• Title/Summary/Keyword: Complex exposure

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Hevey Metal Levels in Urine of Residents in Industrial Area (일부 공단지역 주민의 요 중 중금속 농도에 관한 연구)

  • Jou, Hye-Mee;Choi, Su-Hyeon;Chung, Eun-Kyung;Jung, Soon-Won;Yang, Won-Ho;Son, Bu-Soon
    • Journal of Environmental Science International
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    • v.20 no.5
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    • pp.565-574
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    • 2011
  • This study analyzed the concentration of the heavy metals(Cd, Hg, iAs) of urine(n=576) from May, 2007 to Oct 2007. The subject was residents in G, Y, H industrial area, Jeollanam-do, in which exposure due to the adjacency of the industrial complex. As to the heavy metal concentration in the urine of the residents in the whole exposed region and the comparing region, the content of cadmium, mercury, and inorganic arsenic in the exposed region group were 1.23, 1.85, and 8.80 ${\mu}g$/g_ct respectively, and those of the comparing region group were 1.87, 2.00, and 8.93 ${\mu}g$/g_ct respectively, which indicates that the concentration of the comparing group was higher than that of the exposed group. The heavy metal concentration for each age group increased in proportion to age except those under 10 for some substances(p<0.01). As to geometric mean concentration cadmium and inorganic arsenic in urine according to the smoking history of the subject, the concentration of the smoking group and the non-smoking group were 1.65 ${\mu}g$/g_ct and 9.13 ${\mu}g$/g_ct respectively, while those of the non-smoking group were 1.47 ${\mu}g$/g_ct and 8.91 ${\mu}g$/g_ct respectively, which indicates that the former is higher than the latter. As to the inorganic arsenic concentration in urine according to the food preference, in order of vegetable, fish, and meat showed high concentration (p<0.01). To clarify the factors affecting the heavy metal concentration in urine among the subjects, the multiple regression analysis was conducted. As a result, it turned out that as to cadmium content in urine, gender, age, drinking, and smoking have influence on the subjects, with explanatory adequacy of 37.5 %.

Toxicity and Endocrine Disrupting Effect of Parabens (파라벤류의 독성과 내분비계장애 효과)

  • Ahn, Hae-Sun;Nah, Won-Heum;Lee, Jae-Eun;Oh, Yeong-Seok;Gye, Myung-Chan
    • Korean Journal of Environmental Biology
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    • v.27 no.4
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    • pp.323-333
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    • 2009
  • Parabens are alkyl esters of p-hydroxybenzoic acid, which are widely used in foods, cosmetics, and pharmaceutic products as preservatives. Absorbed parabens are metabolized fastly and excreted. Actually human body is exposed to complex mixture of parabens. Safety assessment at various toxicological end points revealed parabens have a little acute, subacute and chronic toxicities. Some reports have argued that as parabens have estrogenic activity, they are associated with the incidence of breast cancer through dermal absorption by cosmetics. There is an inference that antiandrogenic activity of parabens may give rise to a lesion of male reproductive system, but also there is an contrary. At cellular level, parabens may inhibit mitochondrial function of sperms and androgen production in testis, but also there is an contrary. Parabens seem to have little or no toxicity in embryonic development. Parabens can cause hemolysis, membrane permeability change in mitochondria and apoptosis, suggesting cellular toxicity of parabens. Parabens evoked endocrine disruption in several fish species and have toxic effect on small invertebrates and microbes. Therefore, the toxicity of parabens should be considered as a potentially toxic chemical in the freshwater environment. In conclusion, though parabens may be considered as a low toxic chemical, more definite data are required concerning the endocrine disrupting effect of parabens on human body and aquatic animals according to route and term of exposure as well as the residual concentration of parabens.

A Study on the Application of Potential Exposed Population for a Receptor-oriented Health Impact Assessment (수용체 지향의 건강영향평가를 위한 잠재노출 인구수의 산정·활용 가능성 연구)

