• Journal of Environmental Health Sciences
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• v.28 no.3
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• pp.64-71
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• 2002

Hair provides important information about the body's mineral status. Therefore, we have studied the trace elemental distribution in human hair under different inhalation and ingestion environment using neutron activation analysis (NAA). NAA is a powerful analytical method which can be used successfully to determine trace elements in environmental and biological materials. Total diet and six different herbal medicine were analysed to study ingestion environment. Airborne dust in foundry was analysed and compared with outdoor dust to study inhalation environment. Human hairs of common person, herbal medicine taker and foundry worker were analysed to estimate the trace elemental distribution of people under different inhalation and ingestion environment. Analytical results show that herbal medicines contain higher micronutrients such as Ca, Mg, Mn and Cu that total diet and airborne dust in foundry has high Cr. The concentration of Ca, Mg and Mn in hair of herbal medicine taker is two times higher than in hair of common person and Cr con-centration in hair of foundry worker is about three times higher than in hair of common person. These results show that NAA can be used importantly to monitor human health through biological and environmental samples.

• Journal of Yeungnam Medical Science
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• v.36 no.1
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• pp.20-25
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• 2019

Background: The aim of this study was to evaluate the awareness of occupational hazards and personal protective equipment use among dental hygienists (DHs). Methods: A total of 271 self-administered questionnaires were obtained from 280 DHs working at dental hospitals or clinics in Daegu and Gyeongsangbuk-do, Korea. Results: The occupational hazards included work involving dust (94.1%), volatile substances (86.0%), noise (97.0%), and light-curing units (96.7%). The proportion of dental hygiene tasks that participants perceived as harmful were 42.4%, 51.7%, 9.2%, and 31.4% in the same order as above. The proportion of participants who used dust-proof masks during work involving dust was 1.1%. Those who wore gas-proof masks and gloves for work using volatile substances were 0.7% and 31.2%, respectively. Participants who used goggles for work involving light-curing units were 31.0%. None of the participants used ear plugs for work involving noise. A total of 22.9% of the participants recognized the Material Safety Data Sheet, while 79.7% had never been educated about harmful work environments. Conclusion: When compared to exposure status and perception of occupational hazards, the level of protective equipment use was very low. Extra measures to increase DHs' use of personal protective equipment are necessary.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1104-1108
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• 1999

In this study it was focused that if the chrome could be removed in the shaving dust, the reusable protein resource could be recycled from the shaving dust. As the chrome forms a Cr-collagenate by cross linking of collagen in the shaving dust, the dust was steeped for swelling and plumping by $Ca(OH)_2$ solution and then chromium in dust was resolved out by $H_2SO_4$ solution in the first stage process. In the second stage one, dust was swelled and plumped by NaOH solution and then the chromium in dust was oxygenated to a hexavalent chrome, which has high solubility in $H_2O_2$ solution. And then the chromium was removed byt he steeping of $H_2SO_4$ solution as the last process. The first stage process was consisted of the sequential steeping of 3%-$Ca(OH)_2$ and $0.8%-H_2SO_4$. In the second stage the total chrome was effectively removed by the sequential steeping of 0.1%-NaOH, $3%-H_2O_2$ and $1%-H_2SO_4$. In the completely dechromated dust, the humidity was measured as 10.68% and the crude protein was contained by 79.81%. Steeping solutions were reused 3 times for chrome removal process, the chrome was entirely removed in shaving dust.

