• Journal of Preventive Medicine and Public Health
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• v.54 no.1
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• pp.37-45
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• 2021

Objectives: Bisphenol A (BPA) is used in the electrical, mechanical, medical, and food industries. Previous studies have suggested that BPA is an endocrine disruptor. Regulation of BPA has led to increased use of bisphenol F (BPF) and bisphenol S (BPS). However, few studies have investigated the associations of BPF and BPS with thyroid dysfunction in children. Our study investigated the associations of prenatal BPA and early childhood BPA, BPF, and BPS exposure with thyroid function in 6-year-old children. Methods: Prenatal BPA concentrations were measured during the second trimester of pregnancy in an established prospective birth cohort. We measured urinary BPA, BPF, and BPS concentrations and thyroid hormone levels (thyroid-stimulating hormone, total T3, and free T4) in 6-year-old children (n=574). We examined the associations between urinary bisphenol concentrations and percentage change of thyroid hormone concentrations using multivariate linear regression. We also compared thyroid hormone levels by dividing the cohort according to BPA, BPF, and BPS concentrations. Results: The associations between prenatal BPA and total T3 levels were statistically significant in all models, except for girls when using a crude model. The associations between urinary BPA and BPS concentrations and levels of all thyroid hormones were not statistically significant. However, we observed that lower free T4 levels (-1.94%; 95% confidence interval, -3.82 to -0.03) were associated with higher urinary BPF concentrations in girls only. Conclusions: Our findings identified significant associations between prenatal BPA exposure and total T3 levels in all children and between BPF exposure and free T4 levels in girls only.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.3
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• pp.284-290
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• 2023

Objectives: Work environment assessments were conducted to investigate epidemiologically several cases of lung cancer and COPD (chronic obstructive pulmonary disease) among workers in domestic quarries. Methods: We visited three quarries in South Korea where an epidemiological investigation was requested and measured total dust, respirable dust, and crystalline silica on rock drilling workers (4 people) and rock chipping workers (13 people). Measurement and analysis were conducted according to NIOSH (National Institute for Occupational Safety & Health) method 0500, NIOSH method 0600 for respirable dust, and NIOSH method 7500 for crystalline silica. Results: Among rock drilling workers the AMs (arithmetic mean) of total dust concentrations, respirable dust concentrations, and crystalline silica concentrations were 3.462 mg/m³ (range: 0.764~6.085 mg/m³), 0.613 mg/m³ (range: 0.153~1.251 mg/m³), and 0.105 mg/m³ (range: 0.012~0.228 mg/m³), respectively. Among rock chipping workers, the AMs of total dust concentrations, respirable dust concentrations, and crystalline silica concentrations were 2.446 mg/m³ (range: 0.156~8.494 mg/m³), 0.488 mg/m³ (range: 0.028~1.536 mg/m³), and 0.099 mg/m³ (range: 0.004~0.274 mg/m³), respectively. Conclusions: Although it cannot be said that the dust concentrations were high for both rock drilling workers and rock chipping workers, the concentrations of crystalline silica were found to be high. If such work is performed for a long period of time, diseases such as lung cancer and COPD may occur, so the work environment needs to be improved.

• Journal of Aquaculture
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• v.15 no.1
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• pp.49-60
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• 2002

