Cycling safely: Examining the factors associated with bicycle accidents in Seoul, South Korea.

This study investigates the factors contributing to bicycle accidents, focusing on four types of bicycle lanes and other exposure and built environment characteristics of census blocks. Using Seoul as a case study, three years of bicycle accident spot data from 2018 to 2020 was collected, resulting in 1,330 bicycle accident spots and a total of 2,072 accidents. The geographically weighted Poisson regression (GWPR) model was used as a methodological approach to investigate the spatially varying relationships between the accident frequency and explanatory variables across the space, as opposed to the Poisson regression model. The results indicated that the GWPR model outperforms the global Poisson regression model in capturing unobserved spatial heterogeneity. For example, the value of deviance that determines the goodness of fit for a model was 0.244 for the Poisson regression model and 0.500 for the far better-fitting GWPR model. Further findings revealed that the factors affecting bicycle accidents have varying impacts depending on the location and distribution of accidents. For example, despite the presence of bicycle lanes, some census blocks, particularly in the northeast part of the city, still pose a risk for bicycle accidents. These findings can provide valuable insights for urban planners and policymakers in developing bicycle safety measures and regulations.

Predictive Geogenic Radon Potential (P-GRP): A novel approach for comprehensive hazard assessment and risk modeling in subsurface environment.

Geogenic radon potential (GRP) is traditionally used for mapping radon-prone areas. However, this has challenges in the accurate assessment of radon risk because of limitations such as oversimplified soil measurements and lack of geological profiles. This study presents predictive geogenic radon potential (P-GRP), integrating geological characterization and advanced modeling for the emanation and transport of radon in the subsurface environment. Seoul, South Korea, was selected as the research area for the evaluation of hazards using P-GRP, while subway station A was selected for the assessment of indoor health risks. The geology was characterized by the layers of bedrock and soil using uranium contents and porosity. The emanation of radon was modeled considering the radioactive decay chain of uranium and the pore structures. The vertical transport of radon was modeled considering the porosity variation within geological media, which was used for the calculation of P-GRP. Without loss of continuity, the P-GRP map was constructed by calculating P-GRP at a specific depth over the Seoul area. The calculation of P-GRP in the case of subway station A demonstrates that the radon concentration in the bedrock at the platform depth was expected to be 382 million Bqm-3. The indoor radon risk was calculated using the P-GRP by coupling the vapor intrusion process. This presented a high cancer risk for the employees as well as commuters. The P-GRP map of Seoul demonstrated higher hazards in granite zones compared to banded gneiss zones. These results have demonstrated that the P-GRP could be a novel and promising approach for assessing hazard and risk by geogenic radon during subsurface development.

Residential mobility according to health status in South Korea's largest metropolitan city during the COVID-19 pandemic using generalized estimating equations for longitudinal data.

This study examines whether residential mobility differed according to health status in Seoul, the largest metropolitan city in South Korea, during the COVID-19 pandemic. Before the COVID-19 pandemic, people who moved had better health status in the baseline year than those who did not. However, during the pandemic, the residential mobility of people with poor health status increased, particularly in 2019-2020. This pattern appeared to be driven by the 55-74 age group. The effect of health status on residential mobility was not attenuated, even after adjusting for covariates at multiple levels.

The April Revolution and the Sense of Place in Medical Space: Focusing on Major Hospitals in Downtown Seoul.

This article focuses on the medical activities conducted by major hospitals in downtown Seoul during the April Revolution in 1960, examining their experiential context and significance. The influx of guns and bullets into Korean society following the liberation in 1945 intertwined with the political and social conflicts of the period, resulting in numerous assassinations, crimes, and terrorism. Gunshot wounds were traumas that became a part of the everyday life of Koreans, as well as scars which reflected their historical contexts. At the same time, the frequent occurrence of gunshot wounds led to the development of medical capacities to treat them. The Korean surgical academia expanded its technical foundation with experiences during and after the Korean War. This progress was particularly noticeable in areas closely related to gunshot wounds, such as craniotomy, thoracotomy, vascular anastomosis, debridement, anesthesia, and blood transfusion. Major hospitals in downtown Seoul served as medical spaces where these experimental and technical foundations were concentrated, allowing them to minimize the death toll despite the massive gunfire by the National Police in April 1960. Thus, the aftermath of the epidemic of gunshots resulted in a rather paradoxical outcome. This development became a resource for doctors and nurses, who added their revolutionary implications in reconstructing the experience of April 1960 in their various memoirs and reports. While memoirs reorganized general medical activities, portraying injured patients as participants in the revolution, reports provided forensic descriptions and interpretations of the deaths, giving authority to the main narrative of the revolution. As the interpretations and significance based on historical contexts gained prominence, major hospitals in downtown Seoul also developed a sense of place closely associated with the revolution.

