This study improved the analytical performance of 28 PFAS, including ultra-short-chain (USC) PFAS, and assessed their distribution in the Namhangang River. Optimization of the online SPE column and mobile-phase conditions markedly enhanced the peak intensities of USC PFAS—TFMS, PFEtS, PFPrA, and PFPrS increased by 4.9-, 13.9-, 13.0-, and 23.4-fold, respectively—allowing for reliable quantification. Using the optimized method, five monitoring surveys conducted in 2025 showed the highest PFAS concentrations at the S1 site (mean: 2,803 ng/L), where semiconductor effluent is directly discharged. PFAS concentrations consistently decreased downstream, indicating dilution as the dominant controlling factor. USC (58.9%) and short-chain PFAS (40.6%) accounted for most of the PFAS composition at the S1 site, with TFMS (47.8%) and PFPrA (51.6%) comprising the majority of the USC fraction. A very strong positive correlation was observed between the short-chain PFAS pairs PFBA–PFMPA and PFPeA–PFMBA (Spearman’s rank correlation coefficient, ρ = 1.0; p-value < 0.05), suggesting shared industrial origins and similar environmental behavior. Overall, this study strengthens the analytical reliability of USC PFAS and provides a quantitative characterization of PFAS contamination in the Namhangang River, offering essential baseline information for future PFAS monitoring and water-quality management.
This study aimed to analyze the characteristics of indoor air quality (IAQ) in facilities, particularly child care centers and elderly care facilities, used by vulnerable populations in Busan and to identify priority pollutants requiring focused management for each facility type. Based on a comprehensive analysis of pollutant concentration levels, the frequency of high-concentration episodes, exceedance rates of IAQ maintenance standards, and environmental influencing factors, PM-2.5 was identified as the priority pollutant in elderly care facilities, whereas carbon dioxide (CO2) and total airborne bacteria (TAB) were determined to be the pollutants requiring priority management in child care centers. Although PM-2.5 is largely influenced by outdoor air quality, cases of high indoor PM-2.5 concentrations suggest the potential presence of additional indoor sources in addition to outdoor air infiltration. CO2 and TAB concentrations tended to increase in indoor spaces with higher occupancy density and elevated indoor temperatures, indicating that indoor sources were the dominant contributors. Therefore, differentiated IAQ management strategies are required for facilities used by vulnerable populations, focusing on priority pollutants that reflect the spatial and user characteristics of each facility type.
This study investigated groundwater quality and pollution sources in the northeastern Gyeonggi region, specifically Pocheon, Gapyeong, and Yangpyeong. A total of 3,749 samples collected between January 2022 and December 2024 were analyzed for 15 drinking water quality parameters, including pH, major inorganic ions, and heavy metals. Piper diagram analysis indicated that Ca-HCO3 (approximately 60%) and Ca-Mg-HCO3(approximately 30%) water types predominated, suggesting the presence of fresh groundwater. Statistical analyses using the Mann–Kendall test and Sen’s slope estimator revealed significant increasing trends in nitrate-nitrogen across all three regions (p < 0.05), with Pocheon exhibiting the highest rate of increase (0.020 mg/L/month). Pocheon also showed the highest concentrations of sulfate and chloride, attributed to intensive agricultural activities and urbanization. The NO3−-N/NH4+-N ratio indicated that 97.9% of samples exceeded 10, suggesting that chemical fertilizers are the dominant pollution source. This interpretation was supported by the Cl−/NO3−-N mass ratio, with 62.1% of samples below 5. Overall, these findings provide a scientific basis for developing region-specific groundwater management strategies to ensure the safe use and conservation of groundwater in the upper Han River basin.
This study investigated the spatial and temporal distribution of total and dissolved microcystins in recreational areas of the lower Geum River and evaluated differences according to sampling position. Water samples were collected monthly from May to October 2025 at nine shoreline sites, and cross-sectional composite samples were additionally collected at two representative sites during the cyanobacterial bloom period (August–September). Total microcystins ranged from ND to 9.878 μg/L and generally increased toward downstream sites. MC-RR was the dominant congener in total microcystins, whereas dissolved microcystins showed a relatively lower contribution of MC-RR and a higher contribution of MC-YR. Dissolved microcystins were detected at low concentrations (ND–0.091 μg/L) and exhibited limited temporal and spatial variability. Total microcystins were significantly associated with cyanobacteria, chlorophyll-a, water temperature, and pH. Comparison of shoreline and cross-sectional samples showed similar temporal trends and dominant congeners but differences in concentration levels and environmental relationships. These results indicate that shoreline observations reflect localized exposure conditions, whereas cross-sectional samples represent average river-section characteristics. The findings provide useful information for microcystin monitoring and spatial representativeness assessment in recreational river environments.