• Journal of environmental and Sanitary engineering
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• v.19 no.4 s.54
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• pp.9-18
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• 2004

In this study, the observation data for the yellow sandy dust phenomena from the year 1999 to 2003 at background sites in Korea were collected at Global Atmospheric Observatory at An-Myeon island and its temporal variation were analyzed. The chemical characteristics of the fine particles were also analyzed in order to evaluate sources of the yellow sandy dust particles. The results showed that the monthly average mass concentration of the fine particles was the highest in springtime and the lowest in summertime in general. The magnitude of its variation was also the highest in March in which the occurrence of yellow sandy dust was the most frequent and thus the number of samples was the largest, while the lowest in June through September. The yearly variation of ion components contributions to the total mass concentration of the fine particles was slowly decreasing, showing that $63\%$ in 1999, $59\%$ in 2000 and $56\%$ in 2003. The most prevalent ion components in the fine particles were found to be $NO_3$ and $SO_4^{2-}$, which are known to be source materials of acidic precipitation, and $NH_4^+$, a neutralizing material of the acid precipitation. Relative proportion of metal components in the fine particles was calculated as $14\%$ in average, and their concentrations are in an order of Fe > Al > Na > Ca > Zn > Pb > Cu > Mn > Ni > Cd > Cr > Co > U. The results indicated that main sources of the metals was soil-originated Fe, Al, Ca, and Mg, and the contribution of anthropogenic air Pollution-originated Zn, Pb, Cu, Mn were also high and keep slightly increasing. Statistical analysis showed that the chemical components could be divided into soil-originated group of Mg, Al, Ca, Fe, and Mn and air pollution-originated group of $NO_3$, Zn, Pb, and they are occupying more than $60\%$of all the components in the dusty sand. The results explain that An-Myeon island is more influenced by soil-originated source than ocean-originated one and also the influencing strength of anthropogenic poilution-originated source is less than $50\%$ of that of soil-originated sources. Compared to non-yellow sandy period, the yellow sandy dust period showed that the amounts of soil-originated $Mg^{2+}$ and $Ca^{2+}$ and ocean-originated $Na^+$ and $Cl^-$ were increased to more than double and the metals of Mg, Al, Ca, Fe were also highly increased, while micro metal components such as Pb, Cd, Zn, which have a tendency of concentrating in air, were either decreased or maintained at nearly constant level. In the period of yellow sandy dust, a strong positive correlation was observed between water soluble ions and between metals in terms of its concentration, respectively. Factor analysis showed that the first group being comprised of about $43\%$ of the total inorganic components was affected by soil and they are ions of $Na^+,\;Mg^{2+}\;and\;Ca^{2+}$ and metals of Na, Fe, Mn and Ni. The result also showed that the metals of Mg and Cr were classified as second group and they were also highly affected by soil sources.

• Economic and Environmental Geology
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• v.43 no.4
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• pp.315-332
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• 2010

All of the water and stone-dust samples with or without flocculant, in and around quarry mines, were analyzed for total concentrations of heavy metals, cyanide(CN), toxic organic compounds and organic phosphorus. Extraction experiments on stone-dust by EDTA and various pH solutions were also carried out, in order to evaluate the contaminant leaching from the long-term heaped stone-dust within quarry mines. The concentrations of $Cr^{6+}$, Hg, CN, TCE/PCE and total phosphorus in all samples (water and stone-dust) were under detection limits, confirming no environmental contamination from stone-dust in quarry mine areas. Lead and cadmium were not detected in all water samples. Copper and zinc were found in some water samples, and arsenic was detected in a few water samples. But they also showed levels much lower than the drinking water standard. Results of the extraction experiments by EDTA and pH solutions showed that Pb, Cr, Cd, Cu and Zn were leached out in less amounts or under detection limits. Arsenic was detected only at pH 3. From above results, we suggested that environmental contamination by quarry mine development is likely to be minor or negligible.

• Journal of the Korean Ceramic Society
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• v.53 no.4
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• pp.444-449
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• 2016

Industrial by-products generated by integrated iron and steel manufacture cause environmental pollution. The by-products contain not only iron element but also harmful substances. Therefore, in view of to waste recycling and environmental preservation, production of sponge iron using the by-product is considered an effective recycling method. In this study, reduction efficiency of pellets from blast furnace dust was measured. Metallization was found to be increased, as $C/Fe_{total}$ ratio and reaction time were increased. The pellets were formed into a globular shape, and calcined for 60 minutes at $1100^{\circ}C$ in an electric furnace. Phase changes were analyzed using an X-ray diffractometer. Microstructures of the pellets were observed by a scanning electron microscope.