Temporal pattern classification of PM2.5 chemical compositions in Seoul, Korea using K-means clustering analysis.

Particulate matter with a diameter ≤ 2.5 µm (PM2.5) is a complex mixture of particles with a variety of compositions potentially including sulfate ions (SO42-), nitrate ions (NO3-), ammonium ions (NH4+), organic and inorganic elemental carbon, and metals. Here, the temporal composition evolution of PM2.5 was analyzed to characterize its emission source, origin, and external influences. The concentrations of wintertime PM2.5 chemical compositions in Seoul, Korea during the period of 2012-2021 were classified into four representative clusters using a K-means cluster analysis method. Cluster 1 exhibited high concentrations of NO3- and NH4+ ions mainly due to the prevalence of emissions from domestic manure and fertilizer sources in the northeast. High concentrations of these two ions are conducive to generation of ammonium nitrate (NH4NO3) through atmospheric chemical reactions, resulting in relatively long-lasting high PM2.5 concentrations in Seoul. In cluster 2, high concentrations of SO42-, vanadium, and nickel were observed in frequent south-westerly winds, indicating the domestic influence of industrial facilities. Cluster 3 showed high concentrations of potassium ions and organic carbon, highlighting a pronounced external influence transported from China via prevailing westerly winds. Cluster 4 showed low PM2.5 concentrations accompanied by strong winds in warm environments, which are uncommon in winter. This study revealed that the air quality in Seoul, which was influenced by many factors, could be classified into four representative patterns. Our results provide insights into the emission sources, major influences, and responsible mechanisms of high PM2.5 concentrations in Seoul, which can help with air quality policies.

Implications of PM2.5 chemical composition in modulating microbial community dynamics during spring in Seoul.

Particulate matter with an aerodynamic diameter of 2.5 µm or less (PM2.5) harbors a diverse microbial community. To assess the ecological dynamics and potential health risks associated with airborne microorganisms, it is crucial to understand the factors influencing microbial communities within PM2.5. This study investigated the influence of abiotic parameters, including air pollutants, PM2.5 chemical composition (water-soluble ions and organics), and meteorological variables, on microbial communities in PM2.5 samples collected in Seoul during the spring season. Results revealed a significant correlation between air pollutants and water-soluble ions of PM2.5 with microbial α-diversity indices. Additionally, air pollutants exerted a dominant effect on the microbial community structure, with stronger correlations observed for fungi than bacteria, whereas meteorological variables including temperature, pressure, wind speed, and humidity exerted a limited influence on fungal α-diversity. Furthermore, the results revealed specific water-soluble ions, such as SO42-, NO3-, and NH4+, as important factors influencing fungal α-diversity, whereas K+ negatively correlated with both microbial α-diversity. Moreover, PM2.5 microbial diversity was affected by organic compounds within PM2.5, with fatty acids exhibited a positive correlation with fungal diversity, while dicarboxylic acids exhibited a negative correlation with it. Furthermore, network analysis revealed direct links between air pollutants and dominant bacterial and fungal genera. The air pollutants exhibited a strong correlation with bacterial genera, such as Arthrospira and Clostridium, and fungal genera, including Aureobasidium and Cladosporium. These results will contribute to our understanding of the ecological dynamics of airborne microorganisms and provide insights into the potential risks associated with PM2.5 exposure.

When and why PM2.5 is high in Seoul, South Korea: Interpreting long-term (2015-2021) ground observations using machine learning and a chemical transport model.

