• Title, Summary, Keyword: Zn assessment

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Fate and Bioaccumulation of Zinc Oxide Nanoparticles in a Microcosm (산화아연 나노물질의 미소생태계 내 거동 및 생물축적)

  • Kim, Eunjeong;Lee, Jae-woo;Jo, Eunhye;Sung, Hwa Kyung;Yoo, Sun Kyoung;Kim, Kyung-tae;Shin, Yu-jin;Kim, Ji-eun;Park, Sun-Young;Eom, Ig-chun;Kim, Pilje
    • Journal of Environmental Health Sciences
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    • v.43 no.3
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    • pp.194-201
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    • 2017
  • Objectives: Zinc oxide nanoparticles (ZnO NPs) are widely used in various commercial products, but they are exposed to the environment and can induce toxicity. In this study, we investigated the environmental fate and bioaccumulation of ZnO NPs in a microcosm. Methods: The microcosm was composed of water, soil (Lufa Soil 2.2) and organisms (Oryzias latipes, Neocaridina denticulata, Semisulcospira libertina). Point five and 5 mg/L of ZnO NPs were exposed in the microcosm for 14 days. Total Zn concentrations were measured using an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and intracellular NPs were observed using Transmission Electron Microscopy (TEM). Results: In the initial stages of exposure, the Zn concentrations in water increased in all exposure groups and then decreased, while the Zn concentration in soil increased after three hours for the 5 mg/L solution. Zn concentrations also showed increasing trends in N. denticulata and S. libertina at 0.5 and 5 mg/L, and in O. latipes at 5 mg/L. Accumulation of NPs was found in the livers of O. latipes and hepatopancreas of N. denticulata and S. libertina. Conclusions: In the early stages of exposure, ZnO NPs remained in the water, and then were transported to the soil and test species. Unlike other species, total Zn concentrations in N. denticulata and S. libertina increased for both 0.5 mg/L and 5 mg/L. Therefore, ZnO NPs were more easily accumulated in zoobenthos than in fish.

Zinc Status Assessment by Analysis of Mononuclear Cell Metallothionein mRNA Using Competitive-Reverse Transcriptase-Polymerase Chain Reaction

  • Lee, Soo-Lim;Yoon, Jin-Sook;Kwon, Chong-Suk;Beattie, John H.;Kwun, In-Sook
    • Preventive Nutrition and Food Science
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    • v.9 no.3
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    • pp.276-282
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    • 2004
  • Marginal Zn deficiency is prevalent through the world and yet human zinc status has not been properly assessed due to the lack of a reliable diagnostic indicator. One potential possibility for zinc status assessment using Zn-binding protein, metallothionein (MT)-mRNA, has been proposed. The purpose of the present study was aimed to show whether measurement of mononuclear cell (MNC) MT mRNA, using a competitive-reverse transcriptase-polymerase chain reaction (competitive-RT-PCR) assay, could indicate zinc status in human subjects. In this study, MNC MT-mRNA expression was measured using a competitive-RT-PCR to compare before and after 14 days of zinc supplementation (50 mg Zn/das zinc gluconate). RT-PCR oligonucleotide primers which were designed to amplify both a 278 bp segment of the human MT-2A cDNA and a 198 bp mutant competitor cDNA template from MNCs, were prepared. MT-2A mRNA was normalized by reference to the housekeeping gene, $\beta$-actin, mRNA for which was also measured by competitive-RT-PCR. There was considerable inter-individual variation in MT-mRNA concentration and yet, the mean MT-2A mRNA level increased 4.7-fold after Zn supplementation, as compared to before Zn supplementation. This MT-2A mRNA level was shown as the same pattern and, even more sensitive assay, compared to the conventional plasma and red blood cells (RBCs) Zn assessment in which plasma and RBCs zinc levels increased 2.3- and 1.2-fold, respectively (p<0.05). We suggest that MT competitive-RT-PCR can be a useful assessment tool for evaluating human zinc status.

Thermoelectric Properties of ZnkIn2O3+k(k=1∼9) Homologous Oxides (Homologous 산화물 ZnkIn2O3+k(k=1∼9)의 열전 특성)