Research on practices for improving water quality in channel catfish Ictalurus punctatus ponds was conducted at the Auburn University Fisheries Research Station, Auburn, Alabama, in 1998 and 1999. The objective of this two-year study was to determine better management practices to enhance water quality and improve production efficiency. In the first year, oxidation of bottom soil by drying, tilling, and applying sodium nitrate was performed (dry-till and dry-till with sodium nitrate treatments). The second year, based on the results obtained during the first year, precipitation of phosphorus (P) from water by applying gypsum was compared to the dry-till treatment (dry-till and dry-till with gypsum treatments). Control ponds were not subjected to bottom drying, tilling, sodium nitrate, or gypsum treatment. Channel catfish fingerings were stocked at 15,000/ha. In the first year, water in ponds from dry-till and dry-till with sodium nitrate treatments had lower concentrations (P < 0.01) of soluble reactive P, nitrate ($NO_{3} ^{-}) and nitrite ($NO_{2} ^{-}) nitrogen (N), total ammonia ($NH_3$) nitrogen, total suspended solids and turbidity, and higher values of pH, Secchi disk visibility, total alkalinity, total hardness, and calcium ($Ca^{2+}) hardness than water in control ponds. Ponds of the dry-till treatment also had lower concentrations (P < 0.01) of total P and total N than control ponds. Total fish production and survival rate did not differ among the treatments (P > 0.05). The findings suggested that drying and tiling pond bosoms between crops could achieve water quality improvement. Applying sodium nitrate to dry, tilled pond bosoms did not provide water quality improvement. In the second year, the treatment with the best results from the first year, dry-till, was compared with a dry-till with gypsum treatment. Enough gypsum was applied to give a total hardness of about 200 mg/L, and gypsum was reapplied as needed to maintain the hardness. Compared to the control, dry-till and dry-till with gypsum treatments had lower concentrations (P < 0.01) of total and soluble reactive P, total N, and total $NH_3$-N, and higher concentrations (P < 0.01) of dissolved oxygen. Ponds of the duty-till with gypsum treatment also had lower concentrations (P < 0.01) of chlorophyll $\alpha$, chemical oxygen demand, and total alkalinity than the control. Total fish production and survival rate did not differ (P > 0.05) among the treatments. These findings suggest that drying and tilling pond bosoms between crops and treating low hardness waters with gypsum could achieve water Quality improvement.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.1
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• pp.10-17
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• 2020

Objectives: This study was performed to evaluate the total dust, size-selective dust, and heavy metal concentrations generated inside and outside toll booths on an expressway and to identify the source through analysis of the components of the deposited dust. Methods: A total of 32 samples were collected from eight expressway toll booths. Each total dust sample was collected using a 37 mm PVC filter attached to a personal air sampler. Heavy metal samples were collected according to NIOSH method 7300. The size-selective dust concentrations were identified using a DustMate, and deposited dust was analyzed by WD-XRF and UHR-FE-SEM. Results: The geometric mean concentrations of the total dust inside and outside the toll booths were 337.5 ㎍/㎥ and 342.7 ㎍/㎥, respectively. The overall concentrations of TSP, PM₁₀, PM_2.5, and PM1 were higher on the outside of the toll booths, as the particle size of dust was larger, and higher in the underground passage as the dust size was smaller. The real-time analysis of the dust concentrations of TSP, PM₁₀, PM_2.5, and PM1 revealed to be higher at morning and evening times than other times because of heavy traffic. The element components of deposited dust in the toll booth were related to natural sources rather than artificial sources. Among the chemical components in the deposited dust analyzed by WD-XRF, SiO₂ was the highest. For the elements analyzed by UHR-FE-SEM, C was the highest, followed by O, and Si. Conclusions: In order to reduce the dust concentrations around toll booths on an expressway, it is necessary to periodically clean surrounding areas such as underground passages, and it is also necessary to remove deposited dust inside the toll booth from time to time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.384-391
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• 1996

This study was designed to investigate effects of lobster shrimp chitosan on serum and liver lipid levels in rats fed high fat and cholesterol diets. Male Sprague-Dawley rats of 4-weeks old, weighing 70$\pm$5g, were fed experimental diets for 3 weeks: basal diet+5% cellulose(group 1), high lipid diet+5% cellulose(group 2, control group), high lipid diet+5% balloon flower root(group 3), high lipid diet+5% cellulose(group 4, high lipid diet+5% lobster shrimp chitosan(group 5). Concentrations of total cholesterol, HDL-cholesterol, LDL-cholesterol, free cholesterol, cholesteryl ester, triglyceride, phospholipid in serum and liver were determined. The results obtained were as followes: Serum total cholesterol concentration were significantly reduced in all supplemented group compared with control. HDL-cholesterol concentrations were higher in groups 1, 4, and 5 and the ratios of HDL-cholesterol to total cholesterol concentration were higher in groups 1, 4, while the atherogenic-indices were lower in groups 1, and 4 than control. Concentrations of LDL, LDL-cholesterol and free cholesterol, cholesteryl ester were significantly lower in all supplemented groups than the control group. Concentrations of phospholipid and triglyceride were lower in groups 3, 4, 5, while activities of GPT and GOT were significantly lower in groups 4, 5 than the other group. Concentrations of calcium, magnesium and phosphorous were high in all treatment groups compared to the control group. Liver contents of total cholesterol, free cholesterol and cholesteryl ester were lower in the groups 1, 3, 4, and 5 than in the control group, especially lower in groups 1, and 5. Liver triglyceride and phospholipid concentrations were significantly lower in the groups 1, and 5 than in the other groups. The results from the data suggested that the experimental diet containing 5% lobster shrimp chitosan was effective to reduce the serum and liver lipids.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.1
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• pp.63-66
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• 1985