Seoul has high PM2.5 concentrations and has not attained the national annual average standard so far. To understand the reasons, we analyzed long-term (2015-2021) hourly observations of aerosols (PM2.5, NO3-, NH4+, SO42-, OC, and EC) and gases (CO, NO2, and SO2) from Seoul and Baekryeong Island, a background site in the upwind region of Seoul. We applied the weather normalization method for meteorological conditions and a 3-dimensional chemical transport model, GEOS-Chem, to identify the effect of policy implementation and aerosol formation mechanisms. The monthly mean PM2.5 ranges between about 20 µg m-3 (warm season) and about 40 µg m-3 (cold season) at both sites, but the annual decreasing rates were larger at Seoul than at Baengnyeong (-0.7 µg m-3 a-1 vs. -1.8 µg m-3 a-1) demonstrating the effectiveness of the local air quality policies including the Special Act on Air Quality in the Seoul Metropolitan Area (SAAQ-SMA) and the seasonal control measures. The weather-normalized monthly mean data shows the highest PM2.5 concentration in March and the lowest concentration in August throughout the 7 years with NO3- accounting for about 40 % of the difference between the two months at both sites. Taking together with the GEOS-Chem model results, which reproduced the elevated NO3- in March, we concluded the elevated atmospheric oxidant level increases in HNO3 (which is not available from the observation) and the still low temperatures in March promote rapid production of NO3-. We used Ox (≡ O3 + NO2) from the observation and OH from the GEOS-Chem as a proxy for the atmospheric oxidant level which can be a source of uncertainty. Thus, direct observations of OH and HNO3 are needed to provide convincing evidence. This study shows that reducing HNO3 levels through atmospheric oxidant level control in the cold season can be effective in PM2.5 mitigation in Seoul.

Exploring the Genetic Diversity and Molecular Evolution of Seoul and Hantaan Orthohantaviruses.

Seoul (SEOV) and Hantaan (HTNV) orthohantaviruses are significant zoonotic pathogens responsible for hemorrhagic fever with renal syndrome. Here, we investigated the molecular evolution of SEOV and HTNV through phylogenetic and bioinformatic analyses using complete genome sequences of their large (L), medium (M), and small (S) gene segments. Despite similar epizootic cycles and clinical symptoms, SEOV and HTNV exhibited distinct genetic and evolutionary dynamics. The phylogenetic trees of each segment consistently showed major genetic clades associated with the geographical distribution of both viruses. Remarkably, SEOV M and S segments exhibit higher evolutionary rates, rapidly increasing genetic diversity, and a more recent origin in contrast to HTNV. Reassortment events were infrequent, but both viruses appear to utilize the M gene segment in genetic exchanges. SEOV favors the L or M segment reassortment, while HTNV prefers the M or S segment exchange. Purifying selection dominates in all three gene segments of both viruses, yet SEOV experiences an elevated positive selection in its glycoprotein Gc ectodomain. Key amino acid differences, including a positive 'lysine fence' (through residues K77, K82, K231, K307, and K310) located at the tip of the Gn, alongside the physical stability around an RGD-like motif through M108-F334 interaction, may contribute to the unique antigenic properties of SEOV. With the increasing global dispersion and potential implications of SEOV for the global public health landscape, this study highlights the unique evolutionary dynamics and antigenic properties of SEOV and HTNV in informing vaccine design and public health preparedness.

Impact of ozonation on the formation of particulate nitrosodi-methylamine (NDMA) in atmosphere.

The contribution of ozonation to the formation of particulate nitrosodi-methylamine (NDMA) in the aqueous aerosol phase was investigated using measurement data from 2018 in Seoul, Republic of Korea and a box model. The correlation between the NDMA concentration and aerosol liquid water content and box model results showed that aqueous aerosol phase reactions, including nitrosation and ozonation, might contribute to the formation of NDMA. The concentration of NDMA and the ratio of O3/dimethylamine exhibited a negative correlation, suggesting that the contribution of ozonation to NDMA formation may not be significant. Furthermore, when the daily concentration of NDMA exceeded 10 ng/m3, the pH was 3.96 ± 0.48, indicating that the impact of ozonation on NDMA concentration might not be significant. To quantitatively investigate the contribution of ozonation, the ozonation mechanism that forms NDMA was included in the box model developed in our previous study. The model results showed that the ozonation contributed to the ambient concentration of NDMA (7.9 ± 3.8% (winter); 1.9 ± 3.0% (spring); 10.0 ± 0.77% (summer); 3.6 ± 7.3% (autumn)). It is estimated that the relatively higher O3/NOx ratio in summer (1.63 ± 0.69; 0.64 ± 0.52 (winter); 1.14 ± 0.92 (spring); 0.52 ± 0.54 (autumn)) could enhance ozonation and that relatively lower pH in summer (2.2 ± 0.4; 5.3 ± 1.2 (winter); 3.9 ± 1.2 (spring); 3.9 ± 0.7 (autumn)) could hinder nitrosation compared to that in other seasons.

Hantavirus Disease Cluster Caused by Seoul Virus, Germany.

