Eunha Oh

Korea National Survey for Environmental Pollutants in the Human Body 2008: Heavy metals in the blood or urine of the Korean population

BACKGROUND Recently, there have been several nationwide episodes involving imported toys contaminated with toxic metals and environmental hormones. In addition, cadmium intoxication has occurred due to soil contamination with cadmium from abandoned metal mines. OBJECTIVES To investigate the distribution, extent and factors influencing the levels of toxic metals in the blood or urine of the Korean general population over twenty years of age, we studied the blood or urine concentrations of heavy metals in a representative sample of 5087 Koreans in 2008. METHODS Multiple biological substrates were collected from each participant to determine the most suitable samples for an environmental health survey system. Information regarding exposure conditions of all subjects was collected by questionnaire-based interviews. RESULTS The geometric means of the blood lead, mercury and manganese levels were 19.1, 3.23 and 10.8 μg/L, respectively. The geometric means of urinary arsenic and cadmium concentrations were 43.5 and 0.65 μg/L, respectively. Blood mercury and urinary arsenic levels in the Korean general population were significantly higher than in European and American populations. CONCLUSIONS The higher levels of blood mercury and urinary arsenic could be explained by the greater seafood consumption among the Korean population. This biomonitoring study of blood or urine heavy metals in the Korean general population provides important reference data stratified by demographic and lifestyle factors that will be useful for the ongoing surveillance of environmental exposure of Koreans to toxic metals.

Single strand DNA breaks in T- and B-lymphocytes and granulocytes in workers exposed to benzene

Comet assays were carried out to evaluate DNA damage in T- and B-lymphocytes and granulocytes from 41 workers exposed to benzene in a printing company and 41 unexposed donors. In T-lymphocytes, DNA damage was slightly higher in exposed workers than in controls. The tail moments in the two groups were 1.75+/-0.29 and 1.47+/-0.41, respectively (P<0.0006). DNA damage of B-lymphocytes in the two groups showed the most significant difference among the three cell types. The tail moments were 3.86+/-0.71 and 1.51+/-0.39, respectively (P<0.0001). In granulocytes, DNA damage was also different, the tail moments being 3.61+/-0.75 and 2.60+/-0.59, respectively (P<0.0001). The comparison of DNA damage in both groups shows that B-lymphocytes could be a useful target in biomonitoring of human exposure to low levels of benzene.

DNA damage in T- and B-lymphocytes and granulocytes in emission inspection and incineration workers exposed to polycyclic aromatic hydrocarbons

In this study, we investigated by using comet assay the effects of polycyclic aromatic hydrocarbon (PAH) as a major factor on DNA damage of workers exposed to exhaust fumes. Twenty-four workers from three automobile emission inspection companies, 28 workers from a waste incinerating company, and 43 matched, unexposed healthy subjects were enrolled in the study. The mean values of 1-hydroxypyrene (1-OHP) in automobile emission inspection and waste incineration workers were 0.27+/-0.19 and 0.57+/-0.46 micromol/mol creatinine, respectively, and the mean values of 2-naphthol in automobile emission inspectors and waste incineration workers were 4.80+/-4.01 and 8.30+/-4.79 mol/mol creatinine, respectively. Significant difference in urinary metabolites, 1-hydroxypyrene and 2-naphthol was found between smokers and non-smokers in exposed groups and it may be due to the amounts of smoking cigarettes. In T-lymphocytes, DNA damage in control subjects, emission inspection workers and incineration workers were 1.42+/-0.22, 1.41+/-0.22 and 1.76+/-0.27, respectively. DNA damage of B-lymphocytes in the three groups showed the most significant differences of three cell types. The tail moments of the B-lymphocytes of control subjects, emission inspection and incineration workers were 1.40+/-0.27, 2.44+/-0.32 and 2.36+/-0.37, respectively. In granulocytes, DNA damage was also different, the tail moments being 2.72+/-0.59, 3.32+/-0.38 and 2.85+/-0.49, respectively. Although 1-OHP and 2-naphthol levels were statistically increased in smokers in workers exposed to PAHs, exposed smoking and non-smoking workers did not show any significantly difference in terms of Olive tail moments. Our results suggest that PAH causes single strand DNA breakage in human T- and B-lymphocytes, and granulocytes. A comparison of DNA damage in three groups showed that B-lymphocytes are useful target in the biomonitoring of human exposure.

