South Korea Research Articles

Nocturnal Artificial Light Exposure in Expectant Mothers and Risk of Congenital Glaucoma

Abstract Background While the impact of light pollution on human health is gaining recognition, its role in transmitting the effects of maternal exposure to the fetus remains unclear. This study is to investigate the association between exposure to artificial light at night (ALAN) during pregnancy and risk of congenital glaucoma. Methods All birth cohorts spanning from 2008 to 2011 in urban areas of South Korea, comprising over 90% of the total population, were identified in the Korean National Health Insurance database. Average levels of ALAN at the residential addresses of mothers during pregnancy were estimated using time-varying satellite data for a composite view of persistent night-time illumination at ∼1 km2 scale.The odd ratios (ORs) and 95% confidence intervals (CIs) of the association between residential ALAN and risk of congenital glaucoma - was computed using logistic regression. These calculations were adjusted for socio-demographic factors and area-level risk factors (night-time traffic noise and particulate matter with an aerodynamic diameter ≤ 10 μm). Results A total of 745,458 mother-father-child trios (mean [SD] age of the mothers, 32.4 [3.8] years; 387,275 [52.0%] boy) were included in the study. In fully adjusted models, an IQR (21.8 nW/cm2/sr) increase in ALAN level was associated with an OR of 1.12 (95% CI: 1.05, 1.19) for incident congenital glaucoma. The exposure-response curve demonstrated an upward slope with a threshold at approximately 62 nW/cm2/sr. Conclusions In this nationwide population-based case-control study, higher levels of residential ALAN during pregnancy were associated with increased risk of congenital glaucoma. Future studies with more detailed information on exposure, individual adaptive behaviors and potential mediators are warranted. Key messages • This study indicates an association between elevated levels of ALAN exposure in pregnant women and a heightened risk of congenital glaucoma in their offspring. • These results are consistent with a growing body of evidence underscoring the detrimental effects of ALAN on health, reinforcing its potential role as a risk factor for congenital glaucoma.

Quantifying Invasiveness Risk of Non‐Native Freshwater Fishes in South Korea Under a Changing Climate

ABSTRACTBiological invasions pose a serious threat to native biodiversity, and climate change intensifies the risk of non‐native species invasion in human‐altered environments, particularly in freshwater ecosystems. In South Korean freshwaters, the number of non‐native fish species increased significantly since the early 1950s. We screened risk of invasion by 43 freshwater fish species in South Korea using the Aquatic Species Invasiveness Screening Kit (AS‐ISK). Of these species, 26 (~ 61%) posed a high to very high risk of invasiveness. Black bullhead Ameiurus melas, brown bullhead Ameiurus nebulosus, North African catfish Clarias gariepinus, green sunfish Lepomis cyanellus, black carp Mylopharyngodon piceus, round goby Neogobius melanostomus, and Chinese sleeper Perccottus glenii were very high risk under current and predicted climate conditions. Striped snakehead Channa striata, longear sunfish Lepomis megalotis, smallmouth bass Micropterus dolomieu, white perch Morone americana, Eurasian perch Perca fluviatilis, and rudd Scardinius erythrophthalmus were high risk only under predicted climate conditions. Present risks were generally consistent with previous qualitative assessment, with some discrepancies, likely due to unobserved or under‐reported invasive traits of some species or a better ability of the present semi‐quantitative approach to estimate potential risks. Our results will inform South Korean decision‐making to potentially enhance regional cooperation across East Asia against transboundary introductions of aquatic invasive species.