  • Ha, Jongsik
    • Journal of Environmental Impact Assessment
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    • v.27 no.2
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    • pp.194-202
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    • 2018
  • Health impact assessment in South Korea is carried out within the framework of Environmental Impact Assessment (EIA). And, public health and hygiene items in EIA as an evaluation of health impact items were designed to calculate the emission level of hazardous air pollutants from specific development projects, and the exposure concentration at major sites, and to assess the health risk associated with these projects. But, the assessment of the receptor characteristics around the development project is limitedly considered. The purpose of this study is to propose the method of calculation of potential exposed population and the use of it for public health and hygiene items in EIA. The data for the calculation of potential exposed population in South Korea were identified. And the calculation algorithm based on them was proposed. After that, in a development of industrial complex, a case analysis was carried out assuming the release of hazardous air pollutants. This study suggested that the concept of population risk should be applied in risk assessment utilizing the potential exposed population and as a future study, a standard of assessment of health effects for population risk should be established. Finally, the possibility of using this study as a location-limiting tool for the development project was presented through the method of calculating the potential exposed population. It is meaningful that this study presented a method for performing risk assessment from the perspective of receptors around a development project.

A study on the Construction Claims Between Parties Without Privity (국내 건설분쟁에서 비계약 당사자간의 건설분쟁에 관한 연구)

  • Yun Dae-Jung;Han Sung-Heon;Paek Joon-Hong
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.300-305
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    • 2002
  • The construction project is a complex undertaking involving multiple participants. Conflicts are inherently natural in the construction projects and subsequently, a success of projects mainly depends on how well to cope with the conflicts. In the past, courts usually took the position that the professional's exposure in damages for negligent performance of any of his/her duties would not extend to strangers to the contractual arrangement. However, courts today generally reject that rationale which was earlier in vogue and protect architects, engineers, and contractors from being liable to third parties. It means that the lack of privity of contract could rarely protect a profession in a suit alleging the negligence or professional malpractice in preparing plans or specifications. The main goal of this paper is to enhance the understanding of the legal aspect of privity and to provide the trend of no-privity disputes through the analysis of lawsuit cases during the last 40 years. On the base of the analysis, importance of the third relationship and the liability in construction disputes is presented.

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An Analysis of the Symbiotic Star Z And Line Profile (공생별 Z And의 선윤곽 분석)

  • Lee, Seong-Jae;Hyung, Siek;Lee, Kangwhan
    • Journal of the Korean earth science society
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    • v.33 no.7
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    • pp.608-617
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    • 2012
  • The symbiotic nova Z Andromedae (And) was investigated, using the high dispersion spectra of spectral resolution, ${\Delta}{\lambda}{\sim}-0.1{\AA}$. The spectral observations were done with (1) the Hamilton Echelle Spectrograph (HES) and the high resolution spectra (exposures=1800s and 3600s) were obtained at Lick Observatory in 2001 August $30^{th}$ (phase ${\Phi}$=0.77), and 2002 August $12^{th}$ (phase ${\Phi}$=0.22), (2) with the Bohyunsan Echelle Spectrograph (BOES) at Bohyunsan Optical Astronomy Observatory and the high resolution spectra (exposure=1200s) were secured in 2009 October $21^{st}$ (phase ${\Phi}$=0.70). From both the HES and BOES spectral data in the $3600{\AA}-9500{\AA}$ wavelengths, we extracted the emission lines of HI, HeI, and HeII, which have been decomposed into double or triple Gaussian components for 3 consecutive phases. The emission zones responsible for these components appear to be closely related with the orbital motion of a white dwarf or a giant star. The presence of the Raman scattering $H{\alpha}$ broad wing feature and the kinematic characteristics of the line profile observed in each phase imply that the Z And emission lines are mostly from two Lagrangian points, $L_1$ and $L_2$, and the accretion disk around the white dwarf star. The Z And was most active in 2009 and 2001 during the outburst phase, while it remained quiescent in 2002 in spite of the complex line profiles.

Assessment of the Abuse Liability of Synthetic Cannabinoid Agonists JWH-030, JWH-175, and JWH-176