Korea National Survey for Environmental Pollutants in the human body 2008: 1-hydroxypyrene, 2-naphthol, and cotinine in urine of the Korean population

The Korea National Survey for Environmental Pollutants in the human body conducts representative Korean population studies, which were first initiated in 2005 in Korea. This study was conducted from 2008 to 2009 to determine the exposure levels of polycyclic aromatic hydrocarbons and nicotine in the Korean general population. The study population consisted of 4702 adult subjects from 196 sampling locations including coastal, rural, and urban areas. The urinary levels of 1-hydroxypyrene, 2-naphthol, and cotinine were measured for exposure of polycyclic aromatic hydrocarbons and nicotine. The geometric means of the urinary 1-hydroxypyrene, 2-naphthol and cotinine concentrations in the Korean general population were 0.15 μg/L (95% confidence interval (CI): 0.13-0.17), 3.84 μg/L (95% CI: 3.57-4.11) and 47.42 μg/L (95% CI: 40.52-54.32) respectively. When these values were compared with reference ranges for the United States and Germany, the levels of 1-hydroxypyrene, 2-naphthol, and cotinine were very similar for Korea and Germany, however, these levels were slightly lower in the United States. This study is the first nationwide survey of exposure to polycyclic aromatic hydrocarbons and nicotine in Korea and provides a background reference range for exposure to polycyclic aromatic hydrocarbons and nicotine in the Korean general population.

Evaluation of biological monitoring markers using genomic and proteomic analysis for automobile emission inspectors and waste incinerating workers exposed to polycyclic aromatic hydrocarbons or 2,3,7,8,-tetracholrodedibenzo-p-dioxins.

In this study, we investigated the effects of PAHs and dioxin on mRNA and plasma protein expression using genomic and proteomic analysis for automobile emission inspectors and waste incineration workers. About 54 workers from automobile emission inspection offices, 31 workers from waste incinerating company and 84 unexposed healthy subjects were enrolled in this study. Urine and air samples were collected and analyzed by HPLC and GC/MS. Comet assays were carried out to evaluate any DNA damage in mononuclear and polynuclear cells. A significant difference in Olive tail moments in mononuclear cells was observed between exposed and control subjects (P <0.0001). To examine the differences of the gene expression profile in automobile emission inspectors and waste incineration workers, radioactive complementary DNA microarrays were used to evaluate changes in the expression of 1,152 total genes. The gene expression profiles showed that 11 genes were up-regulated and 4 genes were down-regulated in waste incinerating workers as compared with controls. Plasma proteins were analyzed by 2-dimentional electrophoresis with pH 3-10 NL IPG Dry strip. The protein expression profiles showed that 8 proteins were up- regulated and 1 protein, haptoglobin, was down- regulated in automobile emission inspectors and waste incineration workers. Serum paraoxonase/ arylesterase was found only in the plasma of waste incineration workers. The expression of genes and proteins involved in oxidative stress were up-regulated in both automobile emission inspectors and waste incineration workers. Several proteins, such as transthyrethin, sarcolectin and haptoglobin, that were highly up- or down-regulated, could serve as biological monitoring markers for future study.