Composite Risk Assessment of HNS Discharged from Marine Industrial Facilities: A Case Study on Incheon Port, South Korea

This study conducted a composite risk assessment to evaluate the environmental impacts of phenol, a Hazardous and Noxious Substance (HNS) released or leaked from port facilities. The study area was designated as the vicinity of Incheon Port, South Korea, where the volume of petrochemical-related materials is substantial and various industrial facilities are located. For the composite risk assessment, various vulnerability maps were developed, incorporating the dispersion range of phenol calculated through numerical modeling. The vulnerability maps were generated by classifying socio-environment, legally protected areas, habitats, and species, followed by integrating these individual vulnerability maps to construct an integrated vulnerability map. The composite risk assessment was conducted by considering both the integrated vulnerability map and the dispersion range of phenol. The assessment results indicated that the highest risk by depth was observed in the lower layers due to the settling characteristics of phenol. Spatially, areas where islands and coastlines converge exhibited relatively higher risks. This was attributed to the high concentrations of phenol released from industrial facilities, such as crude oil refineries, petrochemical plants, and organic compound manufacturers, in regions characterized by intense human activity, sensitive habitats, and legally protected areas. Continuous monitoring of these high-risk areas is crucial for assessing the environmental impacts of HNS substances like phenol.

Spatiotemporal Distribution of Mercury in Tree Rings and Soils Within Forests Surrounding Coal-Fired Power Plants

The release of mercury (Hg) from coal-fired power plants (CPPs) into local ecosystems poses substantial environmental and health hazards. This study was conducted in Chungcheong-nam-do, South Korea, a region featuring over half of the country’s coal power facilities, to estimate the impacts of CPPs on Hg distribution in forest ecosystems. By analyzing Hg concentrations in pine tree rings and soil at 21 locations around CPPs and comparing them to control sites and industrial zones, we present a nuanced understanding of the effects of CPPs on Hg concentration. The analysis of Hg concentrations in tree rings showed a significant decrease in Hg levels as the distance from the power plants increased, suggesting that CPPs primarily influence Hg distribution in trees within a 25 km radius. In contrast, soil Hg concentrations did not exhibit a clear trend. This may reflect the limitations of this study in accounting for the physicochemical properties of the soil at each sampling site. Nevertheless, the Potential Ecological Risk Index for soil Hg contamination indicated a higher risk rating within a 1 km radius of the CPPs compared to other locations. Hg concentrations in tree rings have shown a steady decline since the 1970s, suggesting the positive effects of air pollution regulations. This also highlights the value of tree core samples as effective tools for monitoring historical Hg pollution. Furthermore, the higher historical concentrations of Hg in tree rings imply that trees may have acted as sinks for atmospheric Hg in the past.

Prevalence of Low FIB-4 in MASLD-Related Hepatocellular Carcinoma: A Multicentre Study.

Major society guidelines recommend the fibrosis-4 index (FIB-4) as the initial step to risk stratifying people with metabolic dysfunction-associated steatotic liver disease (MASLD). We aimed to evaluate the proportion of people with MASLD-related hepatocellular carcinoma (HCC) and a low FIB-4. This cohort study included 613 consecutive adults (33% female) diagnosed with MASLD-related HCC from January 2008 to August 2023 at seven international centres in Australia, India, Japan, South Korea, Singapore and the United States. The primary objective was to determine the proportion of participants with a low FIB-4, defined as FIB-4 < 1.3, or < 2 if age > 65 years, in people without cirrhosis. The mean (±SD) age and body mass index were 71 (±11) years and 27 (±7) kg/m2, respectively. Overall, 235 participants (38%) did not have known cirrhosis. The median FIB-4 was 3.90 (IQR 2.42-6.42). A total of 78 participants (13%) had a low FIB-4. Among participants without known cirrhosis (n = 235), 62 participants (26%) had a low FIB-4. Participants with a low FIB-4 had larger median total tumour diameter (p < 0.001) and lower median serum alpha-fetoprotein (p = 0.005), compared to participants without a low FIB-4. Cirrhosis was associated with lower odds of low FIB-4, but not other factors such as male sex, type 2 diabetes, or obesity. More than a quarter of those with MASLD-related HCC without cirrhosis have a low FIB-4. The proposed clinical care pathways may not identify these people for further evaluation.

