• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.104-114
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• 2015

Objectives: The purpose of this study is to investigate the atmospheric concentration of VOCs and the urinary concentration of t,t-MA, HA, MA in the industrial complex of Yeosu, South Jeolla Province. Methods: In order to study seasonal patterns of air concentration of VOCs, measurements were taken at five sampling sites around Yeosu from June 2013 to June 2014. Urinary metabolite excretionsfrom 671 subjects, exposure and comparison area were analyzed. Results: The average concentration of VOCs in the air was 1.53ppb for benzene, 0.73ppb for toluene, 0.22ppb for ethylbenzene, 0.52ppb for xylene and 0.12ppb for styrene. The concentration of benzene was somewhat higher than the year-average standard ($5{\mu}g/m^3$, about 1.5ppb) of the domestic air-environment criteria newly established in 2010.The metabolic concentration of VOCs in the urine of the entire sample was analyzed at $47.76{\mu}g/g\;cr.$, 213.07mg/g cr., and $290.09{\mu}g/g\;cr.$ for t,t-MA, HA, and MA, respectively. Compared with the average values for Korea as presented in the first basic survey of national environmental conservation ( $49.8{\mu}g/g\;cr.$ for t,t-MA, 0.17g/g cr. for HA, and 0.26mg/g cr. for MA), the metabolic concentrations of HA and MA in urine were higher than the average values. Conclusions: The concentration of VOCs in the air and urinary metabolites of the exposed and control areas showed that the concentrations of all substances were higher in the exposed area than in the control area.

• Safe Food
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• v.3 no.1
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• pp.13-21
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• 2008

우리나라 학교급식의 현재 성적표를 "양적 성공, 질적 실패"로 평가할 수 있다. 2003년 학교급식이 국가적 교육사업이 되어서 초 중 고 특수학교에서 전면급식이 이루어지고 10,343개교에서 704만명의 학생에게 급식을 제공하고 있다. 현재는 양질의 학교급식을 안전하고 저렴하게 공급하고, 국가식량정책과 연계하여 효율적으로 관리하여야 할 시기이다. 그러나 학교급식 소요경비 연 2조3천억원, 영양사 7,196명 등 63,145명이 종사하는 거대한 산업군이라는 규모에도 불구하고 전체 학교의 70%만이 식당시설을 갖추고 있고 급식 만족도가 학생이나 학부모의 기대에 미치지 못하고 있으며, 식중독 발생의 원흉이 되어 국민적 질책의 대상이 되고 있는 것이 현실이다. 이 문제는 1) 영양사 업무과중에 따른 시간부족, 영양사 지식정보 부족 등에 따른 식재료 및 위생관리 소홀, 2) 냉장, 냉동, 오염/비 오염 구획 등에 필요한 시설과 설비 부족, 3) 교육인적자원부의 급식위생관리의 전문성 부족과 담당 인력 및 정책적, 재정적 지원 부족을 원인으로 볼 수 있다. 학교급식 안전대책은 아래 20대 과제를 추진하여 확보하여야 할 것이다. 전략 1은 "우수한 식재료 위생관리"로서 "급식비 인상 및 현실화, 철저한 수입 농수축산물관리, 식재료 공급 및 전처리업 자유업에서 신고제, 허가제로 전환, GAP(우수농산물관리) 제도 도입, 생산이력제도(traceability) 도입, 급식원료 "품질인증 제도" 도입, 식품원료 전처리 시 세척, 소독프로그램 보급, 학교급식 식자재기준, 규격 설정, 과학적이고 쉬운 검수지침 개발 및 보급, 신속검사키트를 활용한 주기적인 미생물 검사 의무화, 위생 전문가에 의한 검수, 식재료별로 분산된 법령과 관리제도 정비(식품안전기본법), 급식식자재 공급 유통 과정의 감시 감독 강화" 등 13개 과제를 제안한다. 전략 2는 "급식위생 확보 인프라구측"으로서 "급식종사자 전문성 확보(조리/영양/위생), 급식전담기구(학교급식진흥원 /학교급식센터 등) 설치, 급식형태 다양화(위탁/직영 균형 발전), 학교급식법 재개정, 학교급식 HACCF제도 확대" 등 4개 과제를 제안한다. 전략 3은 "급식소 시설 설비 현대화 및 환경개선"으로서 "급식시설 설비 현대화 (전처리실, 냉장고, 온장고 구비 등), 급식소 환경 개선 (상수 사용 확대 및 안전강화, 지하수 소독 강화, 정화된 공기 공급 등)" 등 2개 과제를 제안한다. 전략4는 "급식위생제도 및 관리체계 개선"으로서 "전문적 단일기관 안전관리 (식품안전처)" 과제를 제안한다.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.3
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• pp.139-145
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• 2011