  • Tampus, Reinholdgher;Yoon, Seong Shoon;Pena, June Bryan de la;Botanas, Chrislean Jun;Kim, Hee Jin;Seo, Joung-Wook;Jeong, Eun Ju;Jang, Choon Gon;Cheong, Jae Hoon
    • Biomolecules & Therapeutics
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    • v.23 no.6
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    • pp.590-596
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    • 2015
  • The emergence and use of synthetic cannabinoids have greatly increased in recent years. These substances are easily dispensed over the internet and on the streets. Some synthetic cannabinoids were shown to have abuse liability and were subsequently regulated by authorities. However, there are compounds that are still not regulated probably due to the lack of abuse liability studies. In the present study, we assessed the abuse liability of three synthetic cannabinoids, namely JWH-030, JWH-175, and JWH-176. The abuse liability of these drugs was evaluated in two of the most widely used animal models for assessing the abuse potential of drugs, the conditioned place preference (CPP) and self-administration (SA) test. In addition, the open-field test was utilized to assess the effects of repeated (7 days) treatment and abrupt cessation of these drugs on the psychomotor activity of animals. Results showed that JWH-175 (0.5 mg/kg), but not JWH-030 or JWH-176 at any dose, significantly decreased the locomotor activity of mice. This alteration in locomotor activity was only evident during acute exposure to the drug and was not observed during repeated treatment and abstinence. Similarly, only JWH-175 (0.1 mg/kg) produced significant CPP in rats. On the other hand, none of the drugs tested was self-administered by rats. Taken together, the present results indicate that JWH-175, but not JWH-030 and JWH-176, may have abuse potential. More importantly, our findings indicate the complex psychopharmacological effects of synthetic cannabinoids and the need to closely monitor the production, dispensation, and use of these substances.

A Study on Segmentation Process of the K1 Reactor Vessel and Internals (K1 원자로 및 내부구조물 절단해체 공정에 대한 연구)

  • Hwang, Young Hwan;Hwang, Seokju;Hong, Sunghoon;Park, Kwang Soo;Kim, Nam-Kyun;Jung, Deok Woon;Kim, Cheon-Woo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.4
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    • pp.437-445
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    • 2019
  • After the permanent shutdown of K1 in 2017, decommissioning processes have attracted great attention. According to the current decommissioning roadmap, the dismantling of the activated components of K1 may start in 2026, following the removal of its spent fuel. Since the reactor vessel (RV) and reactor vessel internal (RVI) of K1 contain massive components and are relatively highly activated, their decommissioning process should be conducted carefully in terms of radiological and industrial safety. For achieving maximum efficiency of nuclear waste management processes for K1, we present activation analysis of the segmentation process and waste classification of the RV and RVI components of K1. For RVI, the active fuel regions and some parts of the upper and lower active regions are classified as intermediate-level waste (ILW), while other components are classified as low-level waste (LLW). Due to the RVI's complex structure and high activation, we suggest various underwater segmentation techniques which are expected to reduce radiation exposure and generate approximately nine ILW and nineteen very low level waste (VLLW)/LLW packages. For RV, the active fuel region and other components are classified as LLW, VLLW, and clearance waste (CW). In this case, we suggest in-situ remote segmentation in air, which is expected to generate approximately forty-two VLLW/LLW packages.

Chronic Administration of Baicalein Decreases Depression-Like Behavior Induced by Repeated Restraint Stress in Rats

  • Lee, Bombi;Sur, Bongjun;Park, Jinhee;Kim, Sung-Hun;Kwon, Sunoh;Yeom, Mijung;Shim, Insop;Lee, Hyejung;Hahm, Dae-Hyun
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.5
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    • pp.393-403
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    • 2013
  • Baicalein (BA), a plant-derived active flavonoid present in the root of Scutellaria baicalensis, has been widely used for the treatment of stress-related neuropsychiatric disorders including depression. Previous studies have demonstrated that repeated restraint stress disrupts the activity of the hypothalamic-pituitary-adrenal (HPA) axis, resulting in depression. The behavioral and neurochemical basis of the BA effect on depression remain unclear. The present study used the forced swimming test (FST) and changes in brain neurotransmitter levels to confirm the impact of BA on repeated restraint stress-induced behavioral and neurochemical changes in rats. Male rats received 10, 20, or 40 mg/kg BA (i.p.) 30 min prior to daily exposure to repeated restraint stress (2 h/day) for 14 days. Activation of the HPA axis in response to repeated restraint stress was confirmed by measuring serum corticosterone levels and the expression of corticotrophin-releasing factor in the hypothalamus. Daily BA administration significantly decreased the duration of immobility in the FST, increased sucrose consumption, and restored the stress-related decreases in dopamine concentrations in the hippocampus to near normal levels. BA significantly inhibited the stress-induced decrease in neuronal tyrosine hydroxylase immunoreactivity in the ventral tegmental area and the expression of brain-derived neurotrophic factor (BDNF) mRNA in the hippocampus. Taken together, these findings indicate that administration of BA prior to the repeated restraint stress significantly improves helpless behaviors and depressive symptoms, possibly by preventing the decrease in dopamine and BDNF expression. Thus, BA may be a useful agent for the treatment or alleviation of the complex symptoms associated with depression.