  • Nam, Yun-Sun;Choi, Joung-Kyu;Hong, Jeong-Oh;Lee, Young-Ho;Lee, Myung-Hyun;Seo, Won-Seon
    • Korean Journal of Materials Research
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    • v.13 no.8
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    • pp.543-549
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    • 2003
  • In order to investigate the thermoelectric properties of $Zn_{k}$ $In_2$$O_{ 3+k}$ homologous compounds, the samples of $Zn_{k}$ /$In_2$$O_{3+k}$ / (k = integer between 1 and 9) were prepared by calcining the mixed powders of ZnO and $In_2$$O_3$fellowed by sintering at 1823 K for 2 hours in air, and their electrical conductivities and Seebeck coefficients were measured as a function of temperature in the range of 500 K to 1150 K. X-ray diffraction analysis of the sintered samples clarified that single-phase specimens were obtained for $Zn_{k} /$In_2$$O_{3+k}$ with k = 3, 4, 5, 7, 8, 9. Electrical conductivity of the $Zn_{k}$ $In_2$$O_{3+k}$ / decreased with increasing temperature, and decreased with increasing k for k $\geq$ 3. The Seebeck coefficient was negative at all the temperatures for all compositions, confirming that $Zn_{k}$ $In_2$$O_{3+k}$ / is an n-type semiconductor. Absolute values of the Seebeck coefficient increased linearly with increasing temperature and increased with increasing k for k $\geq$ 3. The temperature dependence of the Seebeck coefficient indicated that Z $n_{k}$I $n_2$ $O_{3+k}$ could be treated as an extrinsic degenerate semiconductor. Figure-of-merits of Z $n_{k}$I $n_2$ $O_{3+k}$ were evaluated from the measured electrical conductivity and Seebeck coefficient, and the reported thermal conductivity. Z $n_{7}$ I $n_2$ $O_{10}$ has the largest figure-of-merit over all the temperatures, and its highest value was $1.5{\times}$10$^{-4}$ $K^{-1}$ at 1145 K.5 K.

Toxic Effects of Heavy Metal (Cd, Cu, Zn) on Population Growth Rate of the Marine Diatom (Skeletonema costatum) (중금속(Cd, Cu, Zn)이 해산규조류(Skeletonema costatum)의 개체군 성장률에 미치는 독성영향)

  • Hwang, Un-Ki;Ryu, Hyang-Mi;Lee, Ju-Wook;Lee, Seung-Min;Kang, Han Seung
    • Korean Journal of Environmental Biology
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    • v.32 no.3
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    • pp.243-249
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    • 2014
  • In this study, we evaluated the toxic effects of heavy metals (Cd, Cu, Zn) on the population growth rate (r) of the marine diatom, Skeletonema costatum. S. costatum. The population growth rate (r) of the species was determined after 96 hrs. of exposure to Cd (0, 0.63, 1.25, 2.50, 5.00, 10.00 ppm), Cu (0, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50 ppm) and Zn (0, 0.31, 0.63, 1.25, 2.00, 2.50, 5.00 ppm). It was observed that 'r' in the control (absence of Cd, Cu and Zn) were greater than 0.05, however suddenly decreased with increased heavy metal concentrations. Cd, Cu and Zn reduced 'r' in a dose-dependent manner and a significant reduction were occurred at concentration of greater than 1.25, 1.25 and 2.50 ppm, respectively. Based on the toxicity, the heavy metal were ranked as Cu>Zn>Cd, with EC50 values of 1.11, 2.13 and 6.84 ppm, respectively. The lowest-observed-effective-concentration (LOEC) of 'r' in exposed to Cd, Cu and Zn were 1.25, 1.00, 2.00 ppm, respectively. Precisely, a concentration of greater than 1.25 ppm of Cd, 1.00 ppm of Cu and 2.00 ppm of Zn in marine ecosystems induced toxic effect on the 'r' of S. costatum. Based on our results, we suggested that the 'r' of S. costatum might be a useful bio indicator for the toxicity assessment of heavy metals in marine ecosystems.

Effect of Heavy Metals on the Survival and Population Growth Rates of Marine Rotifer, Brachionus plicatilis (중금속(Cd, Cu, Zn) 농도구배에 따른 윤충류 Brachionus plicatilis의 생존 및 개체군 성장에 미치는 영향)