Objectives: This investigation is purposed to evaluate the airborne asbestos concentrations in the public buildings having asbestos containing materials(ACMs) in Seoul. Methods: The Seoul Metropolitan Government carried out an asbestos survey to the city-owned public buildings to identify the level of risk exposure, classified into low, moderate and high risk. To evaluate the airborne concentration of asbestos, 11 sampling sites in ten buildings based on the survey were selected. The air samples from the eleven sites were analyzed by Phase Contrast Microscopy(PCM) and Transmission Electron Microscopy (TEM), and compared the analytical results from the both. Results: 1. The airborne fiber concentrations by PCM were less than the detection limit($7f/mm^2$) in 9(82%) out of 11 sampling sites. The highest concentration was 0.0043 f/cc, but it was below the guideline value for indoor air quality(0.01 f/cc), proposed by the Ministry of Environment, Korea. 2. In two sampling sites, having moderate risk level, the chrysotile was identified and showed it's concentrations of 0.0102 s/cc and 0.0058 s/cc, less than $5{\mu}m$ lengths. 3. The ACMs identified in the two sampling sites were a packing material(65% of chrysotile) in mechanical area and a thermal system insulation(5% of chrysotile) in a boiler room. Having more possibility of asbestos emission in the mechanical area, it would be required to set up and carry out the asbestos management plan. Conclusions: Based on the result of this study, the airborne asbestos concentrations in the public buildings with ACMs were generally lower than the guideline value for indoor air quality. There are widespread concerns about the possible health risk resulting from the presence of airborne asbestos fibers in the public buildings. Most of the previous studies about airborne asbestos analysis in Korea were performed based on PCM method that asbestos and non-asbestos fibers are counted together. In the public and commercial buildings, having ACMs, it is suggested that the asbestos be analyzed by TEM method to identify asbestos due to concerns about asbestos exposure to workers and unspecified people.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.8-13
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• 2018

Nitrogen oxides (NOx) have recently been very influential in the generation of ultrafine dust, which is of great social interest in terms of improving the atmospheric environment. Nitrogen oxides are generated mainly by the reaction of nitrogen and oxygen in air in a combustion gas atmosphere of high temperature in a combustion apparatus such as thermal power generation. Recently, research has been conducted on the combustion that recirculates the exhaust gas to the cylindrical burner by using a piping using a Coanda nozzle. In this study, three types of burners were carried out through computational fluid analysis. Case 1 burner with the outlet of the combustion gas to the right, Case 2 burner with both sides as gas exit, Case 3 burner with left side gas exit. The pressure, flow, temperature, combustion reaction rate and distribution characteristics of nitrogen oxides were compared and analyzed. The combustion reaction occurred in Case 1 and Case 2 burner in the right direction with combustion gas recirculation inlet and Case 3 burner in the vicinity of mixed gas inlet. The temperature at the outlet was about $100^{\circ}C$ lower than that of the other burners as the Case 2 burner was exhausted to both sides. The NOx concentration of Case 1 burner at the exit was about 20 times larger than that of the other burners. From the present study, it could be seen that it is effective for the NOx reduction to exhaust the exhaust gas to both side gas exits or to exhaust the exhaust gas to the opposite direction of inlet of recirculation gas.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1825-1832
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• 2000