Metavirome Insights into the Diversity and Potential Pathogenic Infection of Chlamys farreri in the Coastal Seas of the Republic of Korea

Chlamys farreri is primarily cultivated in Japan, China, and South Korea. Although mass mortality of scallops has been occurring recently, likely caused by high temperatures or infectious diseases, the underlying cause remains unclear. Little is known regarding the viral diseases affecting them. Therefore, we explored DNA virus diversity in the mid-gut gland of C. farreri and compared it with that of seawater. C. farreri was cultivated at depths below 5 m from the sea surface in the coastal waters of South Korea and sampled from May to August 2018. Different DNA viral communities were observed in both C. farreri and seawater. In C. farreri, prevalent groups included Mimiviridae (7%), Poxviridae (6%), and Phycodnaviridae (5%). Conversely, the dominant groups in seawater were Autographiviridae (20%), Kyanoviridae (12%), and Zobellviridae (10%). We identified C. farreri-specific viral communities and potentially infectious viruses, such as Ostreid herpesvirus 1 and Abalone herpesvirus Victoria/AUS/2009. Furthermore, C. farreri acts as a reservoir for various viruses, which impact microbial community dynamics and disease transmission in marine ecosystems. Understanding these viral communities is crucial to protecting and restoring coastal ecosystems by highlighting their role in the transmission of potential avian- and bivalve-specific viruses.

SLR: Discovering STEAM Integrated Science Disciplines for Learning Planning for Primary School Students in Indonesia Towards the Era of Society 5.0

This research aims to find elements related to STEAM from 100 Google Scholar indexed articles resulting from scientific research. Elements related to STEAM can be implemented in elementary school students in facing the era of society 5.0. The method used in this research is the SLR (Literature Review System) PCR model (Planning, Conducting, Reporting) with the aim of systematically reviewing the literature to find elements related to STEAM based on research results from the last 7 years (2017-2024). The research results showed that other elements were compared with STEAM, such as language, social sciences, economics, religion, culture and literacy with the terms STREAM, SELAMeT, STREAME, STELAM and STEAMS and were even used as a basis for curriculum development such as in South Korea with the term WS-STEAM . Based on these findings, there are elements that can be used as a reference in developing learning plans in elementary schools towards the era of society 5.0 which are in accordance with the national basic education curriculum, especially in elementary schools in Indonesia, namely language, social (including culture and economics in social science learning ), religious, and literacy.

Gut Microbiome Diversity and Composition in Captive Siberian Tigers (Panthera tigris altaica): The Influence of Diet, Health Status, and Captivity on Microbial Communities

The gut microbiome is essential for the health of carnivorous mammals, including the endangered Siberian tiger (Panthera tigris altaica). However, limited research exists on the gut microbiome of captive Siberian tigers, especially regarding how diet and health status influence microbial diversity. This study addresses this gap by investigating the gut microbiome diversity and composition of six captive-born Siberian tigers housed at the Baekdudaegan National Arboretum in South Korea, using 16S rRNA gene sequencing. The study aimed to examine how diet and health status influence microbial communities, providing baseline data for managing captive tigers. Alpha diversity analysis revealed significant variation in microbial richness and evenness, with Tigers 2 and 6 exhibiting the highest microbial diversity and Tiger 3 the lowest, likely due to its surgical history and limited diet. Beta diversity analysis showed distinct microbial community structures influenced by diet and health. Taxonomic profiling identified Firmicutes and Bacteroidota as the dominant phyla, with Clostridium sensu stricto more prevalent in healthier tigers, while Escherichia-Shigella and Proteobacteria were abundant in tigers with lower diversity, suggesting dysbiosis. Comparisons with other tiger species confirm that diet, health, and captivity significantly shape the gut microbiome. These findings highlight the need for personalized health management in captive environments.