The rates of inadequacy in on-site evaluations conducted on 101 environmental test laboratories of the odor field, 15 laboratories at specialized institutions for persistent organic pollutant analysis, and 24 laboratories at environmental hazardous factor inspection agencies were analyzed. In case of the complex odor field, issues were raised regarding the management of odor analysts and odor judgment personnel, qualitative maintenance of odorless air generation devices, and appropriateness of the source odor identification process. In case of the persistent organic pollutants field, accuracy is required in the management of glassware and analytical equipment used during the analysis process as well as in the calculation of test results. In case of the environmentally hazardous factor field, improvements are needed regarding the selection of sampling points, the appropriateness of sample volume, result display, gas safety measures, and sample collection records.
This study analyzed 1,640 indoor floor dust samples collected between 2015 and 2019 as part of the “Children's Environmental Health Birth Cohort” project. The aim was to assess phthalate and alternative plasticizer contamination, their temporal trends, and the exposure implications for children. Gas chromatography/mass spectrometry (GC/MS) was used to ensure accurate quantification of the phthalates and plasticizers and the established analytical method successfully met all validation criteria for linearity, accuracy, and precision. Di(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), and dioctyl terephthalate (DOTP) were detected in 100% of samples at high average concentrations of 1670.3 mg/kg, 525.7 mg/kg, and 1462.6 mg/kg, respectively. Other alternative plasticizers (di(2-ethylhexyl) adipate, acetyl tributyl citrate, tris(2-ethylhexyl) phthalate, and diisononyl 1,2-cyclohexanedicarboxylic acid) were found at lower detection rates and concentrations. An analysis of the floor dust revealed that DEHP and DINP concentrations began to decline from 2015 onwards and this decline was concurrent with a progressive increase in DOTP levels. Monitoring phthalates and alternative plasticizers in indoor floor dust is essential when assessing child exposure risks. While alternative plasticizers were generally present at lower concentrations in dust compared to traditional phthalates, their increasing use and detection in indoor environments warrant ongoing surveillance and evaluation of their health impacts.
This study presents the first comprehensive assessment of discharge characteristics and ecological risks associated with alkylphenols, specifically nonylphenol (NP) and octylphenol (OP), in industrial wastewater across Busan, Korea. A total of 146 samples were analyzed revealing detection frequencies of 18% for NP and 54% of OP. Higher concentrations of both compounds were predominantly observed in wastewater in effluents from steel and metal processing (NP: ND[not detected] to 21.838 μg/L, OP: ND to 206.053 μg/L) and repair and car wash facilities (NP: ND to 54.039 μg/L, OP: ND to 60.564 μg/L). The OP concentrations were significantly higher than those of NP, suggesting its growing use as a replacement for NP following the stricter regulatory controls on NP. Hazard quotient (HQ) calculations revealed that NP exceeded the high-risk threshold (HQ≥1) in 4.1% of the samples, whereas OP surpassed this threshold in 28.1% of samples, underscoring its greater potential for environmental harm. Despite average removal efficiencies of 94% NP and 80% for OP in public sewage treatment plants, the persistence and ecological relevance of these compounds remain concerning. The findings emphasize the need for targeted monitoring and mitigation strategies to address alkylphenols contamination in industrial effluent.
This study developed analytical methods for quantifying 39 per- and polyfluoroalkyl substances (PFAS) and 23 pharmaceuticals in water samples using direct injection and online solid-phase extraction (online SPE) coupled with liquid chromatography–tandem mass spectrometry (LC–MS/MS). The performance of the online SPE method was compared with that of direct injection. For PFAS, online SPE achieved lower method detection limits (MDLs; 0.1794.72 ng/L) than direct injection (3.2731.3 ng/L). Similarly, for pharmaceuticals, MDLs obtained with online SPE (0.0590.314 ng/L) were lower than those from direct injection (1.0956.8 ng/L). Both methods met established analytical criteria, showing acceptable accuracy (70130%) and precision (≤20%). The optimized method was applied to water samples from the Nakdong River in Korea. Among the 39 PFAS, only one compound was detected via direct injection, whereas eight compounds were identified using online SPE. For pharmaceuticals, direct injection detected 10 compounds, while online SPE identified 15. Additionally, the detection frequency across sampling sites was similar to or higher than that of online SPE compared to direct injection. Overall, online SPE proved more effective for detecting PFAS and pharmaceuticals in river water than direct injection, offering additional advantages in labor efficiency, cost-effectiveness, and suitability for routine water quality monitoring programs.
In this study, a tall tower measurements system was established on the Boseong Tall Tower (BTT, 34.76˚N, 127.21˚E) to monitor greenhouse gases from long-range transport. The in situ measurement system uses a cavity ring-down spectroscopy (CRDS) analyzer, which continuously measures carbon dioxide (CO2) and methane (CH4) concentrations at 300 m above ground level. The system was tested during the ASIA-AQ campaign in Feb 2024. A 4-point calibration was performed for quality assurance (QA), with measurement accuracies of 0.25 ppm for CO2 and 2.0 ppb for CH4. During the study period, the average CO2 concentration was 435.98 ± 6.93 ppm, and the average CH4 concentration was 2046.1 ± 24.8 ppb. When compared with the hourly data from domestic stations, the BTT time series data showed similar concentration levels, effectively representing the inflow and outflow of greenhouse gases across the Korean peninsula. However, high CO2 concentrations were observed under specific wind directions, suggesting the need for further analysis of long-term changes in the CO2/CH4 ratio.
