• Journal of Korean Society for Atmospheric Environment
• /
• v.8 no.2
• /
• pp.100-104
• /
• 1992

The research in this paper centers on a comparative risk assessment for nearby air pollution by carcinogenic metal emission from municipal solid waste incinerators. If a substance is identified as a potential human carcinogen, the carcinogenicity may be related to the chemical form of a substance and the route of exposure. This type of information with regard to carcinogenic uncertainty is incorporated into hazard quantification. In addition to the dioxin emission, the metal emission from municipal solid waste incineration is found to be a major contributor to human cancer risk via the inhalation route. The magnitude of risk by metals is about 5 times greater than that of risk by dioxins. Hexavalent form of chromium and cadmium compounds are major contributors to cancer risk from metal emission. In addition, hexavalent chromium is known to be human carcinogen while 2,3,7,8-TCDD is known to be only probable human carcinogen.

• Journal of Ginseng Research
• /
• v.32 no.2
• /
• pp.114-119
• /
• 2008

Terpene synthase plays a key role in biosynthesis of triterpene saponins (ginsenosides) and is intermediate in the biosynthesis of a number of secondary metabolites. A terpene synthase (PgTPS) cDNA was isolated and characterized from the root of Panax ginseng c.A. Meyer. The deduced amino acid sequence of PgTPS showed a similarity with A. deliciosa (AAX16121) 61%, V. vinifera (AAS66357) 61%, L. hirsutum (AAG41891) 55%, M. truncatula (AAV36464) 52%. And the segment of a terpene synthase gene was amplified by reverse transcriptase-polymerase chain reaction (RTPCR). We studied expression of terpene synthase under stressful conditions like chilling, salt, UV, and heavy metal stress treatment. Expression of PgTPS was increased gradually after exposure to stresses such as chilling, salt, and UV illumination. But its transcription seems to be reduced by cadmium and copper treatment.

• Progress in Medical Physics
• /
• v.31 no.3
• /
• pp.81-98
• /
• 2020

This review aims to provide a brief, comprehensive overview of advanced technologies of nuclear medicine physics, with a focus on recent developments from both hardware and software perspectives. Developments in image acquisition/reconstruction, especially the time-of-flight and point spread function, have potential advantages in the image signal-to-noise ratio and spatial resolution. Modern detector materials and devices (including lutetium oxyorthosilicate, cadmium zinc tellurium, and silicon photomultiplier) as well as modern nuclear medicine imaging systems (including positron emission tomography [PET]/computerized tomography [CT], whole-body PET, PET/magnetic resonance [MR], and digital PET) enable not only high-quality digital image acquisition, but also subsequent image processing, including image reconstruction and post-reconstruction methods. Moreover, theranostics in nuclear medicine extend the usefulness of nuclear medicine physics far more than quantitative image-based diagnosis, playing a key role in personalized/precision medicine by raising the importance of internal radiation dosimetry in nuclear medicine. Now that deep-learning-based image processing can be incorporated in nuclear medicine image acquisition/processing, the aforementioned fields of nuclear medicine physics face the new era of Industry 4.0. Ongoing technological developments in nuclear medicine physics are leading to enhanced image quality and decreased radiation exposure as well as quantitative and personalized healthcare.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.3
• /
• pp.330-338
• /
• 2011

BACKGROUND: This study was conducted to investigate the agricultural product (Pulses, Lettuces, Pumpkins, Apples, Pears and Tangerines) in Korea, monitoring of cadmium (Cd) and lead (Pb) contaminations of agricultural products in cultivated areas and abandoned mine areas were investigated, and risk assessment was performed through dietary intake of agricultural products. METHODS AND RESULTS: The average contents of Cd and Pb ranged from 0.001 to 0.018 mg/kg and from 0.007 to 0.032 mg/kg respectively. The result was showed that contents of Cd and Pb did not exceed maximum residual levels established by CODEX except pumpkins and apples. The average daily intake were in the range of $1.06{\times}10^{-3}$ to $4.76{\times}10^{-2}{\mu}g/kg$ b.w./day at the mean and 95th percentile for Cd, $4.53{\times}10^{-3}$ to $8.35{\times}10^{-2}{\mu}g/kg$ b.w./day at the mean and 95th percentile for Pb for general population, based on the Korean public nutrition report 2008. The Hazard Index (HI) from the ratio analysis between daily exposure and safety level values was smaller than 1.0. CONCLUSION(s): This results demonstrated that human exposure to Cd and Pb through dietary intake of agricultural produces from abandoned mine areas might not cause adverse effect exceeding to those from non-contaminated areas.