‘State Brokerage’ in Migration Infrastructure: A Case of State-Led Multilevel Governance of the Employment Permit System in South Korea

This paper examines ‘state brokerage’ in migration infrastructure through South Korea's Employment Permit System (EPS). It introduces the concept of state-led multilevel governance (sMLG)—a synthesis of multilevel governance (MLG) and state transformation (ST)—as a framework for understanding state brokerage, thereby contributing to the greater diversity in migration infrastructure scholarship. By analyzing state archival documents, the paper examines how South Korean state has developed a governance framework that spans multiple political-territorial boundaries through state transformation. The transformation encompasses forging diplomatic relationships with foreign governments and orchestrating cross-border policy collaborations as well as (re)arranging domestic governance by establishing new institutions, enacting and revising laws, and reconfiguring the relationships among these entities. These processes have allowed the EPS to facilitate the migration of less-skilled labor without the involvement of private actors.

Uncovering the role of English language teaching coursebooks in safeguarding intangible cultural heritage / Explorando el rol de los libros de texto de inglés para salvaguardar el patrimonio cultural inmaterial

UNESCO and local organizations raise concern over the threats towards Intangible Cultural Heritage (ICH) and continue their efforts to get help from any field possible for introducing ICH elements and raising awareness. Education is one of those fields. Considering the relation between culture and English language teaching, ICH can be incorporated into English classrooms. Besides, being the primary source of input in a language classroom, ELT coursebooks can serve as a bearer of culture. In this regard, this paper discusses the role of English language teaching coursebooks in the safeguarding of ICH by revealing the representation of ICH elements in locally produced coursebooks from 16 different countries: Bulgaria, Chile, China, Colombia, Croatia, Germany, India, Indonesia, Japan, Malaysia, Norway, Republic of Korea, Romania, Türkiye, Ukraine and Uzbekistan. Findings from the study supported the idea that ELT coursebooks can be utilized as a medium for safeguarding ICH while improving the learners’ language skills.

Health-Promoting Behaviors, Physical Self-Efficacy, Exercise Adherence, and Sports Commitment Among Older Adults Who Participate in Sports Activities

Objectives: The Republic of Korea is progressively becoming a super-aged society, emphasizing the need for regular physical activity among older adults because it has physical, psychological, and social benefits. Recently, increasing depression and suicide rates have been reported among older adults living alone. However, research that considers older adults’ living situations is limited. Therefore, this study aimed to analyze the relationship between health-promoting behaviors (HPB), physical self-efficacy (PSE), exercise adherence, and sports commitment among older adults aged ≥ 65 years who participated in sports activities and investigate the influence of their living situation. Methods: The participants were 452 individuals aged ≥ 65 who lived in the metropolitan areas of Chungcheong-do, Jeolla-do, and Gwangju Provinces, Republic of Korea, and who regularly participated in sports activities (men = 283, women = 169). This study was conducted from January to May 2024. Data were collected using a structured and validated questionnaire, and the collected data were analyzed using descriptive statistics, correlation analysis, structural equation modeling, and multi-group analysis. Results: Structural equation modeling showed that the research model was appropriate, and all five paths showed statistical significance. The identity of the model was verified in the multi-group analysis, but path coefficients differed between older adults living alone and those living with family members. HPB significantly affected PSE, exercise adherence, and sports commitment among both groups of older adults. However, the impact of PSE on exercise adherence and sports commitment was not statistically significant among older adults living alone. Conclusions: The results highlight the need to consider older adults’ living situations when establishing regular physical activity. Efforts should also be made to promote regular exercise participation among older adults living alone.

The effect of biocide chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT) mixture on C2C12 muscle cell damage attributed to mitochondrial reactive oxygen species overproduction and autophagy activation

