• Journal of Environmental Health Sciences
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• v.48 no.1
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• pp.52-58
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• 2022

Background: Few studies have evaluated the exposure to phthalates via inhalation of floor dust in children's living areas. Objectives: This study evaluated the concentration and exposure level of phthalates emitted from indoor floor dust in children's living areas. Methods: This study utilized the results of a survey conducted by the Ministry of Environment in 2019. Indoor dust was collected from 150 households with children aged 3~7 and 67 daycare centers or local children's centers by using vacuum cleaners. It was analyzed by gas chromatography mass spectrometry. Six types of phthalates were analyzed: Bis (2-ethylhexyl) phthalate (DEHP), Dibutyl phthalate (DBP), Benzyl butyl phthalate (BBP), Di-N-octyl phthalate (DNOP), Diisononyl phthalate (DINP), Di -isodecyl phthalate (DIDP). Results: The medians of DEHP concentrations were 1,028 and 1,937 mg/kg in homes and daycare centers, respectively. The median and maximum values of daily intake were calculated by applying the median and 95th percentile values (the upper 5% of the total concentration) in dust measured in the homes. The DEHP median value was 1.6 ㎍/kg/bw/day, and a maximum A value of 7.8 ㎍/kg/bw/day was calculated. When the childcare center values were applied, the median daily intake of DEHP was 3.1 ㎍/kg/bw/day and the maximum value was 29.2 ㎍/kg/bw/day. As a result of calculating the daily intake by integrating the values of home and childcare facilities, the median and maximum values of daily intake were 1.9 and 10.9 ㎍/kg/bw/day, respectively. Conclusions: This study derives phthalate concentrations among the floor dust in homes and childcare facilities where children mainly spend time, and suggests their intake of phthalates through this. In particular, it was newly suggested that the phthalate concentrations in homes and childcare facilities are different, resulting in differences in intake.

• Journal of Environmental Health Sciences
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• v.49 no.3
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• pp.159-168
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• 2023

Background: An ongoing environmental exposure assessment of humidifier disinfectants (HDs) has been conducted since November 2011 among individuals who experienced HD exposure-related adverse health effects. It is being performed in order to determine and quantify exposure to humidifier disinfectants in victims and their families. To date, the assessment has encompassed Cycles I-to-V. There is no report summarizing the characteristics of the subjects from the overall cycles. Objectives: We intended to examine the individual characteristics related to demographics, HD usage, and HD exposure using integrated data from Cycles I-to-V of the environmental exposure assessment of HDs and the changes with the cycles. Methods: We included 7,543 individuals who participated in Cycles I-to-V of the environmental exposure assessment of HDs. We summarized the participants' characteristics regarding their demographics (e.g., sex, education level, and age), HD usage history (e.g., product name, ingredient, and frequency of HD use), and HD exposure (e.g., daily time of HD use, cumulative time of HD use, and exposure intensity). In addition, their characteristics were compared across the cycles of the exposure assessment. Results: Among the 7,543 participants from Cycles I-to-V, there were more male participants than females (51.05% overall), except for Cycles I and III. Across all cycles, a higher proportion of survivors was observed than deceased individuals. While PHMG was the most prevalent ingredient in HDs throughout all the cycles, its proportion gradually decreased over the course of the examination cycles. Participants in Cycle I reported longer daily times of HD use compared to those in the subsequent cycles. On the other hand, cumulative time of HD use was shorter in the earlier cycles than in the later cycles. Conclusions: Using the integrated data from the full cycles of the environmental exposure assessment, this study identified changes in demographic characteristics as well as the HD exposure characteristics between the participants across different cycles.

• Fisheries and Aquatic Sciences
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• v.19 no.10
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• pp.44.1-44.8
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• 2016

Rockfish, Sebastes schlegelii (mean length $14.53{\pm}1.14cm$ and mean weight $38.36{\pm}3.45g$), were exposed for 4 weeks with the different levels of ammonia in the concentrations of 0, 0.1, 0.5, and 1.0 mg/L at 19 and $24^{\circ}C$. The indicators of growth performance such as daily length gain, daily weight gain, condition factor, and hematosomatic index were significantly reduced by the ammonia exposure and high temperature. The ammonia exposure induced a significant decrease in hematological parameters, such as red blood cell (RBC) count, white blood cell (WBC) count, hemoglobin (Hb), and hematocrit (Ht), whose trend was more remarkable at $24^{\circ}C$. Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were also notably decreased by the ammonia exposure. Blood ammonia concentration was considerably increased by the ammonia concentration exposure. In the serum components, the glucose, glutamic oxalate transaminase (GOT), and glutamic pyruvate transaminase (GPT) were substantially increased by the ammonia exposure, whereas total protein was significantly decreased. But, the calcium and magnesium were not considerably changed.