• Journal of Life Science
• /
• v.29 no.2
• /
• pp.265-271
• /
• 2019

In general, specific gravity (SG) and urinary creatinine (CR) have been used to adjust urinary cadmium (Cd) concentrations. However, the validity of correction methods has been controversial. We compared the two adjustments to evaluate associations between urinary Cd and various renal damage markers and to evaluate the relationship between urinary Cd concentration and renal disease markers, such as estimated glomerular filtration rate (eGFR), in a relatively large general population sample. Among the 1,086 volunteers who were enrolled in this study, 862 healthy volunteers who did not have kidney disease were included in the final analysis. Urinary Cd, malondialdehyde (MDA), and N-acetyl-${\beta}$-D-glucosaminidase (NAG) concentrations were measured, the creatinine-based eGFR was calculated, and the relationships between these markers were subsequently analyzed. This study showed the use of urinary Cd concentration adjusted with SG rather than with urinary creatinine may be appropriate in studies evaluating renal function based on Cd exposure. Urinary Cd concentration adjusted with SG had a positive correlation with urinary MDA levels and a negative correlation with eGFR. This relationship was relatively stronger in women than in men. This study showed that urinary Cd level was associated with decreased eGFR in the general population, and oxidative stress was likely to act as an intermediator in this process. These results suggest that eGFR can be a very good indicator of kidney damage caused by Cd exposure in the general population.

• Food Science of Animal Resources
• /
• v.33 no.5
• /
• pp.617-625
• /
• 2013

The present study was carried out to assess dietary exposure and risk for the infant population by lead (Pb), cadmium (Cd), and arsenic (As) exposure through modified milk powder and formulas. Analysis of heavy metals was performed using a microwave device and inductively coupled plasma-mass spectrometry, the method for which was fully validated. Various samples (n=204), including modified milk powder, modified milk, follow-up modified milk powder, infant formula and follow- up formula, were collected from retail outlets and markets across Korea. The mean contents of heavy metals were Pb 0.0004 (modified milk)-0.010 (infant formula) mg/kg, Cd 0.002 (modified milk)-0.007 (follow-up formula) mg/kg, and As 0.004(modified milk)-0.040 (infant formula) mg/kg, respectively. For risk assessment, daily intakes of heavy metals through maximum intake of modified milk powder and formulas were calculated and compared with reference doses established by JECFA and WHO. The dietary exposures of heavy metals were $0.78-1.04{\mu}g$ Pb/d, $0.65-0.87{\mu}g$ Cd/d, and $2.25-3.00{\mu}g$ As/d, corresponding to 2.0-4.5%, 7.1-16.0%, and 0.4-0.9% of reference doses, respectively. Therefore, the level of overall dietary exposure to heavy metals for Korean infant through food intake was below 20% of the reference dose, indicating a low risk to infant consumers.

• Journal of Environmental Health Sciences
• /
• v.48 no.4
• /
• pp.236-243
• /
• 2022

Background: In the case of multiple exposures to different types of heavy metals, such as the conditions faced by residents living near a smelter, it would be preferable to group hazardous substances with similar characteristics rather than individually related substances and evaluate the effects of each group on the human body. Objectives: The purpose of this study is to evaluate the utility of factor analysis in the assessment of health effects caused by exposure to two or more hazardous substances with similar characteristics, such as in the case of residents living near a smelter. Methods: Heavy metal concentration data for 572 people living in the vicinity of the Janghang smelter area were grouped based on several subfactors according to their characteristics using factor analysis. Using these factor scores as an independent variable, multiple regression analysis was performed on health effect markers. Results: Through factor analysis, three subfactors were extracted. Factor 1 contained copper and zinc in serum and revealed a common characteristic of the enzyme co-factor in the human body. Factor 2 involved urinary cadmium and arsenic, which are harmful metals related to kidney damage. Factor 3 encompassed blood mercury and lead, which are classified as related to cardiovascular disease. As a result of multiple linear regression analysis, it was found that using the factor index derived through factor analysis as an independent variable is more advantageous in assessing the relevance to health effects than when analyzing the two heavy metals by including them in a single regression model. Conclusions: The results of this study suggest that regression analysis linked with factor analysis is a good alternative in that it can simultaneously identify the effects of heavy metals with similar properties while overcoming multicollinearity that may occur in environmental epidemiologic studies on exposure to various types of heavy metals.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.13 no.4
• /
• pp.288-295
• /
• 2010

