• Journal of Korean Society for Atmospheric Environment
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• v.18 no.3
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• pp.213-221
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• 2002

The emission characteristics of particulate matter (PMs) and heavy metals from hazardous industrial wast incinerators were investigated. The particle size distribution (PSD) of PM-10 showed different patterns for two tripes of incinerators; stoker and rotary kiln. However both types showed bimodal form at inlet of air pollution control devices (APCD) and each peak (mode) is located at smaller than 1 ${\mu}{\textrm}{m}$ and near 10 ${\mu}{\textrm}{m}$. It could explain the growth of fine PM by nucleation/coagulation/condensation of metal vapors for fine mode. The PSD of PM-10 after APCD was also influenced by APCD types that had different collection mechanism, and both electrostatic precipitator and bag filter showed less collection efficiency for particles ranged from 0.2 to 0.4 ${\mu}{\textrm}{m}$ and led to a mode in the range of 0.2 to 0.8 ${\mu}{\textrm}{m}$. However the hag filter showed two modes of PSD, while the electrostatic precipitator had one peak. The PMs and heavy metals emission factors, the representative value of emission quantity for sources, for tested facilities were developed. The emission factor of uncontrolled total PM and PM-10 were 14.7 and 7.05 kg/ton waste, respectively. The emission factors from this study were a little bit different with those from US EPA AP-42. It may thus be appropriate to use these results in the course of developing national emission factors.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.2
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• pp.183-190
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• 2007

In this study, we have investigated waste incinerators which are one of the major HAPs emission sources. In order to obtain more reliable HAPs emission data from waste incinerators, direct sampling for the possible pollutants from the stack was carried out and the analysis was performed. The purpose of study was to understand the emission status from waste incinerators and recognize the problems and finally to set up a strategy to reduce the HAPs emissions from waste incinerators. The emission concentrations of 8 species of heavy metals and 16 species of PAHs have been analyzed for the first time in Korea. Not only the emission characteristics of HAPs from waste incinerators were identified, but also the analysis of reduction efficiencies for control devices such as BF and wet scrubbing systems was carried out.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.2
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• pp.89-98
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• 1988

This research evaluated factors on cement-based solidification process designed for hazardous sludge produced from electroplating industry. Four factors of sand/cement ratio, water/cement ratio, amount of wet sludge and amount of a precipitator, were investigated in terms of leachability and compressive strength of the solidified materials. Results of triplicate tests and statistical analysis indicated that sand/cement ratio(S/C) had the greatest effect on leaching of Cr(VI) from the solidified materials while water/cement ratio(W/C) on Zn and compressive strength. Cr(VI) was fixed better than Zn by portland cement. An experimental modeing was developed to estimate leached metal concentration and compressive strength at a given condition. Proper mixing criteria were also suggested for the use of the solidified mixture as construction materials. In solidification of 30g dry sludge, optimal condition was studied for S/C ratio, W/C ratio and the weight of precipitator which were 1, 1.5 and 1.075g respectively.

• Journal of Environmental Health Sciences
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• v.36 no.5
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• pp.418-434
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• 2010

As concerns regarding water pollution grow, the need increases for a fast and accurate assessment of ecological risk. In this context, many studies have been conducted to identify biomarkers which can sensitively indicate exposure to and effects of various contaminants in a water environment. However, the utility of most such biomarkers in the real water environment is not yet validated. In this paper, we conducted a thorough review of publications that were related to developing or evaluating molecular and biochemical biomarkers of freshwater fish in ecological risk assessment, and evaluated whether these biomarkers of interest could link to the effects on higher biological levels, such as histopathology and above. Biomarkers of interest included those associated with metabolism, oxidative stress, reproduction and endocrine disruption, genotoxicity, and defense against heavy metal exposure. We found that, when used alone, most molecular and biochemical biomarkers are not sufficient to understand the effects of toxic substances in higher biological levels, due to defense or acclimation mechanisms of organisms. Moreover, some biomarkers respond not only to hazardous substances but also to the changes in water quality and disease outbreak. Molecular and biochemical biomarkers may be most useful in understanding the potential biological effects of toxic compounds when used in parallel with relevant endpoints of higher biological levels.

• Journal of Environmental Health Sciences
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• v.45 no.1
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• pp.54-61
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• 2019

Objectives: In this study, we investigated an assessment for exposure levels of hazardous substances to kids cafes that unregulated by law. Methods: Heavy metals, volatile organic compounds, formaldehyde, pesticides and phthalate were measured at 20 kids cafes in Gyeonggi-do and Incheon. Samplings were conducted from April to July in 2018. Results: Heavy metals were detected over the standard mainly around the floor and walls in the 19 kids cafes. Pesticides were detected in 7 locations with chlorpyrifos, diazinon and cypermethrin, and showed the highest detection level of chlorpyrifos. The concentrations of DEHP in all kids cafes were exceeded with standard. The risk assessment results showed that HCHO as carcinogen had a safety level and DEHP as non-carcinogens had a safety level as assessed to be under than 0.1. Conclusions: Considering the exposure investigation results and the importance of child health protection, kids cafe should be included in the legal management list of children's activities zones.