Hemoglobin Concentration in Female Workers of Occupational Exposure to Lead (연 취급 근로자들의 혈색소치의 변동)

  • Park, Nan-Kyu;Kang, Pock-Soo;Chung, Jong-Hak
    • Journal of Yeungnam Medical Science
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    • v.3 no.1
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    • pp.73-79
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    • 1986
  • This study was conducted to evaluate the effects of lead on the incidence of anemia and to find cases with lead poisoning early among female workers who have been exposed to lead occupationally, for one year from August, 1985. The level of blood lead and hemoglobin concentration were observed for 284 female lead workers and 123 female non-lead workers of industries in the Gumi industrial complex in Kyungpook Province. The average age was $20.3{\pm}2.9$years and $21.1{\pm}3.5$ years in lead workers and non-lead workers, respectively. The average working duration was $26.46{\pm}19.26$ months in lead workers. The mean value of blood lead was $30.11{\pm}6.61{\mu}g/100ml$ and $21.86{\pm}3.75{\mu}g/100ml$ in lead workers and non-lead workers, respectively. There were significant differences between two groups. The mean value of hemoglobin concentration was $14.00{\pm}0.57g/100ml$ and $14.03{\pm}0.64g/100ml$ in lead workers and non-lead workers, respectively. Anemia cases were not observed at Hb concentration below 12g/100ml. The percentages of lead workers at Hb concentration ranged 12.0~13.0g/100ml were 4.5%. There was no dose-response relationship between blood lead level and the incidence of anemia. There were no remarkable differences between age and blood lead level as well as Hb concentration, and between working duration and the level of blood lead and hemoglobin.

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Developing improvement technology in pre-etching process for the Shadow Mask quality of flat color TV

  • Park, Jong-Moo;Park, Kwang-Ho;Jung, Hyo-Jin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.1164-1167
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    • 2003
  • Recently CRT is getting flatted, As change of CRT trend from normal type to Flat type, the material of Shadow Mask was also changed from AK(Aluminum Killed) to Invar(Fe-Ni alloy) materials Until now we have used just AK(Aluminum Killed) for normal type TV(not flat type), but main raw material of shadow mask component was changed. . However recently Invar(Fe-Ni alloy) materials, which has advantage of Low Thermal Expansion and High Strength, has been developed as well as applying in mass production as CRT's trend has become more flat and fine pitch. As main raw material of shadow mask component was changed, conditions of process were changed. One of them, the importance of pre-etching process (assistant process for developing & etching) is improved because there are so many particles in the pre-etching bath because of Ni compounds. Since the solubility of Ni in pre-etching solvent is very low related to Fe's, so the compounds of Ni happen to make particles.(the solubility of Fe is twenty times Ni's) that particles happen to make process troubles and NG productions so to clear the particles we had to established high cost filtering system, but it is useless. As time goes by the quantity of particles (Ni compounds) was increased because of the capability of filtering system was not enough, the particles was produced continuous in bath, and it make quality problems. Hence we tried to develop the new pre-etching solution to remove the particles (Ni compounds) and to cost down the filtering system's running cost. But in improving the solution we discovered the new pre-etching solution made the PR developing better. In former solution there were three kinds of chemistry (COOH)2 , H2O2 , H2S04 .first the function of (COOH)2 is drilling the surface of Invar, during this mechanism Ni compounds occurred. Second the function of H202 is removing the PR fringe (half UV exposure zone on PR(PVA)), Third the function of H2S04 is the catalysis of (COOH)2 In those, (COOH)2 was the main reason to make the Ni compounds. So to improve the solutions we had to change (COOH)2 to the other material. the chemistry we improved was a complex chemistry based on H2S04 . after using this chemistry the particles problem was disappeared and there was another advantage cut down the PR fringe. The New solution made the function of H202 better so the PR developing improved. To be direct the catalyst of the new solution helped the H202. anyway First thing after change the solution the quality of shadow Mask for flat color TV was improved & the yield also improved. But the more important thing is how to control the new solution. So we accepted the new concept which was the degree of freshness. The degree of freshness is based on non-reacted solution which was 100% ( the degree of freshness) and calculated the melted Ni quantity as time goes by. So we made the gauging liner plot. In conclusion, many companies tried to make fine pitched Shadow Mask ,generally to make quality jump up it needed a lot of cost & persons .in this case the shift of core material made it possible.

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