Effects of Hair Dyeing on DNA Damage in Human Lymphocytes

Effects of Hair Dyeing on DNA Damage in Human Lymphocytes: Jin‐A Choa, et al. Department of Beauty Arts, Seokyeong University, Korea—Comet assays were carried out to evaluate DNA damage in human lymphocytes from 20 volunteers before and after hair dyeing. DNA damage in lymphocytes was found to be slightly higher in volunteers after hair dyeing. Tail moments before and after hair dyeing were 1.47 ± 0.41 and 1.75 ± 0.29 respectively (p<0.0008). DNA damage in lymphocytes showed significant difference with treatment and heating time. The tail moments after 15 min of treatment time before and after hair dyeing were 1.44 ± 0.22 and 1.85 ± 0.36, respectively (p=0.0004) and the corresponding tail moments in 20 min of heating time before and after were 1.37 ± 0.15 and 1.78 ± 0.34 (p=0.0002). In conclusion, we found that an acute exposure of hair dyes with heating caused DNA damages in peripheral lymphocytes and that this damage had significant association with treatment and heating time.

Inter-and intra-individual variations of urinary endogenous metabolites in healthy male college students using 1H NMR spectroscopy

Abstract Background: Most human metabolomics studies have shown that spectral outputs of 1H nuclear magnetic resonance fingerprinting are strongly influenced by inter- and intra-individual variations; however, few studies have been performed to evaluate the inter- and intra-individual variations in urinary endogenous metabolites. Methods: We recruited 30 male college students to evaluate the factors affecting intra- and inter-individual variations in urinary endogenous metabolites. Statistical analysis for variations in urinary metabolites was performed after eliminating outliers found in principal component analysis (PCA) plots. Results: Inter-individual variations were relatively low for 2-oxoglutarate, succinate, citrate, dimethylglycine, and taurine, but high for trimethylaminoxide (TMAO), hippurate, and lactate. Intra-individual variations for 2-oxoglutarate, citrate, dimethylglycine, and taurine were relatively low, but high for TMAO and hippurate. The factors affecting inter-individual variation of lactate were age, body mass index, beverages, and alcohol, whereas the factors affecting intra-individual variation of lactate were age and fish. Kim Chi intake affected the inter-individual variation of succinate, citrate, TMAO, and hippurate; however, it did not affect the intra-individual variation of endogenous metabolites. Conclusions: Our results showed that inter- and intra-individual variations in urinary endogenous metabolites were very large, and significant factors affecting inter- and intra-individual variation were diverse, even after eliminating outliers in PCA analysis. Clin Chem Lab Med 2009;47:188–94.

Ethanol-induced DNA damage and repair-related molecules in human intestinal epithelial Caco-2 cells

The acute administration of ethanol to intestinal epithelial cells causes increased intestinal permeability and the translocation of endotoxins. The changes caused by ethanol in intestinal cells may be related to oxidative stress and DNA damage. However, DNA damage and repair-related molecules which act against stresses, including ethanol, have not been fully investigated in intestinal cells. Heat shock proteins (Hsps) are involved in the recovery and protection from cell damage and may be associated with DNA repair. Therefore, the aim of our study was to investigate cytotoxicity, DNA damage and the expression of DNA repair-related molecules, antioxidant proteins and Hsps in intestinal cells exposed to ethanol. Human intestinal Caco-2 cells were incubated with 1–8% ethanol for 1 h. Cell viability and DNA damage were determined using the MTT and comet assays, respectively. We measured DNA repair-related molecules, including DNA polymerase β, apurinic/apyrimidinic endonuclease/redox factor-1 (APE/Ref-1), growth arrest and DNA damage 45α (GADD45α) and proliferating cell nuclear antigen (PCNA), in Caco-2 cells using western blot analysis. We also measured glutathione peroxidase-1 (GPx-1), peroxiredoxin-1 (PRX-1), superoxide dismutase-2 (SOD-2), Hsp10, Hsp27, Hsp60, heat shock cognate (Hsc)70, Hsp70 and Hsp90. The viability of the Caco-2 cells exposed to ethanol decreased at concentrations ≥7% (P<0.05). The Olive tail moment, indicating DNA damage, increased dose dependently in ≥3% ethanol (P<0.05). Among the DNA repair proteins, the expression of PCNA and APE/Ref-1 increased significantly at 1% ethanol. Antioxidant enzymes, including GPx-1, PRX-1 and SOD-2, had an increased expression at 1% ethanol. Hsp10, Hsp27 and Hsp70 expression also increased significantly at 1% ethanol. In conclusion, the expression of DNA repair molecules, antioxidants and Hsps increased in intestinal Caco-2 cells exposed to low concentrations of ethanol. In particular, PCNA, APE/Ref-1, Hsp10, Hsp27 and Hsp70 were sensitive to low ethanol concentrations, indicating that they may be useful in evaluating the DNA repair and cytoprotective effects of the drug against stress in intestinal cells.