A cluster of 3 persons in Germany experienced hantavirus disease with renal insufficiency. Reverse transcription PCR-based genotyping revealed infection by Seoul hantavirus transmitted from pet rats. Seoul virus could be responsible for disease clusters in Europe, and infected pet rats should be considered a health threat.

The level of food literacy and its association with food intake and obesity status among Seoul citizens: results from Seoul Food Survey 2021.

BACKGROUND/OBJECTIVES: Food literacy (FL) is a crucial skill for selecting sustainable and healthy food options, necessitating the identification of vulnerable groups in the community using valid measurement tools. Identifying weak domains in FL is essential for enhancing the overall FL. This study examined the FL levels of Seoul citizens based on their sociodemographic characteristics and assessed the relationship between FL, food intake, and weight status. SUBJECTS/METHODS: This study utilized the data from the Seoul Food Survey, a cross-sectional study employing representative samples of Seoul citizens. Data collection occurred from September to October 2021, with 4,039 citizens aged 18 yrs and above participating in face-to-face surveys. Thirty-three FL items were assessed, comprising 14 items in the nutrition and safety (NS) domain, eight items in the cultural and relational (CR) domain, and 11 items in the socio-ecological (SE) domain. In addition, data on food intake sufficiency and obesity status were collected. The descriptive statistics, t-tests, analysis of variance, and logistic regression analysis were used for analysis. RESULTS: Men, students, young adults, older citizens, and people experiencing food insecurity had the lowest scores for all the FL domains. The highest quartile group of NS scores had a higher probability of consuming adequate servings of vegetables and fruits, with significant linear trends observed (P for trend < 0.05). In all three FL domains, the odds ratio for obesity was significantly lower in the groups with high FL scores (P < 0.05). CONCLUSIONS: A close relationship was observed between low FL, obesity, and food intake, even after controlling for other covariates. Vulnerable groups with low FL were also identified. Therefore, it is essential to develop programs to improve FL and the health and well-being of these groups.

Genetic diversity and molecular evolution of Seoul virus in Hebei province, China.

Seoul virus (SEOV) is a major pathogen which causes hemorrhagic fever with renal syndrome (HFRS), and is present all over the world. However, there are currently few long-term systematic studies of SEOV's phylogenetic and evolutionary mechanisms in epidemic areas. Thus, in this study, we used RT-PCR combined with NGS to obtain the genomes of six SEOV viruses from 1993, as well as 56 Hebei province-specific tissue samples from 1999 to 2022. Phylogenetic analysis showed that the SEOV samples could be divided into seven groups and showed geographic clustering. The geographic region may be the main factor affecting the genetic diversity of SEOV. We also found that SEOV was subject to strong overall purifying selection and positive selection at certain sites during evolution. Recombination events and high nucleotide substitution rates were also shown to accelerate SEOV's evolution. Evolutionary feature of the L segment is more representative of complete genome. Our detailed analysis provides a deeper understanding of the genetic diversity and evolutionary drivers of SEOV within its primary epidemic areas. It will be important to further monitor epidemiological trends and drivers of variation to help increase our understanding of the pathogenicity of SEOV infections.

Ineffective implementation of emergency reduction measures against high concentrations of particulate matter in Seoul, Republic of Korea.

Since December 30, 2017, the Seoul Metropolitan Government, Republic of Korea, has been implementing emergency reduction measures (ERMs) restricting the operation of industrial sites, thermal power plants, and vehicles when air quality is expected to deteriorate. ERMs are implemented when the present observed concentration of particulate matter (PM) of aerodynamic diameter less than 2.5 µm (PM2.5) and/or the predicted values for the following day exceed a threshold value. In this study, the effectiveness of ERMs was evaluated for 33 days with and 6 days without ERM implementation but where the PM2.5 concentration exceeded the threshold value, until March 15, 2021. Of the 33 days of ERM implementation, on 7 days it was executed despite the thresholds not being met. The ERM on these days might have been properly executed because the pre-notice and implementation of ERM might have reduced the local emissions of air pollutants. Our major findings are that even on days of ERM implementation, there were marginal reductions in vehicle traffic, thermal power generation, and industrial emissions. Second, the concentrations of PM2.5 and related air pollutants in Seoul were almost unchanged for most ERM implementation episodes. Third, most of the 39 (= 33 + 6) days when the air quality worsened were caused by the transboundary transport of air pollutants from China. In conclusion, it was revealed that the currently executed ERM law is insufficient for effectively reducing PM2.5. To achieve the required reductions, it is necessary to undertake stricter policies in Seoul and its neighboring regions.