• Journal of Environmental Impact Assessment
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• v.9 no.3
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• pp.203-214
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• 2000

Health risk assessment is applied to streamlining LCA(Life Cycle Assessment) using Monte carlo simulation for probabilistic/stochastic exposure and risk distribution analysis caused by data variability and uncertainty. A case study was carried out to find benefits of this application. BTC(Benzene, Trichloroethylene, Carbon tetrachloride mixture alias) personal exposure cases were assumed as production worker(in workplace), manager(in office) and business man(outdoor). These cases were different from occupational retention time and exposure concentration for BTC consumption pattern. The result of cancer risk in these 3 scenario cases were estimated as $1.72E-4{\pm}1.2E+0$(production worker; case A), $9.62E-5{\pm}1.44E-5$(manger; case B), $6.90E-5{\pm}1.16E+0$(business man; case C), respectively. Portions of over acceptable risk 1.00E-4(assumed standard) were 99.85%, 38.89% and 0.61%, respectively. Estimated BTC risk was log-normal pattern, but some of distributions did not have any formal patterns. Except first impact factor(BTC emission quantity), sensitivity analysis showed that main effective factor was retention time in their occupational exposure sites. This case study is a good example to cover that LCA with probabilistic risk analysis tool can supply various significant information such as statistical distribution including personal/environmental exposure level, daily time activity pattern and individual susceptibility. Further research is needed for investigating real data of these input variables and personal exposure concentration and application of this study methodology.

• Journal of Preventive Medicine and Public Health
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• v.57 no.2
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• pp.185-196
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• 2024

Objectives: Excess mortality associated with long-term exposure to fine particulate matter (PM_2.5) has been documented. However, research on the disease burden following short-term exposure is scarce. We investigated the cause-specific mortality burden of short-term exposure to PM_2.5 by considering the potential non-linear concentration-response relationship in Korea. Methods: Daily cause-specific mortality rates and PM_2.5 exposure levels from 2010 to 2019 were collected for 8 Korean cities and 9 provinces. A generalized additive mixed model was employed to estimate the non-linear relationship between PM_2.5 exposure and cause-specific mortality levels. We assumed no detrimental health effects of PM_2.5 concentrations below 15 ㎍/m³. Overall deaths attributable to short-term PM_2.5 exposure were estimated by summing the daily numbers of excess deaths associated with ambient PM_2.5 exposure. Results: Of the 2 749 704 recorded deaths, 2 453 686 (89.2%) were non-accidental, 591 267 (21.5%) were cardiovascular, and 141 066 (5.1%) were respiratory in nature. A non-linear relationship was observed between all-cause mortality and exposure to PM_2.5 at lag0, whereas linear associations were evident for cause-specific mortalities. Overall, 10 814 all-cause, 7855 non-accidental, 1642 cardiovascular, and 708 respiratory deaths were attributed to short-term exposure to PM_2.5. The estimated number of all-cause excess deaths due to short-term PM_2.5 exposure in 2019 was 1039 (95% confidence interval, 604 to 1472). Conclusions: Our findings indicate an association between short-term PM_2.5 exposure and various mortality rates (all-cause, non-accidental, cardiovascular, and respiratory) in Korea over the period from 2010 to 2019. Consequently, action plans should be developed to reduce deaths attributable to short-term exposure to PM_2.5.

• The Korean Journal of Pesticide Science
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• v.18 no.2
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• pp.95-103
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• 2014

In this study, we monitored the residues of organophosphate pesticides (OP) in eight fruit vegetables grown in Korea, and assessed risk levels of acute and chronic exposure of OP through the consumption of fruit vegetables. Chlorpyrifos, EPN, methidathion and phosphamidon in eight fruit vegetables were detected in this study. The results of cumulative assessment of national estimated short term intake for acute exposure of OP were due to the following order; eggplant, tomato, squash and cucumber. Total theoretical maximum daily intake calculated at first step of chronic exposure assessment for registered OP in Korea was 76.14%, compared with acceptable daily intake ADI) based on chlorpyrifos. In addition, total national estimated maximum daily intake calculated at second step of chronic exposure assessment was 13.949%, compared with ADI. Third chronic assessment was conducted by probabilistic approach using OP residues detected in eight fruit vegetables and showed that total exposure risk was very low, corresponding to 0.0001% compared to ADI. Based on those finding, the risk of organophosphate pesticides in fruit vegetables was considered quantitatively negligible. In future, further investigation to expand the target should be followed to do more accurate and detailed risk assessment.