DNA Damage in T and B Lymphocytes, Bone Marrow, Spleens, and Livers of Rats Exposed to Benzene

Abstract Single-cell gel electrophoresis assays were performed in order to evaluate DNA damage occurring in the T and B lymphocytes, spleens, bone marrow, and livers of rats exposed to benzene at a concentration of 100, 200, or 400 ppm for 2 or 4 wk. The level of t,t-muconic acid (t,t-MA), which is a urinary benzene metabolite, was determined. In the control rats, mean Olive tail moments in the T and B lymphocytes were 1.507 ± 0.398 and 1.579 ± 0.206, respectively. DNA damage in the T and B lymphocytes exposed to 400 ppm benzene for 4 wk caused those rats to exhibit the highest Olive tail moments, with their values measured as 4.351 ± 0.510 and 3.140 ± 0.631, respectively. Also, the t,t-MA levels increased directly with increasing benzene exposure time and dose during the 4 wk. After 4 wk, the levels of t,t-MA in urine from rats exposed to 100, 200, and 400 ppm were 19.30 ± 5.62, 30.36 ± 4.46, and 46.93 ± 9.10 mg/g creatinine. In conclusion, the present study demonstrates that benzene exposure results in significant DNA damage in the T and B lymphocytes, bone marrow, spleens, and livers of rats. DNA damage in the blood cells and organs was also discovered to vary directly with benzene exposure, in both a dose-dependent and time-dependent manner. In addition, a similar trend regarding DNA damage was found in the blood cells and organs, and evidenced a good association with the level of t,t-MA in the urine.

Comparison of immunnological and genotoxicological parameters in automobile emission inspectors exposed to polycyclic aromatic hydrocarbons

In this study, we investigated the immunotoxicities of polycyclic aromatic hydrocarbons in 54 automobile emission inspectors and in 84 control subjects, and evaluated associations between immunological and genotoxicological parameters. Specific surface antigens of peripheral lymphocytes, namely, CD3, CD4, CD8, CD19, and CD69 were subjected to measure immune status in automobile emission inspectors and control subjects. T-and B-cells showed no significant differences between automobile emission inspectors and control subjects (p=0.740 and 0.395). In addition, the ratio of T helper cells to T cytotoxic cells was not deferent (p=0.144). However, T-cell activation was found to be significantly higher in automobile emission inspectors (p=0.041), but not B-cell activation. The levels of two cytokines (IL-4 an INF-γ) and four immunoglobulins (IgA, IgE, IgG, and IgM) were also determined in automobile emission inspectors and control subjects. All immunoglobulin types were lower in automobile emission inspectors, but this was significant only for IgG (0.047). In addition, the levels of two cytokines, IL-4 and INF-γ, were also higher in automobile emission inspectors, though this was not significant. DNA damage in mononuclear and polynuclear lymphocytes and in the level of urinary metabolites, 1-OHP and 2-naphthol, were evaluated in automobile emission inspectors and in control subjects and significant differences were found between the two groups. Examinations of urinary metabolites, DNA damage, and immunological parameters, including leukocyte subpopulations, immunoglobulins, and cytokines, showed that the cytokines levels were associated with the levels of two urinary metabolites, 1-OHP and 2-naphthol.