ABSTRACT The mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one (CMIT/MIT) is a biocide widely used as a preservative in various commercial products. This biocide has also been used as an active ingredient in humidifier disinfectants in South Korea, resulting in serious health effects among users. Recent evidence suggests that the underlying mechanism of CMIT/MIT-initiated toxicity might be associated with defects in mitochondrial functions. The aim of this study was to utilize the C2C12 skeletal muscle model to investigate the effects of CMIT/MIT on mitochondrial function and relevant molecular pathways associated with skeletal muscle dysfunction. Data demonstrated that exposure to CMIT/MIT during myogenic differentiation induced significant mitochondrial excess production of reactive oxygen species (ROS) and a decrease in intracellular ATP levels. Notably, CMIT/MIT significantly inhibited mitochondrial oxidative phosphorylation (Oxphos) and reduced mitochondrial mass at a lower concentration than the biocide amount, which diminished the viability of myotubes. CMIT/MIT induced activation of autophagy flux and decreased protein expression levels of myosin heavy chain (MHC). Taken together, CMIT/MIT exposure produced damage in C2C12 myotubes by impairing mitochondrial bioenergetics and activating autophagy. Our findings contribute to an increased understanding of the underlying mechanisms associated with CMIT/MIT-induced adverse skeletal muscle health effects.

Classification of risk levels for snow damage estimation considering socioeconomic factors in South Korea

In South Korea, the snowy season spans from October to April, and the annual average snowfall varies significantly depending on specific regions, latitudes, and elevations, ranging from 0 to 260 cm. The average annual snowfall in South Korea is 25.1 cm. Despite of the relatively shallow snowfall depth, over the past decade, South Korea has experienced approximately 120 million dollars in damages attributed to snow-related incidents. In this study, the DPSIR (Driver-Pressure-State-Impact-Response) framework was employed to consider the meteorological and socioeconomic factors to calculate the snow damage vulnerability. A total of 17 indicators were taken into account to comprehend meteorological conditions, socioeconomic factors, and historical damage records from 1994 to 2020. However, due to the limited availability of meteorological observatories and changes in greenhouse design standards, accurately estimating the snow damage amount poses challenges. Therefore, based on the vulnerability, the risk levels were classified into four categories and estimated snow damage generated by the categorized models was compared with those of the model constructed using the entire dataset. The categorized models offer improved estimation results, as the meteorological and socioeconomic characteristics within each category differ and should be addressed separately in modeling. Among the categorized models, the Green zone exhibited the best results, primarily because it did not include outlier snow damage incidents. The developed model in this study could be utilized to mitigate the impact of heavy snowfall and prioritize snow removal regions.

Premature Cognitive Commitment between Divorced Mothers and Daughters in the Early 2000s in South Korea: A Qualitative Study from the Daughters’ Perception

This study explored the premature cognitive commitments of divorced mothers and their daughters toward each other in South Korea in the early 2000s from the daughters’ perception. I conducted in-depth interviews with nine adult women who experienced parental divorce in childhood during the 2002–2004 period, revealing certain premature cognitive commitments that divorced mothers and their daughters had toward each other, such as “I can’t let my mom see that I’m struggling!” and “My daughter comes home late or stays out overnight to hang out with friends owing to her father’s absence.” Based on my findings, I discuss potential implications for counseling divorced families.

Pathways Linking Acculturation Profiles to Health Trajectories of Married Immigrant Women in South Korea

This study investigated the health trajectories of married immigrant women in South Korea and examined the mediating role of psychosocial resources in linking acculturation profiles to health trajectories. A sample of 1635 mothers who participated in the Multicultural Adolescents Panel Study was examined. The results identified three distinct health trajectories, that is, high-stable, decrease-from-high, and low-stable. In addition, three acculturation profiles (maladaptive, Korean-oriented bicultural, and undifferentiated) indirectly predicted health class through self-esteem and social network. Specifically, self-esteem mediated the path from the maladaptive and Korean-oriented bicultural profiles to a stable-low health class. Further, social networks mediated the effect of the Korean-oriented bicultural profile on the decrease from the high health class. These findings highlight the heterogeneity of married immigrant women’s health and suggest the importance of considering the relationship between individual acculturation profiles and psychosocial resources to promote the health of married immigrant women.