Phytoplankton (microplankton and nannoplankton) biomass as chlorophyll-a concentrations ana ratios of nannoplanktons ($size<60{\mu}m$) to total phytoplanktons ($size<300{\mu}m$) were measured in the coastal waters of Korea in fall, 1983. Chlorophyll-a concentrations of total phytoplankton ranged from 0.202 to 1.350 $mg/m^3$ with a mean and standard deviation, $0.597{\pm}0.287\;mg/m^3$, Chlorophyll-a concentrations of the nannoplankton ranged from 0.100 to $0.855\;mg/m^3$ with a mean and standard deviation, $0.372{\pm}0.201\;mg/m^3$, and it accounted for 25.4 to $83.3\%$ with an average $62.2\%$ to total phytoplankton biomass as chlorophyll-a concentrations. The amounts of chlorophyll-a concentrations of total phytoplankton in the water column below the surface area of $1m^2$ varied from 16.12 to $17.67\;mg/m^2$ with a mean $17.01\;mg/m^2$.

• Journal of Nutrition and Health
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• v.32 no.2
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• pp.137-149
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• 1999

This study was performed to investigate the effets of hesperidin extracted from tangerine peel on Cadmium (Cd) and lipid metabolism lipid peroxide formation, and antioxidative enzyme activities in rats. Forty-eight male Sprague-Dawley rats weighing 158.3$\pm$3.5g were blocked into eight groups according to body weight. Rats were raised for three weeks with diets containing 0 or 0.04%(w/w) cadmium chloride and 1%(w/w) extracted hesperidin from tangerine peel, commercial hesperidin or naringin. Food intake, weight gain and food efficiency ratio were significantly lower in the Cd-administered groups. The Cd concentrations in blood and liver and the Cd excretions in urine and feces were significantly higher in the Cd-administered groups. Among the Cd groups, blood Cd concentrations were decreased, fecal Cd excretions were increased, and Cd retenition ratios were decreased by feeding flavonoid diets. Plasma total lipid concentrations were significantly lower in the extracted hesperidin group, plasma triglyceride concentrations were significantly lower in the extracted hesperidin and naringin groups. Plasma HDL-cholesterol concentrations and HDL : total cholesterol ratios were increased by feeding flavonoids. Among the Cd groups, liver total lipid concentratons were decreased by feeding flavonoids. Fecal total lipid, fecal cholesterol, and fecal triglyceride excretions were significantly higher in the naringin group, and they were increased by feeding flavonoids among Cd groups. Thiobarbituric acid reactive substance concentrations in plasma and liver were higher in Cd groups, and were significantly decreased by feeding flavonoids. The activities of erythrocyte catalase, superoxide dismutase and glutathione peroxidase showed a tendency to increase by feeding. The activities of liver catalase, superoxide dismutase and glutathione peroxidase were not significantly affected by administering Cd or flavonoids. In conclusion, all flavonoids that were used in this experiment inhibited lipid peroxide formation in plasma and liver, but this effect was not caused by the increased in the activities of antioxidative enzymes.

• Journal of Society of Preventive Korean Medicine
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• v.4 no.2
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• pp.294-312
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• 2000

The effects of Gamisoohwabunchungum and Gamisoohwabunchungum plus Cervi Pantotrichum Cornu on rats with nephrosis induced by a single tail-intravenous injection of PAN(puromycin amjnonucleoside), 2.5mg/100g of body weight was evaluated in the present study. The effects of Gamisoohwabunchungum and Gamisoohwabunchungum plus Cervi Pantotrichum Cornu on PAN nephrosis was evaluated by measuring the concentrations of albumin, total protein, total lipid, cholesterol, triglyceride in the serum and the amount of protein in the urin. The results are summarized as follows; 1 In The Gamisoohwabunchungum and Gamisoohwabunchungum plus Cervi Pantotrichum Cornu group as compared to The Control group, The concentrations of albumin and total protein in the serum were significantly increased. 2. In The Gamisoohwabunchungum and Gamisoohwabunchungum plus Cervi Pantotrichum Cornu group as compared to The Control group, The concentrations of total lipid, cholesterol and triglyceride in the serum were significantly decreased 3. In The Gamisoohwabunchungum and Gamisoohwabunchungum plus Cervi Pantotrichum Cornu group as compared to The Control group, The amount of urine protein during 24 hours were significantly decreased . 4. In The Gamisoohwabunchungum plus Cervi Pantotrichum Cornu group as compared to The Gamisoohwabunchungum group, The concentrations of total protein in the serum were significantly increased. 5. In The Gamisoohwabunchungum plus Cervi Pantotrichum Cornu group as compared to The Gamisoohwabunchungum group, The concentrations of cholesterol and triglyceride in the serum were significantly decreased To conclude, it can be inferred that Gamisoohwabunchungum and Gamisoohwabunchungum plus Cervi Pantotrichum Cornu have the effects of improving proteinuria, hypoproteinemia, hyperlipidemia in nephrotic syndrome.