Co-circulation and co-infection of hantaviruses and Wenzhou mammarenavirus in small mammals and humans in Jiangxi, China.

Both Orthohantaviruses (HV) and Whenzhou Mammarenaviruses (WENV) are rodents borne viruses, allowing them to spread simultaneously in the same area and infect humans. To explore the potential threat of HV and WENV to public health safety, an environmental and laboratory investigation was conducted in 2020-2021, in Jiangxi province, China. A total of 461 small mammals of 7 species and paired sera from 43 suspected HFRS cases were collected from Jiangxi Province, China. Viral genomic RNA and specific antibodies against HV and WENV were detected to evaluate the epidemic situation of the two viruses. Hantaan virus (HTNV), seoul virus (SEOV) and WENV RNA were detected in the lungs of the captured mammals, which resulted 4.1% and 7.4% of HV and WENV RNA positive respectively. Co-infections of WENV and SEOV were detected from Rattus norvegicus, Mus musculus and Rattus flavipectus with an overall co-infection rate of 0.65%. The detection rates of antibodies in the blood against HV and WENV were 11.9% (55/461), and 13.2% (61/461) respectively. The prevalence of viral infection and viral genetic characters varied among the selected areas. In the paired sera of 43 suspected HFRS cases, 38 were with HV infection, 11 were with WENV IgG, and 7 with a 4-fold or more of WENV IgG titer elevation. These results revealed the fact of the co-circulating and coinfection of HV and WENV in the same area at the same time, which might impact on public health safety.

Evaluating planting strategies for outdoor thermal comfort in high-rise residential complexes: a computational fluid dynamics simulation study.

This study aims to examine the impact of planting strategies on improving thermal comfort in relation to the existing buildings within real high-rise residential complexes. Using numerical simulation via ENVI-met, we compare six planting scenarios characterized by two locational schemes-open-space planting and building-vicinity planting-and three tree quantities. The results highlight the importance of planting greater numbers of trees, and also of their locations, to moderate the thermal environment. The findings of the study demonstrated that increasing the number of trees in the open space by threefold of the advisory guidelines led to a significant reduction in the average air temperature by 0.87 °C, mean radiant temperature (MRT) by 11.00 °C, physiological equivalent temperature (PET) by 4.50 °C, and wind speed by 0.30 m/s. Planting the minimum number of trees under building-vicinity reduced air temperature by 0.07 °C, MRT by 2.48 °C, and PET by 0.92 °C, while showing a slight increase in wind speed of approximately 0.01 m/s. To achieve improvements in both thermal condition and air flow, we suggest planting rows of trees parallel to the prevailing wind direction in the ventilation corridors at some distance from buildings, to minimize overlap of shade from trees and from buildings. The findings of this study will provide useful guidelines for effective planting design in dense residential areas.

Dosimetric assessment in the brain for downlink EMF exposure in Korean mobile communication networks.

Because the position and direction of the human body is not fixed in an actual environment, the incidence direction of the electromagnetic field (EMF) from mobile communication base stations, WiFi access points, broadcasting towers, and other far-field sources is arbitrary. To analyze the overall health effects of radio frequency EMF exposure, the dosimetric assessment for such environmental exposures created from an unspecified number of sources in daily life, along with exposures from specific EMF sources, must be quantified. This study is aimed at numerically evaluating the time-averaged specific absorption rate (SAR) of the human brain for environmental EMF exposure in the frequency range of 50-5800 MHz. Whole-body exposure to EMFs that are evenly incident spatially is considered. By comparing the results of several incidence directions and the number of polarizations, an optimal calculation condition has been derived. Finally, based on the results measured in Seoul at the end of 2021, the SAR and daily specific energy absorption (SA) in the brains of both a child and an adult for downlink exposures from 3G to 5G base stations are reported. Comparison results of the daily brain SA for exposure to DL EMF in all 3G to 5G mobile networks and exposure to a 10-min voice call (uplink EMF) using a mobile phone connected to a 4G network show that the SA from the downlinks is much higher than that from the uplinks.

A Development of Rapid Whole-Genome Sequencing of Seoul orthohantavirus Using a Portable One-Step Amplicon-Based High Accuracy Nanopore System.