  • Hwang, Un-Ki;Ryu, Hyang-Mi;Heo, Seung;Chang, Soo-Jung;Lee, Ki-Won;Lee, Ju-Wook
    • Korean Journal of Environmental Biology
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    • v.34 no.4
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    • pp.353-360
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    • 2016
  • Effect of heavy metals(Cd, Cu, Zn) on the survival and population growth rates(PGR) of marine rotifer, Brachionus plicatilis were examined. B. plicatilis were exposed to Cd, Cu and Zn for 24 h to determine their survival and 72 h to determine their PGR. Survival rates in the control groups were greater than 90%. They were decreased with increasing concentrations of Cd, Cu and Zn. Survival rates were reduced in a concentration-dependent manner. Significant reduction in survival rates after exposure to Cd, Cu and Zn at concentration greater than 40.00, 0.13 and $10.00mg\;L^{-1}$, respectively. PGR in the control groups were greater than 0.50. They were decreased with increasing concentrations of heavy metals. PGR were reduced in a concentration-dependent manner. Significant reduction in PGR after exposure to Cd, Cu and Zn occurred at concentration greater than 12.5, 0.06 and $1.00mg\;L^{-1}$, respectively. The order of heavy metal toxicity based on PGR was Cu>Zn>Cd, with $EC_{50}$ (50% Effective Concentration) values of 0.12, 6.15 and $21.41mg\;L^{-1}$, respectively. The lowest-observed-effective-concentrations(LOEC) of PGR after exposure to Cd, Cu and Zn were 12.50, 0.06 and $1.00mg\;L^{-1}$, respectively. The No-observed-effective-concentrations(NOEC) of PGR after exposure to Cd, Cu and Zn were 6.25, 0.03 and $0.01mg\;L^{-1}$, respectively, in marine ecosystems have toxic effects on PGR of B. plicatilis. These results suggest that the PGR of B. plicatilis are useful tool to assess the effect of heavy metals on primary consumers in marine natural ecosystems.

Human Risk Assessment of Soil Contaminated with Heavy Metal by Waste Reclaimed in Railway Maintenance Site (철도정비부지 내 매립된 폐기물에 의해 중금속으로 오염된 토양의 인체위해성 평가)

  • Braatz, Hatsue Minato;Jung, Minjung;Moon, Seheum;Park, Jinkyu
    • Journal of the Korea Organic Resources Recycling Association
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    • v.27 no.3
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    • pp.63-74
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    • 2019
  • This study carried out a human risk assessment of Cu, Pb, Zn and Ni contained in soil contaminated by improperly buried heavy metal wastes in railway sites. The purpose of the human risk assessment is to derive the need for soil remediation and factors that should be considered during soil remediation. Risk assessment was performed in accordance with the Environment Ministry's Risk Assessment Guidelines. The results of the human risk assessment of contaminated heavy metal soil contaminated by improperly buried waste in the railway site were presented after the process of determining exposure concentration, calculating exposure, and determining carcinogenic hazards. The heavy metal content of soil is 621.3 Cu mg/kg, 2,824.5 Pb mg/kg, 1,559.1 Zn mg/kg and 45 Ni mg/kg, which is the exposure concentration of the target contaminant. The results of human exposure according to exposure pathways were high in the order of soil outdoor dust >soil ingestion >soil contact, and Pb >Zn >Cu >Ni were higher in order of contaminant. The carcinogenic and noncarcinogenic risks of soil contaminated with heavy metal waste were higher than the allowable carcinogenic risks (TCR> $10^{-6}$) and the risk index (Hi < 1.0) suggested by USEPA. Therefore, the site needs to be remediated.

Heavy Metal Contents and Food Safety Assessment of Processed Seaweeds and Cultured Lavers (국내 가공 해조류와 미가공 김의 중금속 함량 및 식품 안전성평가)

  • Yang, Won Ho;Lee, Hyo Jin;Lee, Sang Yong;Kim, Seong Gil;Kim, Gi Beum
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.19 no.3
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    • pp.203-210
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    • 2016
  • In this study, nine heavy metals were analyzed in seaweeds collected from market and laver culture farm of Korea and a food safety assessment were also carried out for these heavy metals. The level of heavy metal concentrations in seaweeds was in the following order: Fe>As>Zn>Cu>Cd>Pb>Cr>Ni>Hg. Except for zinc and cadmium, seven heavy metals were significantly higher in cultured laver than in processed laver. Significant correlation was observed Cr-Fe in cultured laver and Cu-Zn, Cd-Cu, Cd-Zn and Pb-Ni in processed laver and Cu-Cr, Cu-Zn, Cd-Cr and Ni-Fe in sea tangle and Zn-Fe, Cr-Fe, Cr-Zn, Cd-Ni, Cu-Cd and Cu-Pb in processed sea mustard. Considering differences in heavy metal concentration between processed laver and cultured laver and in correlation among heavy metals, removal efficiency of heavy metals may be attributed to seaweed treatment process. The average weekly intakes of Cu, Cd, Zn, Fe and Hg via seaweeds consumption were about 0.1~7.6% of PTWI (Provisional Tolerable Weekly Intakes). Therefore, it was found that heavy metals in the seaweeds were very safe for consumption.