• Journal of Nutrition and Health
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• v.30 no.8
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• pp.936-951
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• 1997

As fat consumption has increased in Korea , serum cholesterol concentrations have risen and the prevalence of atherosclerosis increased. The aim of the present study was to investigate the association among apolipoprotein E (Apo E) phenotypes, dietary fat consumption, plasma lipoprotein levels and fatty acid compositions of red blood cells in young healthy women. Seventy-one percent of participants had Apo E3/3, 14.9 percent had ApoE3/2 , 11.8% had Apo E4/3 and 1.2% had Apo E4.2. The subjects daily consumed approximately 1760kcal containing 29 energy % of fat. The ratio of polyunsaturated fat to saturated fat in a diet was 0. 73 . There were no significant differences of nutrient intakes according to Apo E phenotypes. Total cholesterol concentrations of subjects averaged approximately 160mg/dl , but 12 percent of them had over 200mg/dl, which is higher than the range recommended by the National Cholesterol Deucation Program. Notably, most subjects with 210mg/dl had Apo E4 isoforms. Subjects with Apo E4 isoforms had significantly higher total and LDL-cholesterol concentrations than those with Apo E3/2. Also subjects carrying Apo E4 isoforms tended to accumulated more fat in the body. Their BMI , WHR and arm fat area appeared to be how can arm fat area be greater no you mean grater, please check work vsage than subjects with Apo E3 isoforms, but not significantly. Fat intakes slightly influenced serum cholesterol levels. Myristic aicd intakes were positively correlated to serum total and LDL-choelsterol levels. Polyunsaturated fatty acid intakes were negatively correlated to serum total choelsterollevels. The results of 소냐 study suggest that , people with Apo E4 isoforms need to prevent the raising of serum total and LDL -cholesterol concentrations by reducing calorie and fat intakes and by maintaining a normal weight.

• Journal of Nutrition and Health
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• v.33 no.5
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• pp.497-501
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• 2000

We investigated the effect of tea fungus/kombucha(TF) beverage on serum and liver lipid metabolism in growing male rats. The rats(Sprague-Dawley) were divided into five groups; control(TF free water), 20 or 40% TF groups(20 or 40% TF in water) and 20 or 40% TFS groups(20 or 40% TF autoclaved in water) according to the level of TF supplementation. The rats were fed ad libitum each of the experimental beverage for 7 weeks. The body weight gain of all the TF and TFS groups were similar to that of the control group. The total lipid and triglyceride concentrations of serum in the 40% TF group were increased more than those in the control group, but those in the 20% TF and 20% TFS groups were similar to that of the control group. The total cholesterol, HDL-cholesterol concentrations, HDL-cholesterol / total cholesterol ratio and atherogenic index of serum in all the TF and TFS groups were similar to those of the control group. The LDL-cholesterol concentration of serum was significantly lower in the 20% TF group than that in the control group. The LDL-cholesterol concentration of serum was significantly lower in the 20% TF group than that in the control group, but those of the 40% TF, 20% TFS and 40% TFS groups were similar to that of the control group. The liver weights of all the TF and TFS groups were heavier than that of the control group. The concentrations of hepatic triglyceride in the 20% TF and 20% TFS groups were significantly decreased, compared with that in the control group. The concentrations of hepatic total cholesterol in all the TF and TFS groups were significantly more decreased than that in the control group. These results indicated that the liver weights of tea fungus/kombucha beverage feeding rats were increased, also the serum triglyceride and total cholesterol concentrations of 40% TF feeding rats were increased. but the serum LDL-cholesterol, hepatic triglyceride and cholesterol levels of 20% TF feeding rats were decreased.