• Journal of Environmental Science International
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• v.27 no.11
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• pp.947-956
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• 2018

Trains have been a major means of transport in Korea during these past decades. However, train facilities such as stations and repair shops are contaminated with organic and inorganic substances. There is a high probability of train facility contamination with polyaromatic hydrocarbons (PAHs). This study evaluated the PAH and heavy metal contamination of soil near railroads in the Kyungpook area. A total of 18 soil samples were collected from the railroads and analyzed for 16 PAHs and 6 heavy metal species. The contamination level of the top soil was found to be slightly higher than that of the subsoil for contamination with PAHs. The ratio of carcinogenic PAH concentration to the total PAH concentration was relatively high, with a maximum of 0.9. The toxicity equivalent (TEQ) of the PAHs were 500.6 ng/kg in the topsoil and 355.5 ng/kg in the subsoil. The ratio of low molecular PAHs (LPAHs) to high molecular PAHs (LPAHs) ranged from 6.7 to 29.5; this shows that contamination is primarily due to combustion of fuel rather than due to petroleum. The ratio of phenanthrene to anthracene and the ratio of fluoranthene to pyrene also show that contamination occurred due to combustion for transportation. The heavy metal contamination level was lower than the Korean standard, but higher than the background concentration; this indicates that the soil was affected by the operation of the railways.

• Economic and Environmental Geology
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• v.55 no.1
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• pp.19-27
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• 2022

Fish that inhabited in the watersheds of Andong, Imha and Yeongju Dam in the upper Nakdong River were analyzed heavy metals by separated into muscle, gill, stomach and liver part. Thirteen fish species such as dark chub, skygager, coreoperca herzi, Korean piscivorous chub, cornet fish, Japan crucian carp, catfish, bass, crucian carp, mandarin fish, carp, long-nosed barbel, Korean sharpbelly were analyzed using ICP/MS. The results of the analysis based on the overall average concentration showed that the muscle part is lower than other parts in all heavy metal items except mercury. The gill part showed high concentrations of chromium, manganese, nickel, and lead, the stomach part has high zinc, and the liver part showed high concentrations of iron, copper, arsenic, and cadmium.

• Proceedings of the Korean Magnetic Resonance Society Conference
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• 2002.08a
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• pp.72-72
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• 2002

In most traditional sorption study in environmental conditions, experimental sorption data have been measured and interpreted by empirical ways such as partition coefficient and sorption isotherms. A mechanistic understanding of heavy metal interactions with various minerals (metal oxides, clay minerals) in aqueous medium is required to describe the behavior of radioactive metal ions in the environment. Various spectroscopic methods provide direct or indirect information on sorption mechanisms involved. We applied EPR (Electron Paramagnetic Resonance) spectroscopy to investigate the nature of metal ion sorption at water/mineral interfaces using Cu(II) as a spin probe. The major sorbed species and their motional state was identified by their EPR spectra. They showed distinct signals due to their strength of binding, local structure and motional state. The EPR results together with macroscopic sorption data show that sorption involved at least three different mechanisms depending on chemical environments (1).

• Journal of the Korean earth science society
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• v.24 no.7
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• pp.635-649
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• 2003

Heavy metal concentrations and benthic foraminiferal distributions were investigated in three short sediment cores in order to understand the pollution history in Masan Bay. Sedimentation rates were 0.33 cm/yr, 0.20 cm/yr and 0.33 cm/yr in the inner bay, the out fall of Dugdong sewage disposal plant, and bay mouth, respectively. The rapid increases of copper, zinc and lead concentrations at the core depth of 10 cm the upper part indicated that Masan Bay has been polluted with industrial wastes since the 1940s. Benthic foraminifera in core sediments show that the variations in their distribution were followed by industrial pollution in the bay. The number of individuals and species diversity decreased, whereas agglutinated tests increased upward in the cores with increased heavy metal pollution. These shifts effectd the abundance of few tolerant forms and consequently decreased the species diversity. The opportunistic species Eggerella advena and Trochammina pacifica increased in polluted sediments. These species can be used as an indicator for assessments of environmental quality in Masan Bay.

• Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.21.1-21.11
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• 2016

Background: The evaluation of suitable reference genes as normalization controls is a prerequisite requirement for launching quantitative reverse transcription-PCR (RT-qPCR)-based expression study. In order to select the stable reference genes in abalone Haliotis discus hannai tissues (gill and hepatopancreas) under heavy metal exposure conditions (Cu, Zn, and Cd), 12 potential candidate housekeeping genes were subjected to expression stability based on the comprehensive ranking while integrating four different statistical algorithms (geNorm, NormFinder, BestKeeper, and ${\Delta}CT$ method). Results: Expression stability in the gill subset was determined as RPL7 > RPL8 > ACTB > RPL3 > PPIB > RPL7A > EF1A > RPL4 > GAPDH > RPL5 > UBE2 > B-TU. On the other hand, the ranking in the subset for hepatopancreas was RPL7 > RPL3 > RPL8 > ACTB > RPL4 > EF1A > RPL5 > RPL7A > B-TU > UBE2 > PPIB > GAPDH. The pairwise variation assessed by the geNorm program indicates that two reference genes could be sufficient for accurate normalization in both gill and hepatopancreas subsets. Overall, both gill and hepatopancreas subsets recommended ribosomal protein genes (particularly RPL7) as stable references, whereas traditional housekeepers such as ${\beta}-tubulin$ (B-TU) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were ranked as unstable genes. The validation of reference gene selection was confirmed with the quantitative assay of MT transcripts. Conclusions: The present analysis showed the importance of validating reference genes with multiple algorithmic approaches to select genes that are truly stable. Our results indicate that expression stability of a given reference gene could not always have consensus across tissue types. The data from this study could be a good guide for the future design of RT-qPCR studies with respect to metal regulation/detoxification and other related physiologies in this abalone species.

• Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.179-184
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• 2009

Hemibarbus mylodon (Cypriniformes) is an endemic freshwater fish species in the Korean peninsula, for which urgent conservation efforts are needed. To understand their stress responses in relation to metal toxicity and thermal elevation, we performed a real-time RT-PCR-based expression assay of hepatic copper/zinc-superoxide dismutase (Cu/Zn-SOD), a key antioxidant enzyme, in response to experimental heavy metal exposure or heat treatment. The transcription of hepatic Cu/Zn-SOD was differentially modulated by acute exposure to Cu, cadmium (Cd), or Zn. Exposure to each metal at $5{\mu}M$ for 24 h revealed that Cu stimulated the mRNA expression of Cu/Zn-SOD to a greater extent than the other two heavy metals. The elevation in Cu/Zn-SOD transcripts in response to Cu exposure was dose-dependent (0.5 to $5{\mu}M$). Time course analysis of Cu/Zn-SOD expression in response to Cd exposure ($5{\mu}M$) revealed a transient pattern up to day 7. Exposure to thermal stress (an increase from 22 to $30^{\circ}C$ at a rate of $1^{\circ}C/h$ followed by $30^{\circ}C$ for 18 h) did not significantly alter SOD transcription, although heat shock protein 90 kDa (HSP90) transcription was positively correlated with an increase in temperature.

• Journal of Soil and Groundwater Environment
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• v.12 no.4
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• pp.72-77
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• 2007

Soil contamination by heavy metals was environmental concern due to its effect on human. In this study, monopotassium phosphate $(KH_2PO_4)$ used as phosphate source to remediate the contaminated soil with heavy metals and factors such as reaction time, initial concentration and pH of phosphate solution, species of heavy metal (lead, cadmium, zinc) and particle size were controlled. Heavy metals were removed in the order Pb > Zn > Cd and the maximum effectiveness was achieved for Pb. The removal efficiency of lead was from 95% to 100% and occurred rapidly occurred during 10 minutes. Mechanism of lead immobilization is dissolution of phosphate and the forming of a new mineral with phosphate having extremely low solubility.