Whole-genome sequencing provides a robust platform for investigating the epidemiology and transmission of emerging viruses. Oxford Nanopore Technologies allows for real-time viral sequencing on a local laptop system for point-of-care testing. Seoul orthohantavirus (Seoul virus, SEOV), harbored by Rattus norvegicus and R. rattus, causes mild hemorrhagic fever with renal syndrome and poses an important threat to public health worldwide. We evaluated the deployable MinION system to obtain high-fidelity entire-length sequences of SEOV for the genome identification of accurate infectious sources and their genetic diversity. One-step amplicon-based nanopore sequencing was performed from SEOV 80-39 specimens with different viral copy numbers and SEOV-positive wild rats. The KU-ONT-SEOV-consensus module was developed to analyze SEOV genomic sequences generated from the nanopore system. Using amplicon-based nanopore sequencing and the KU-ONT-consensus pipeline, we demonstrated novel molecular diagnostics for acquiring full-length SEOV genome sequences, with sufficient read depth in less than 6 h. The consensus sequence accuracy of the SEOV small, medium, and large genomes showed 99.75-100% (for SEOV 80-39 isolate) and 99.62-99.89% (for SEOV-positive rats) identities. This study provides useful insights into on-site diagnostics based on nanopore technology and the genome epidemiology of orthohantaviruses for a quicker response to hantaviral outbreaks.

Changes in public bike usage after the COVID-19 outbreak: A survey of Seoul public bike sharing users.

When the COVID-19 pandemic swept across the world, people tended to seek more individualized and viable transportation modes, such as a bicycle. In this study, we examined the factors influencing changes in public bike sharing (PBS) in Seoul, to assess this trend post-pandemic. We conducted an online survey of 1,590 Seoul PBS users between July 30 and August 7, 2020. Using a difference-in-differences analysis, we found that participants who were affected by the pandemic used PBS 44.6 h more than unaffected individuals throughout the year. In addition, we used a multinomial logistic regression analysis to identify the factors affecting changes in PBS usage. In this analysis, the discrete dependent variables of increased, unchanged, and decreased were considered, representing the changes in PBS usage after the COVID-19 outbreak. Results revealed that PBS usage increased among female participants during weekday trips such as commuting to work and when there were perceived health benefits of using PBS. Conversely, PBS usage tended to decrease when the weekday trip purpose was for leisure or working out. Our findings offer insight into PBS user behaviors within the context of the COVID-19 pandemic and present policy implications to revitalize PBS usage.

Determination of heavy metals and risk assessment in nail cosmetics sold in Seoul, Korea.

OBJECTIVE: The objective of this study was to evaluate some toxic levels of nail cosmetics marketed in Seoul, Korea and health risk assessment on humans. METHODS: We collected 45 random nail cosmetics and analysed for lead, cadmium, arsenic and antimony by inductively coupled plasma-optical emission spectrometry (ICP-OES). RESULTS: Four metals concentrations were Pb 0.037 ± 0.083 (

Sodium intake trend and current intake level by meal provision place among the citizens of Seoul.

BACKGROUND/OBJECTIVES: The diversity of meal provision places has increased in recent years and sodium intake can vary depending on where meals are eaten, particularly in large cities. In this study, an analysis of the recent trends in sodium intake was performed and a comparison of sodium intake level according to meal provision place among citizens of Seoul was performed. SUBJECTS/METHODS: Data from a 24-h recall dietary intake survey from the 2010-2019 Korea National Health and Nutrition Examination Survey (KNHANES) were used in order to determine the trends in sodium intake among citizens of Seoul, aged 3-74 years old. (n = 11,811). The trend of daily sodium intake was presented in absolute amount and proportion compared to the chronic disease risk reduction intake (CDRR) for each selected characteristic. A comparison of sodium intake level according to meal provision place by sex and age groups as a total amount per meal (mg), density per meal (mg/1,000 kcal), and proportion of the daily sodium intake was performed using the 2016-2019 KNHANES. RESULTS: Sodium intake levels showed a downward trend from 2010-2019. The highest level of sodium intake was observed for subjects aged 30-49, and the level for males aged 30-49 was 202.8% higher than the CDRR. Results of the analysis of sodium intake per meal according to meal provision place showed that the highest sodium intake was in the order of restaurant meal (RM) > institutional foodservice (IF) > home meal (HM) > convenience food (CF). A higher sodium density (mg/1,000 kcal) was observed for IF compared with RM in most adults. Adults aged over 50 years old consumed more than half of the daily sodium in HM. CONCLUSION: Significant variation in the level of sodium intake was observed according to sex and age groups, therefore, different approaches and nutrition policies based on meal provision place are needed.