Acute Toxicity of Heavy Metal (Cd, Cu, Zn) on the Hatching Rates of Fertilized Eggs in the Olive Flounder (Paralichthys olivaceus) (넙치(Paralichthys olivaceus) 수정란 부화율에 대한 중금속(Cd, Cu, Zn)의 급성독성)

  • Hwang, Un-Ki;Ryu, Hyang-Mi;Kim, Seong-Gil;Park, Seung-Yoon;Kang, Han Seung
    • Korean Journal of Environmental Biology
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    • v.30 no.2
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    • pp.136-142
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    • 2012
  • Acute toxicity test of heavy metal (Cd, Cu, Zn) were examined using the hatching rates of fertilized eggs in the oliver flounder, Paralichthys olivaceus. Eggs were exposed to Cd, Cu, Zn (0, 10, 100, 500, 1000, 2500, 5000 ppb) and then normal hatching rates were investigated after 48 h. The normal hatching rates in the control condition (not including Cd, Cu and Zn) were greater than 80%, but suddenly decreased with increasing of heavy metal concentrations. Cd, Cu and Zn reduced the normal hatching rates in concentration-dependent way and a significant reduction occurred at concentration grater than 1000, 100, 100 ppb, respectively. The ranking of heavy metal toxicity was Zn>Cu>Cd, with $EC_{50}$ values of 584, 1015 and 1282 ppb, respectively. The no-observed-effect-concentration (NOEC) and the lowest-observed-effect-concentration (LOEC) showed each 100 and 500 ppb of normal hatching rates in exposed to Cu and Zn. The NOEC and LOEC of normal hatching rates in Cd were 500 ppb and 1000 ppb, respectively. From these results, the normal hatching rates of P. olivaceus have toxic effect at greater than the 100 ppb concentrations in Cu, Zn and the 500 ppb concentrations in Cd in natural ecosystems. These results suggest that biological assay using the normal hatching rates of P. olivaceus are very useful test method for the acute toxicity assessment of a toxic substance as heavy metal in marine ecosystems.

Risk Assessment for Heavy Metal Pollutants of Abandoned Mines Using Statistical Techniques (통계적 기법을 이용한 휴폐광산의 중금속 위해성 평가)

  • Dho, Hyon-Seung;Kim, Sung-Duk;Lee, Seung-Joo
    • Journal of the Korea Safety Management and Science
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    • v.11 no.3
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    • pp.41-48
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    • 2009
  • The risk assessment for heavy metal pollutions were analyzed by using statistical techniques including correlation and cluster analyses. The contamination data in this investigation obtained were from the Chungcheongnam-do abandoned mines. The descriptive statistical analysis showed that the values of Pb and Zn were relatively higher than other heavy metal values. The detection of heavy metals by distance from abandoned mines within 1,000m were mostly As, Cd, Pb, and Zn. It was noted, especially, that Zn was even detected at 4,000m The results of coefficient correlation showed that Zn to Cd was the highest values. The cluster and dendogram analyses were generated. The results showed the two clear groups by heavy metal characteristics.

Effects of Lead and Zinc on the Fertilization and Embryo Development of the Sea Urchin (Hemicentrotus pulcherrimus) (납과 아연이 말똥성게(Hemicentrotus pulcherrimus)의 수정 및 배아 발생에 미치는 영향)

  • Hwang, Un-Ki;Heo, Seung;Park, Jong-Soo;Kang, Han Seung
    • Korean Journal of Environmental Biology
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    • v.30 no.2
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    • pp.128-135
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    • 2012
  • The individual toxicity of lead (Pb) and zinc (Zn) has been investigated by using the sea urchin (Hemicentrotus pulcherrimus) germ cell and pluteus-larvae. The gametotoxic and embryotoxic effects of Pb and Zn on H. pulcherrimus were each investigated at 31, 63, 125, 250, 500 ppb and 16, 31, 63, 125, 250 ppb, respectively. Spawning was induced by 0.5 M KCl solution and the fertilization and normal embryogenesis rates test were performed for 10 min and 64 h after fertilization, respectively. In exposure to Pb, the fertilization rate was not significantly changed compared with control but normal embryogenesis rate was significantly decreased with concentration dependent manner. Fertilization and normal embryogenesis rates showed a significant decreased with concentration dependent manner in exposed to Zn. The normal embryogenesis rates were significantly inhibited in exposed to Pb ($EC_{50}$=45.13 ppb, 95% Cl=40.12~50.05 ppb) and Zn ($EC_{50}$=19.82 ppb, 95% Cl=18.26~21.31 ppb). In exposure to Pb and Zn, the NOEC of normal embryogenesis rate was <31.25 and <15.63 ppb, respectively. The LOEC showed each 31.25 and 15.63 ppb in exposed to Pb and Zn. These results suggest that the early embryo development of H. pulcherrimus is highly sensitive to heavy metals such as Pb and Zn, H. pulcherrimus can be used as a test organism for risk assessment in marine ecosystems.