Column experiments were conducted by using soil columns, to investigate feasibility and efficiency of in-situ ozone enhanced remediation for diesel-contaminated soil. The injection of gaseous ozone into soil column revealed the enhanced decomposition of ozone due to the catalytic reaction between ozone and metal (e.g., Fe, Mn etc.) oxides as evidenced by as much as 25 times shorter half-life of ozone in a sand packed column than in a glass beads packed column. Substantial retardation in the transport of and the consumption of ozone were observed in the diesel contaminated field soil and sand packed columns. After 16 hrs ozonation, 80% of the initial mass of diesel (as diesel range organic) concentration of $800{\pm}50mg/kg$, was removed under the conditions of the flow rate of 50mL/min and $6mg-O_3/min$. Whereas, less than 30% of diesel was removed in the case of air injection. Analysis of the residual TPH(total petroleum hydrocarbon) and selected 8 aliphatics of diesel compounds in the inlet and the outlet of the column confirmed that diesel nonselectively reacted with ozone and then shifted to lower carbon numbered molecules. Water content also was found to be an important parameter in employing ozone to the hydrocarbon-contaminated soil.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.3
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• pp.136-143
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• 2006

The study was carried out to evaluate odor emission during storage time and quality of liquid slurry fertilizer along with three storage container types installed at farmer's fields in Cheorwon. Liquid slurry manure stored in the liquid-circulated or the air-injected tank was very homogeneous in concentration of nutritional elements because of well mixing operation, while nutritional concentration of the manure stored in the non-treated tank was significantly different from top to bottom in the tank, which may bring about partially irregular growth of plant after its application. The potential capacity of offensive odor emitted from liquid slurry manure stored in the liquid-circulated or the air-injected tank was much lower than that emitted from manure stored in the non-treated tank. Low potential capacity may less emit offensive odor after application of piggery liquid slurry on the field. The efficiency in oder to reduce odor emission from liquid manure was slightly higher in the liquid-circulated tank than the air-injected tank

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.1
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• pp.47-52
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• 2010

Green tobacco sickness (GTS) is known as an occupational disease among tobacco harvesters, and a form of acute nicotine intoxication by the absorption of nicotine through the skin from the wet green tobacco plant. On the assumption that GTS may occur by inhalation as well as absorption of nicotine, we measured the airborne nicotine concentration in tobacco field and the processing room of tobacco leaves. We measured the airborne nicotine concentrations in the tobacco field and processing room between 13 and 30 July 2008. All sampling and analyses of airborne nicotine were conducted according to the manual of analytic methods of NIOSH 2551, and we sampled 2 times at 11 points in the tobacco field by area sampling. The sampling in the processing room of tobacco leaves was conducted at 3 points, and earlymorning dew was collected from the tobacco by wringing the moisture into specimen bottles. The airborne nicotine concentration [geometric mean (geometric standard deviation)] in the tobacco field in the P.M. was higher [49.2 mg/$m^3$ (1.3)] than the A.M. concentration [43.4 mg/$m^3$ (1.4)]. Similarly, the nicotine concentration in the processing room of tobacco leaves was 224.4 mg/$m^3$ (1.2), and the concentration of nicotine in the dew was 64.7 mg/${\ell}$ (1.7). Based on our results, the airborne nicotine concentration in the tobacco field and the processing room of tobacco leaves were 100 and 400 times higher than the occupational recommended values (TLV-TWA of 0.5 mg/$m^3$), respectively. In the future, it is hoped that epidemiologic studies and environmental measurements will be conducted for GTS which occurs by inhalation of nicotine. If GTS is confirmed to occur by inhalation of nicotine, respiratory and dermal protective equipment must be distributed.