Effect of Offshoring on Exports of Firms in South Korea

This study empirically investigates the export-magnification effect of offshoring using a firm-level panel dataset from the manufacturing sector in South Korea. It estimates the impact of offshoring activities on export performance by examining intra-firm and arm’s length offshoring. The empirical evidence demonstrates the export-magnification effect of offshoring on both export market participation and export intensity. Particularly, the export-magnification effect of offshoring still exists among export entrants switching from non-exporters to exporters. Moreover, a greater export-magnification effect from intra-firm offshoring than from arm’s length offshoring is found using instrumental variable (IV) Tobit and probit models. This indicates that the vertical integration of production processes through intra-firm offshoring has a greater effect on export performance than international outsourcing to third parties.

Unmet Dental Care Needs of The Low-Income Elderly in South Korea: Applying the Andersen behavioural model.

Retirement reduces income and increases dental care needs for the elderly, but there are few studies on unmet dental care needs among the low-income elderly. This study aimed to identify actors associated with unmet dental care needs of low-income elderly people in South Korea. Secondary analysis of 2020 KNHANES data relating to 1,016 elderly individuals (65+) below median income. Unmet dental care needs were higher for women at 28.9% (p ⟨0.001), those with a middle school education at 28.5% (p ⟨ 0.05), individuals who rated their health as "poor" at 31.3%, those reporting feelings of depression at 44.8% (p ⟨ 0.001), individuals who rated their oral health as "poor" at 36.2% (p ⟨ 0.001), and those who experienced toothache at 37.2% (p ⟨ 0.001). In regression analysis women (Risk Ratio = 1.59, 95% CI 1.09-2.32), people with depression (RR = 2.29, 95% CI 1.01-5.15), those who perceived their oral health as "poor" (3.20, 95% CI 1.90-5.32) and those toothache (1.88, 95% CI 1.27-2.76) had higher unmet dental needs. Substantial unmet dental care needs exist among the low-income retired elderly. Comprehensive public oral health policies and community programs are needed for this population group.

A Fuzzy-Logic-Based Approach for Eliminating Interference Lines in Micro Rain Radar (MRR-2)

This research presents a novel fuzzy-logic-based algorithm aimed at detecting and removing interference lines from Micro Rain Radar (MRR-2) data. Interference lines, which are non-meteorological echoes with unknown origins, can severely obscure meteorological signals. Leveraging an understanding of interference line characteristics, such as temporal continuity, we identified and utilized eight key variables to distinguish interference lines from meteorological signals. These variables include radar moments, Doppler spectrum peaks, and the spatial/temporal continuity of Doppler velocity. The algorithm was developed and validated using data from MRR installations at three sites (Seoul, Suwon, and Incheon) in South Korea, from June to September 2021–2023. While there is a slight tendency to eliminate some weak precipitation, results indicate that the algorithm effectively removes interference lines while preserving the majority of genuine precipitation signals, even in complex scenarios where both interference and precipitation signals are present. The developed software, written in Python 3 and available as open-source, outputs in NetCDF4 format, with customizable parameters for user flexibility. This tool offers a significant contribution to the field, facilitating the accurate interpretation of MRR-2 data contaminated by interference.

A new species of Merismomorpha Girault, 1913 (Chalcidoidea, Pteromalidae) from the Palaearctic region

A new species of Merismomorpha Girault, 1913, M. ulleungensis Tselikh, Rasplus &amp; Ku, sp. nov., is described and illustrated from the Palaearctic region (Russian Far East and South Korea). An updated diagnosis of the genus is given, as well as a comparison to the closely related genus Pterosemopsis Girault, 1917.

Message from the Editor-in-Chief

The IJHE continues to be the choice of journal for many global researchers. As such, the strength of the IJHE journal is reflected in this issue’s five research articles from Canada, South Korea and Saudi Arabia. This issue has a strong focus on improving the online curriculum and learning space for students. Global events continue to dominate media outlets and present everyday challenges for some with seemingly no end or resolve. With significant political change in the air, it is important that we continue to prioritise education and lifelong learning, researching areas that will improve educational access and strategies for success. The IJHE provides an important platform for the development of theory, the addressing of policy questions, and the dissemination of innovative practice in the field of tertiary education, specifically widening participation and lifelong learning.