• Journal of Environmental Impact Assessment
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• v.24 no.6
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• pp.561-577
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• 2015

The heavy metal accumulations of avian eggshells were studied in order to test a feral pigeon (Columba livia)'s eggshell as an indicator for the environmental monitoring of pollutants. The reviews on the eggs of the different 19 avian species showed that it is the eggshell rather than the egg content that can better reflect the heavy metals in the environment; in most cases the CVs (coefficients of variations) of the heavy metal concentrations in the eggshells were higher than those in the egg contents. This can indicate that the heavy metal accumulations are homeostatically controlled in the egg contents, but the accumulations in the eggshells are varied according to the environmental conditions. To test the reviews, the feral pigeon eggs from the two different sites, one representing urban and the other rural environment, were analyzed for lead (Pb) and cadmium (Cd). The result showed that the eggshells of the urban pigeons (Hangang) had the higher metal concentrations than those of the rural pigeons (Hampyeong). The same difference can also be found in the internal organs (liver, bone) and blood. However, the analyses of the egg contents between the two sites did not reveal the differences. In other words, the result suggests that the feral pigeons, like the other avian species, are able to control the heavy metals into the egg contents homeostatically. Therefore, it is more useful to use the feral pigeon eggshell rather than the egg content in case of monitoring heavy metals in different habitats.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.98-105
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• 2005

The relative sensitivity of two freshwater non- biting midges, Chironomus yoshimatsui Martin and Sublette and C. riparius Meigan, was examined for lead, cadmium, and mercury in water- only exposures. Two endpoints were compared to assess toxicity 48 h and 96 h after exposure: Acute toxicity ($50\%$ lethal concentration: $LC_50$) and behavioral toxicity ($50\%$ effective concentration: $EC_{50}$). for the behavioral toxicity, reduction of swimming performance of two midge species in the treated conditions was compared to that in the untreated control. The sensitivities differed depending on the species and heavy metals, although some trends emerged. $LC_50$ values in C. yoshimatsui to cadmium and lead were always higher than those in C. riparius with increasing toxicity, regardless of the exposure times. The opposit was true for the mercury treatment. Similar trends were observed in the $EC_{50}$ values. The $EC_{50}$ values were always lower than the $LC_50$ values in all the treatment cases (midge species, heavy metals, and exposure times). These results indicate that the two midge species respond to the heavy metals differently: C. riparius is sensive to cadmium and lead and C. yoshimatsui to mercury. Behavioral toxicity such as swimming performance can be an effective endpoint for assessing heavy metal toxicity in water.

• Animal cells and systems
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• v.7 no.3
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• pp.173-186
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• 2003

The transition metal cadmium is a serious occupational and environmental toxin. To inhibit cadmium-induced damage, cells respond by increasing the expression of genes that encode stress-responsive proteins. The metal-regulatory transcription factor 1 (MTF-1) is a key regulator of heavy-metal induced transcription of metallothionein-I and II and other genes in mammals and other metazoans. Transcriptional activation of genes by MTF-1 is mediated through binding to metal-responsive elements in the target gene promoters. Phosphorylation of MTF-1 plays a critical role in the cadmium-inducible transcriptional activation of metallothionein and other responses. Studies using inhibitors indicate that multiple kinases and signal transduction cascades, including those mediated by protein kinase C, tyrosine kinase and casein kinase II, are essential for cadmium-mediated transcriptional activation. In addition, calcium signaling is also involved in regulating metal-activated transcription. In several species, cadmium induces heat shock genes. Recently much progress has been made in elucidating the cellular machinery that regulates this metal-inducible gene expression. This review summarizes these recent advances in understanding the role of some known cadmium-responsive genes and the molecular mechanisms that activate metal-responsive transcription factor, MTF-1.