• Research in Community and Public Health Nursing
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• v.17 no.3
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• pp.376-386
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• 2006

Purpose: This study was conducted to analyze the exposure of female high school students to Internet pornography and its related factors. Methods: A total of 392 female high school students were selected through convenience sampling. Data were collected using self-reported questionnaires from June 27 to July 8, 2005. Results: 1. As for exposure to Internet pornography, 61.0% of the respondents had been exposed to Internet pornography and 29.7% had their first exposure to Internet pornography when they were in the 3rd grade of middle school. In addition, 87.9% of the respondents spent less than 30 minutes each time to view Internet pornography. In 41.8% of the respondents, the reason for seeing Internet pornography was curiosity about sexuality. 2. Both the level of sexual knowledge (t=3.174, p=.002) and attitude (t=2.567, p=.011) were significantly different between the exposure group and the non-exposure group. 3. Grade, daily mean time to use computer, and sexual knowledge had statistically significant effects on exposure to Internet pornography. Conclusion: It is necessary to make repeated study to find other variables that affect students' exposure to Internet pornography and to develop education programs to enhance students' coping ability against Internet pornography. Also, parents' concern over youth is necessary to prevent them from being exposed to Internet pornography.

• Korean Journal of Environmental Biology
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• v.42 no.1
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• pp.1-14
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• 2024

This study evaluated the risk of single and combined exposure to microplastics in zebrafish (Danio rerio) through biomarkers, such as survival rate, excretion rate, and histological alterations of organ systems. The experimental groups were the control(Cont.), single microplastics exposure group(MPs, 1.83%/fish total weight(g)), the copper group(Cu, 21.6 ㎍ L^-1), and a group with combined exposure to MPs and copper (MPs^*Cu). The experiment was conducted with individual exposure (7 days) for MP excretion rate analysis and group exposure (14 days) for biomarker analysis. The daily excretion rate of MPs tended to decrease in a time-dependent manner. The copper concentration in the body was not significantly different between single and combined copper exposure. The degeneration of mucous cells in the skin, capillary dilation of the gill lamella, increased intestinal mucous, hepatocyte hypertrophy, and the degeneration of glomeruli and renal tubules were observed in all exposure groups. These histological alterations showed the highest tendency in the MPs^*Cu group. In this study, the changes in biomarkers were attributed to the single effect of copper or the combined effect of copper and MPs rather than being solely influenced by MPs.

• Fisheries and Aquatic Sciences
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• v.20 no.3
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• pp.4.1-4.6
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• 2017

Juvenile Anoplopoma fimbria (mean length $16.8{\pm}2.2cm$, and mean weight $72.8{\pm}5.4g$) were exposed for 2 months with different levels of ammonia (0, 0.25, 0.50, 0.75, 1.00, and 1.25 mg/L). Growth performances such as daily length gain, daily weight gain, condition factor, and hepatosomatic index were significantly decreased by ammonia exposure. Hematological parameters such as red blood cell (RBC) count, hematocrit, and hemoglobin were also significantly decreased. In plasma inorganic components, calcium and magnesium were significantly decreased by ammonia exposure. In plasma organic components, there was no alteration in cholesterol and total protein. In enzyme plasma components, glutamic oxalate transaminase (GOT) and glutamic pyruvate transaminase (GPT) were significantly increased. The results of this study indicated that ammonia exposure can induce significant growth reduction and blood biochemistry alterations of A. fimbria.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.5
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• pp.687-697
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• 1998

In spite of increasing public concern about the human exposure to electric and magnetic fields(EMFs), there is little information about the EMF levels in the vicinity of power facilities and of home appliances. To provide such information, a nationwide survey for EMFs near overhead transmission lines has been conducted. The median values of the electric fields and magnetic fields of 153 transmission lines were 0.47 kV/m and 11.6 mG, respectively. The maximum values were 3.16 kV/m and 125 mG. These were low values in comparison with any EMF guidelines or standards of advanced contries. Measurements of the magnetic fields of typical home appliances and daily human exposure records have been also conducted. These magnetic field values were comparable to those of the transmission lines.