• Journal of Radiation Protection and Research
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• v.27 no.1
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• pp.27-35
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• 2002

Characteristics of Amberlite IRN 77, a cation exchange resin, and the mechanisms of its adsorption equilibria with Co(II), Ni(II), Cr(III) and Fe(III) ions were investigated for the application of the demineralizing process in the primary coolant system of a pressurized water reactor (PWR). The optimum dosage of the resin for removal of the dissolved metal ions at $200mgL^{-1}$ was 0.6 g for 100 mL solution. Most of each metal ion was adsorbed onto the resin in an hour from the start of the reaction. Each metal adsorption onto the resin could be well represented by Langmuir isotherms. However, in the case of Fe(III) adsorption, continuous formation of Fe-oxide or -hydroxide and its subsequent precipitation inhibited the completion of the equilibrium between the metal and the adsorbent Cobalt(II) and Ni(II), which have an equivalent electrovalence, were adsorbed to the resin with a similar adsorption amount when they coexisted in the solution. However, Cr(III) added to the solution competitively replaced Co(II) and Ni(II) which were already adsorbed onto the resin, resulting in desorption of these metals into the solution. The result was likely due to a higher adsorption affinity of Cr(III) than Co(II) and Ni(II). This implies that the interactively competitive adsorption of multi-cations onto the resin should be fully considered for an efficient operation of the demineralizing ion exchange process in the primary coolant system.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.4
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• pp.261-271
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• 2007

To provide necessary information for future environmental monitoring of storage batteries in Korea, authors analyzed environmental monitoring dataset of air lead concentration of 12 storage battery industries measured during 1989-2006. We calculated geometric mean and standard deviation with minimum and maximum value of each year dataset. Air lead concentration data were analyzed according to year of measurement, type of grid manufacturing method (grid casting type or expander type), size of industries and type of operation (casting, lead powder & pasting, assembly and others). The geometric mean and standard deviation of all lead industries for overall 18 years were $72{\mu}g/m^3$ and 3.65 with minimum of $6{\mu}g/m^3$ and maximum of $7,956{\mu}g/m^3$. The geometric mean air lead concentrations of years between 1989-1999 were above the Korean PEL($50{\mu}g/m^3$), whereas those of years after year 2000 were below the Korean PEL showing 50% of it. The geometric mean concentration of air lead was significantly lower in expander method battery industries than that of grid method battery industries and was lower in large sized battery industries than small & medium sized ones throughout the whole 18 years period. The distributions of over PEL($50{\mu}g/m^3$) were decreased by the years of environmental monitoring and those were lower in expander method battery industries than grid method battery industries. The significant reduction of mean air lead concentration during last 10 years may be induced partly due to more active environmental engineering control and new introduction of new operation in grid method battery industries, but may be also influenced by non-engineering method such as reduction of operation hours or reduction of exposure time during actual environmental measurement by industrial hygienist which is not concrete evidence, but just circumstantial evidence.

• Journal of Radiation Protection and Research
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• v.24 no.4
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• pp.205-213
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• 1999

Effective dose conversion coefficients from unit activity radionuclides contaminated on the ground surface were calculated by using MCNP4A rode and male/female anthropomorphic phantoms. The simulation calculations were made for 19 energy points in the range of 40 keV to 10 MeV. The effective doses E resulting from unit source intensity for different energy were compared to the effective dose equivalent $H_E$ of previous studies. Our E values are lower by 30% at low energy than the $H_E$ values given in the Federal Guidance Report of USEPA. The effective dose response functions derived by polynomial fitting of the energy-effective dose relationship are as follows: $f({\varepsilon})[fSv\;m^2]=\;0.0634\;+\;0.727{\varepsilon}-0.0520{\varepsilon}^2+0.00247{\varepsilon}^3,\;where\;{\varepsilon}$ is the gamma energy in MeV. Using the response function and the radionuclide decay data given in ICRP 38, the effective dose conversion coefficients for unit activity contamination on the ground surface were calculated with addition of the skin dose contribution of beta particles determined by use of the DOSEFACTOR code. The conversion coefficients for 90 important radionuclides were evaluated and tabulated. Comparison with the existing data showed that a significant underestimates could be resulted when the old conversion coefficients were used, especially for the nuclides emitting low energy photons or high energy beta particles.