Metal exposure experiments using polychaete (Perinereis nuntia) as a bio-indicator of trace metals contamination were conducted to evaluate the bioaccumulation and the biomarkers responses such as metallothionein-like protein (MTLPs) and glutathione S-transferase (GST) which was simultaneously exposed to Cadmium (Cd) and Copper (Cu). Cu and Cd concentrations in polychaete were enhanced with increasing exposure time and their concentrations of aqueous medium. Initial accumulation of Cd was higher than that of Cu. Our results showed that the bioaccumulation of Cu and Cd were prohibited, especially at higher Cu levels, suggesting the different cellular uptake mechanisms when Cu and Cd are co-exist. Net accumulation rate of Cu was declined with exposure time but it did not show any significant change for Cd. Although the highest MTLPs concentration was observed at 6 hr of exposure time, it did not show any significant change related to exposure times and metals concentrations. An increase of GST activity tended to increase as a function of exposure time and metals concentrations. And GST activities in P. nuntia have similar tendency with bioconcentration factors in high concentration of Cu (treatment group IV) at post 24 h of exposure. Our results provide new information of the bioaccumulation and biomarker responses to understand the effects of co-existing contaminants (Cu and Cd) using polychaete. Further studies are required to elucidate the bioaccumulation and biomarkers responses for various contaminants.

• Journal of Nutrition and Health
• /
• v.44 no.1
• /
• pp.61-73
• /
• 2011

The aim of this study was to develop a reliable dietary questionnaire to assess human exposure to food-borne hazards. Eleven food-borne hazards were chosen as a priority control list through a literature review and advisory committees. The 11 food-borne hazards were phthalate, aflatoxin, bisphenol A, polycyclic aromatic hydrocarbons, dioxin, polychlorinated biphenyls, mercury, lead, cadmium, arsenic, and acrylamide. The characteristics, exposure level, and paths of these hazards were reviewed, and questionnaire items were identified to assess human exposure from the literature. A questionnaire was developed for each selected food based on its characteristics. Based on the items in the individual questionnaires, a comprehensive questionnaire, which contained demographic characteristics, job information, socioeconomic factors, health related lifestyles, and dietary behaviors, was developed. A 99-item food frequency questionnaire (FFQ) to assess food-borne hazard exposure was also developed. The FFQ included frequency of food intake during the previous year, container type for purchasing and storing food, and cooking method. The questionnaire developed in this study could be applied to assess dietary factors during an exposure assessment of food-borne hazards in a large population. A validation study for the questionnaire is needed before applying it to surveys.

• The Korean Journal of Malacology
• /
• v.30 no.1
• /
• pp.41-49
• /
• 2014

This study was conducted to investigate the effects of cadmium (Cd) exposure on biochemical factors in the hemolymph and hepatopancreas of the abalone, Haliotis discus hannai. The abalone were exposed to 0, 5, 10, 20 and 40 ${\mu}g/L$ Cd for 4 weeks. The phenoloxidase (PO) activity was decreased in hemolymph of abalone exposed to 40 Cd ${\mu}g/L$ for 4 weeks compared to the control (P < 0.05). The hemolymph enzymes, alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were markedly elevated in 40 Cd ${\mu}g/L$ after 4 weeks. The hemolymph calcium concentrations were significantly decreased in 20 and 40 Cd ${\mu}g/L$ for 4 weeks. Hepatopancreas superoxide dismutase (SOD) and catalase (CAT) activities were significantly increased by Cd. SOD was increased in both 20 and 40 Cd ${\mu}g/L$ and CAT, in 40 Cd ${\mu}g/L$ after 2 weeks (P < 0.05). These results suggested that the abalone SOD and CAT including PO may serve as a protective mechanism against oxidative stress by Cd. We conclude that a Cd concentration, 40 ${\mu}g/L$ in water may curtail hemolymph homeostasis and anti-oxidative reactions in abalone hepatopancreas. From these results, these biochemical factors may represent a convenient method of monitoring heavy metal pollution in coastal areas.