashiers who work at expressway tollbooths. Methods: We measured temperature(temp.), relative humidity(RH), and contaminants with direct reading instruments at ten expressway toll gate in September 2015. Elemental carbon was collected on the quartz filters and analyzed with an OCEC analyzer. Results: The average levels for temp., RH, carbon monoxide, carbon dioxide, dust(PM10), and black carbon were respectively 24.6~27.8℃, 32.3~65.3%, 0.5~1.2 ppm, 456~559 ppm, 12~111 ㎍/㎥, and 3.1~10.1 ㎍/㎥ at each tollbooth. The concentrations of elemental carbon within the tollbooth(1.8~7.2 ㎍/㎥) were lower than outdoors(2.5~10.0 ㎍/㎥), but exhibited a high correlation(r2=0.855). The exposure levels for carbon monoxide, black carbon, and elemental carbon in the tollbooths were significantly higher than the offices. The concentrations of black carbon and elemental carbon showed a high correlation(r2=0.756). Conclusions: The levels of contaminants were below the occupational exposure limits in the expressway tollbooth. There were ventilation and air conditioning systems in the booths, but it is necessary to maintain and use the systems properly.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.505-508
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• 2008

Concrete is a type of porous materials and is physically and chemically damaged due to exposure to various environments from the placing to the service life. These reactions affect the corrosionof steel bars applied in concrete and that decreases the durability life and strength of such steel bars. Thus, it is very important to insert rust inhibitors into steel bars in the case of a deterioration element that exceeds the critical amount of corrosion in the location of steel bars. However, it is very difficult to guarantee corrosion resistance at the location of steel bars using conventional technology that applies corrosion inhibitors only on the surface of concrete. This study attempts to develop a method that penetrates corrosion inhibitors up to the location of steel bars and investigate the penetration depth of corrosion inhibitors by verifying moisture migration in concrete under an applied pressure.

• Analytical Science and Technology
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• v.25 no.1
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• pp.69-75
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• 2012

This study was performed to survey the school supplies such as pencil, eraser, notebook and color paper. Twenty-two kinds of samples were collected near the school zone, and eight kinds of phthalate which is one of the environmental hazard factors analyzed to estimate the contents characteristics of products. As the results of these research, three kinds of phthalates (BBP, DNOP and DIDP) were not detected in the selected samples. In the A group, DEHP and DINP were detected in the rage of 22%~28%, and DINP was selected 28%, 24% and 28% in the A-1, A-3 and A-4 samples, respectively. But the selected samples in the B group were detected less than 1,000 ppm as regulated level. Also, The DBP was detected 1% in the C-2 sample, and DEHP was detected 0.3% in the C-1 and C-6 samples. The DEHA was detected 0.3% in the D-3 sample. In this study, the DINP was mainly detected the eraser, therefore this kind of phthalate can be exposed through dermal exposure.

• Analytical Science and Technology
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• v.23 no.4
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• pp.357-362
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• 2010

Phthalate plasticizer is not human carcinogens which has been classified as environmentally hazardous substance. Phthalates are absorbed into the body and cause tumors and ecological mutation to human potentially as reproductive toxic substances. For this reason, in some countries the use of phthalates in products for children has been banned. In this study, we proposed the analytical method of phthalate content and migration rate for children's product which was compared and reviewed to the analytical method of various countries, United States, Japan, European Union. The children's product on the proposed analytical method was analysed to consider of the correlation between the phthalate content and migration rate, but there was no correlation both of them.

• Journal of Environmental Science International
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• v.24 no.5
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• pp.699-708
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• 2015

This study was performed to identify the state of the exposure and characteristics of pollutants by each process at 4 casting sites located in Gyeongsang-do from April to November 2013. The concentrations of methanol, crystallized silica glass, formaldehyde and phenol were analyzed by different process - casting process, molding process, core process, and shakeout & finishing process. The highest concentration of methanol was found in casting and molding process, whereas the highest concentration of crystalline quartz(Silica) was observed in core process. The most oxidized steel dusts and the highest concentration of fume were found in shakeout & finishing process. As a result of this study, those labors working at the casting site were found to be constantly exposed to various forms of hazardous chemicals; therefore, it is considered that this is the time to manage and plan how to reduce them. In addition, it is required to thoroughly manage the local exhauster, and improve the process and working environment to reduce various forms of hazardous chemicals.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.17-26
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• 2014

Background: Despite children's unique characteristics that distinguish them from adults, relatively few attempts have been made to measure exposure factors for characterization of children's exposure to hazardous chemicals in child-specific products (CSP). This study was conducted to establish the child-specific exposure factors for exposure and risk assessment of hazardous substances in CSP. Methods: We investigated the exposure factors (e.g., time use of child-products, time and frequency of object-to-body contact, time and frequency of object-to-mouth contact) influencing children's exposure to CSP (e.g., toys, playmats, oil pastels, etc.) in 650 children through a parent-completed questionnaire using a web-based survey. Participants were recruited in five age groups, <1, 1-2, 2-3, 3-6, and 6-12 years of age. Results: The child-specific exposure factors were presented as the mean, median, $95^{th}$ percentile, minimum, and maximum values. Time activity for play mats was the longest among CSP and infants spent more time on them than did elder age groups (189.3-224.7 min/day for <1-2 years vs. 91.2 min/day for 6-12 years). It is apparent that time and frequency of toy block- and plastic toy-to-mouth contact significantly decreased as a function of age. When the variation of CSP use patterns was compared by gender, the only variable that was statistically different between genders was time activity in child-products exposure space. Conclusion: We believe the five child-specific exposure factors suggested in the present study will be valuable for reducing uncertainty in the estimation of chemical exposure during risk assessment of CSP and furthermore, in the appropriate regulations to protect children's health.

• Journal of Environmental Health Sciences
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• v.31 no.2 s.83
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• pp.120-126
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• 2005

To assess exposure of allergy patients to a biological environment, measurements were made of levels of airborne bacteria and fungi, house dust endotoxin and mite allergens in homes of 7 allergy patients and 12 healthy families. Concentrations of airborne total bacteria and the ratio of indoor and outdoor concentrations(I/O) in allergy patient's homes were high compared to non-allergy houses. But no significant differences could be shown for the concentration of spores of viable fungi and staphylococcus in indoor air between the homes of allergic patients and healthy families. The results of investigation on house dust mites, Dermatophagoids farinae were detected in all mattress samples and the levels in the allergy patient's homes were generally high, with individual measurements exceeding $2{\mu}g/g$ dust found in $30\%$ samples. In contrast with, Dermatophagoids pteronyssinus were detected in only $60\%$ samples and the concentrations were very low. The levels of endotoxin in dust samples collected from the allergy patient's home mattresses were higher than those of control houses. There was a positive correlation between the endotoxin levels and the house dust mite allergens.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.9
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• pp.831-837
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• 2015

Many persons and electronic devices are exposed to electromagnetic (EM) waves generated from magnetic resonance imaging (MRI) equipment, EM pulses (EMPs), and many other kinds of EM wave devices. Finger strips are used to provide shielding from these EM waves. Because of the high thermal conductivity of finger strips, they are used in the design of specialized doors that are installed in shielded rooms. In this study, we perform an accelerated life test using the load acceleration stress, which affects the main failure mode of finger strips. We predict the life of the finger strip under normal usage conditions based on the results of the accelerated life test. We compare the results with those predicted from the life test under normal usage conditions to evaluate the validity of accelerated life testing.