• Journal of Sensor Science and Technology
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• v.31 no.3
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• pp.163-167
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• 2022

In this study, we investigated a carbon nanotube (CNT) film sensor to detect hazardous and noxious substances distributed in seawater. The response change of the sensor was studied according to environmental temperature, and its temperature coefficient of resistance (TCR, α) was measured. The temperature of the CNT film (~50 ㎛) was in the range of 20-50 ℃, and αCNT was calculated to be -0.0011 %/ ℃. We experimentally confirmed that the CNT film had a smaller TCR value than that of the conventional sensor. Therefore, we investigated the response change of the CNT sensor according to temperature. The CNT sensor showed a relatively small error of approximately 2.3 % up to 30 ℃, which is within the temperature range of the seawater of the Korean Peninsula. However, when the temperature exceeded 40 ℃, the error in the CNT sensor increased by more than 5.2 %. We fabricated a metal oxide (ITO, indium-tin-oxide) film and compared its performance with that of the CNT sensor. The ITO sensor showed an error of >12.5 % at 30 ℃, indicating that in terms of the stability of the sensor to temperature, the CNT film sensor has superior performance.

• Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.313-318
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• 2014

From 2008 to 2013, the mussel Mytilus galloprovincialis were collected from a major area of mussel production (Changseon area), which is a designated shellfish-cultivating area for export, located on the southern coast of Korea. The samples were analyzed for mercury (Hg) using a direct Hg analyzer and for other metals, such as cadmium (Cd), lead (Pb), arsenic (As), chromium, copper, nickel, and zinc, using inductively coupled plasma mass spectrometry. The concentrations and bioaccumulation of the heavy metals were determined, and a potential risk assessment was conducted to evaluate their hazards towards human consumption. The concentration and bioaccumulation ratio of Cd were the highest of the three hazardous metals (Cd, Pb, and Hg). The concentrations of hazardous metals in all samples were within the limits set by Korea and other countries. The estimated dietary intake (EDI) was compared to the provisional tolerable daily intake (PTDI) adopted by the Joint FAO/WHO Expert Committee on Food Additives and the U.S. Environmental Protection Agency. The EDIs of all heavy metals tested for mussel samples ranged from 0.01 to 4.99% of the PTDI; the highest value was measured for As. The hazard index (HI) can be used to assess the risk of heavy metal consumption associated with contaminated food. The HI for all samples was far less than 1.0, which indicates that the mussels produced in the Changseon area do not represent an appreciable hazard to humans and are fit for consumption.

• Journal of the Korean Ceramic Society
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• v.39 no.12
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• pp.1138-1142
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• 2002

Slag cement and supersulfated slag cement were fabricated by mixing blast furnace slag and ordinary portland cement and adapted to solidify/stabilize heavy metal contained hazardous waste sludge. In case of slag cement, it showed continuous increase of their compressive strengths, which is attributed to the formation of the C-S-H, ettringite and monosulfate with STS sludge. However, BF and COREX sludge has a different shape and composition. therefore, adequate compressive strength could not be achieved with this slag cement. In case of the mixture of the each sludge like the STS-BF or the STS-COREX, the compressive strength over the standard level for disposing the wastes could be obtained with slag cement. The supersulfated slag cement that contain accelerators was very effective in solidifying the COREX sludge, which was difficult to solidify using different cement and obtained high compressive strength only for 3 days.

• Journal of Mushroom
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• v.19 no.1
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• pp.51-55
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• 2021

The mineral contents of domestic and Chinese Sarcodon aspratus were analyzed for comparing the differences in the mineral contents according to the production sites. The mineral contents of 10 domestic and 10 Chinese S. aspratus were analyzed by using an atomic absorption spectrophotometer and an inductively coupled plasma mass spectrometer. The sodium, magnesium, potassium, and calcium contents of domestic S. aspratus were 170.3±44.0 mg/kg, 81.3±20.8 mg/kg, 1,123.8±274.3 mg/kg, and 12.1±4.1 mg/kg, respectively, while those of Chinese S. aspratus were 112.2±40.8 mg/kg, 297.8±20.9 mg/kg, 10,938.4±2,914.1 mg/kg, and 52.5±27.7 mg/kg, respectively. There were no significant differences in the micro mineral contents and hazardous heavy metal contents between domestic and Chinese S. aspratus, while there was a significant difference in the macro mineral contents between domestic and Chinese S. aspratus. Thus, the comparative analyses of the sodium, magnesium, potassium, and calcium contents of many domestic and Chinese S. aspratus are required to determine their production sites in the future.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.301-311
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• 2015

Objectives: Operators of overhead traveling crane in a ship assembly factory perform work to transmit large vessel blocks to an appropriate working process. Hazardous matters such as metal dusts, carbon monoxide, carbon dioxide, ozone, loud noise and fine particles are generated by variable working activities in the factory. The operators could be exposed to the hazardous matters during the work. In particular, welding fumes comprised of ultra fine particles and heavy metals is extremely hazardous for humans when exposing a pulmonary through respiratory pathway. Occupational lung diseases related to welding fumes are increasingly on an upward tendency. Therefore, the objective of this study is to assess properly unknown occupational exposure to the welding fumes among the operators. Methods: This study intended to clearly determine an equivalence check whether or not chemical constituents and composition of the dusts, which existed in the driver's cab, matched up with generally known welding fumes. Furthermore, computational fluid dynamics program(CFD) was used to identify a ventilation assessment in respect of a contamination distribution of welding fumes in the air. The operators were investigated to assess personal exposure levels of welding fumes and respirable particulate. Results: The dust in an operation room were the same constituents and composition as welding fumes. Welding fumes, which caused by the welding in a floor of the factory, arose with an ascending air current up to a roof and then stayed for a long time. They were considered to be exposed to the welding fumes in the operation room. The personal exposure levels of welding fumes and respirable particulate were 0.159(n=8, range=0.073-0.410) $mg/m^3$ and 0.138(n=8, range=0.087-0.178) $mg/m^3$, respectively. They were lower than a threshold limit value level($5mg/m^3$) of welding fumes. Conclusions: These findings indicate that an occupational exposure to welding fumes can exist among the operators. Consequently, we need to be keeping the operators under a constant assessment in the operator process of overhead traveling crane.