• Journal of Korean Society for Atmospheric Environment
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• v.7 no.3
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• pp.197-202
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• 1991

It is observed that the outbreak of dust storms (yellow sand) from Northern China and Mongolia occurs a few times in April 1988 and 1990. It is found that a dust storm initiated with strong gusty winds after the passage of a cold front, particularly after defrost of the ground surface of a source region in the early spring. According to meteorological chart, satellite images and trajectory analyses, dust clouds invaded Korea in April 1988 and 1990 were landing in the sink area after 2 $\sim$ 4 days travelling for 2,000 $\sim$ 3,000 km from a source region. It was also observed that in the west coast total suspended particulated (TSP) were 100 $\sim$ 200 $\mug m^{-3}$ and sulphates $(SO_4=)$ were 3 $\sim$ 10 $\mug m^{-3}$. These values clearly exceed the concentrations of a background level measured in the Arctic and Atlantic Ocean. Trajectory analyses and meteorological analyses suggest that the high values occurred with prevailing westerly flows coming from anthropogenic sources in China. High concentrations of air pollutants occurred in the backside of an anticyclone and in the area "col".col".uot;.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.470-474
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• 2010

Various anti-scattering agents for suppression of dust scattering at waste depository were compared in this study. Based on the price, easy of usage, and no toxicity, 1% of $Al_2(SO_4)_3$ was selected as surface hardening agents. Only lower than 2% of total weight were flied when wind speed was monthly maximum velocity during 1 hr. These results were quite good with comparison of S anti-scattering agents which was made by C company in Korea. When $Al_2(SO_4)_3$ was spread, the surface waste became hard therefore the effect of suppression of scattering dust was long lasting. It was recommend that 2% of $Al_2(SO_4)_3$ was spread to keep suppression of scattering dust when sudden gust of wind such as natural disaster was occurred.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.209-210
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• 2019

This paper investigates and analyzes related systems, policies, and research trends that are used to prepare the operating regulations for drone-based fine dust monitoring and water fog injection systems in small-sized construction site. As a result of the study, we have drawn a total of six major items to consider when drafting the drone related operational regulations. It will also be used as a basis for future development system operation regulations.

• Journal of Korean Society for Atmospheric Environment
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• v.5 no.1
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• pp.68-78
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• 1989

The heavy metal of suspended particulates with human health has long been studied in environmental interest concerned. This study was intended to identify harmful heavy metals of the ambient air borne dusts which were related with the respirable sizes in the aerodynamics. Two sampling sites were selected comparatively; one was in the Shinchon area, which is the commercial district with heavy traffic and the other site was in the Bulgwang area which is residential area. The supended particulates were sampled by high volume air sample with 6 cascade impactor stages. The heavy metals in terms of As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V and Zn were determined by stomic absorption spectrometry or inductively coupled plasma emission spectrometry. The samples weretaken bimothly for seven consecutive days from May 1987 to March 1988. The annual average concentration of the respirable suspended dust of which diameter is less than 10$\mum$ was 152.59 $\mug/m^3$ of the Shinchon air samples; the respirable dust was equivalent to approximately 85% of the total suspended particulates. The annual average concentration of the respirable suspended dust of the Bulgwang air samples was 112.56 $\mug/m^3$; that was approximately 86% of the total suspended particulates. The concentration of heavy metals was investigated in relation to the particle size. The concentration of Cr, Fe, Mn and V were tended to be much more in the coarse particles than in the fine particles. Cd and Pb in the fine particles were more than in the coarse particles. In the partial correlation coefficients; in the Shinchon area, high correlations among Fe, Se and Mn were determined; it is assumed that those sources would be originated from coal, gasolineand diesel. In Bulgwang area, would be high correlation among Fe, Se, Hg and Mn considered to be originated from coal, Bunker-C and heavy oil as well. From the above results, the hazardous heavy merals in air should be measured and controlled in originally their sources.