This study used monitoring data to analyze the PM-10 heavy metal concentrations in Jeollanam-do from 2022 to 2024. Samples were collected for 24 h over 5 d each month. The annual, seasonal, and site-specific variations in PM-10 and metal concentrations were analyzed, and the main sources and emission characteristics were identified through correlation and factor analyses. The average PM-10 concentration during the study period was 27±17 μg/m3, while the total heavy metal concentration was 1.99255±1.87673 g/m3, accounting for 7.2±5.0% of the PM-10 concentration. Fe, Ca, Al, and Mg were the dominant heavy metals, accounting for over 80% of the total, and the metals, arranged according to their concentrations, followed the order of Fe > Ca > Al > Mg > Mn > Pb > Cu > Ni > Cr > As > Cd. The proportion of heavy metals in PM-10 remained stable over the years. In terms of seasons, the concentrations were the highest in spring, followed by winter, autumn, and then summer. The site-specific analysis showed that the total heavy-metal concentrations were the highest in Daebul, followed by Myodo-dong, Jung-dong, Yulchon-myeon, Sindae-ri, Yeocheon-dong, and then Ssangbong-dong. Factor analysis revealed three major sources: (1) soil-origin components (Fe, Ca, Mg, and Al), (2) vehicle emissions and coal combustion (Pb, Cd, and As), and (3) industrial pollution (Cr, Cu, Mn, and Ni). Furthermore, the Fe concentrations varied by site, with Daebul and Myodo-dong strongly influenced by industrial activities, while other sites were more affected by natural factors.
In South Korea, various local governments, including Seoul, Incheon, Gyeonggi, Gyeong sang, and Joella, are proactively assessing the extent of microplastic pollution in freshwater. In contrast, microplastic pollution research in Gangwon Special Self-Governing Province is lacking. To address this, in this study, sampling was undertaken in Hongcheon and Jeongseon, along with in highland agricultural watersheds, which are major sources of non-point source pollution. Microplastic analysis of the samples was conducted using a micro-Raman spectrometer. During non-rainy periods, microplastic concentrations in river samples were approximately 13-438 particles/L and 40-452 particles/L in Hongcheon and Jeongseon, respectively. During rainy periods, the concentrations were approximately 67-313 particles/L and 98–103 particles/L in Hongcheon and Jeongseon, respectively. The types of microplastics detected in the samples included polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate, with polyethylene and polypropylene being the most prevalent. From this study, a database on microplastic pollution levels and types present in the highland farming watersheds of Gangwon was established.
This study conducted site assessments of 66 test institutions in the waste sector, 73 test institutions in the soil sector, and 104 institutions in the indoor air quality sector, key deficiencies. In the waste sector, common deficiencies included the inadequate sample collection, insufficient familiarity with the testing methods, and poor sample homogenization. In the soil sector, the contamination of the background sample and quality control when replacing the test personnel were identified as common deficiencies. In the indoor air quality sector, common deficiencies include inadequate sample collection records and poor performance checks of the DNPH cartridge. The results highlight the critical need for improved record management across sample collection and analysis.
The SIFT-MS measurement system is a new useful analytical tool for odor analysis due to its high sensitivity detection and quantification of multiple odorants simultaneously in real time. However, the Korean analytical standard technique lacks a QA/QC methodology for real-time measurement. In this study, three distinct Method Detection Limit (MDL) estimation procedures were evaluated to determine the optimal quality control strategy for the SIFT-MS real-time analytical method: (1) MDLs created with spiked samples, (2) MDLb based on method blanks, and (3) LOD provided in the instrument operating manual. The results revealed that the MDLs were the most significant of the three estimated results, followed by the MDLb and the LOD. The US EPA procedure recommends selecting the greater value, which in this study corresponds to the MDLs; however, the absence of gas-phase CRMs for 18 out of the 22 odor compounds limited the applicability of MDLs. As a result, we selected the MDLb estimation based on ambient background air as the most appropriate approach for determining the MDL in the real-time monitoring system. In 2024, monitoring data obtained using the SIFT-MS measurement system in a casting industrial complex in Gyeongsangnam-do revealed that hydrogen sulfide, toluene, acetaldehyde, and xylenes are the key management target compounds of the odor emission sources.
Aldehydes are among the major air pollutants due to their contribution to photochemical smog, health hazards, and odor. However, few studies have examined aldehyde concentration levels in flue gas, and only a limited number of substances have established emission limits. In this study, a method for the analysis of 14 aldehydes using HPLC-HRMS was optimized, and aldehyde concentrations in flue gas were measured. The optimized method for target substance qualification and quantification demonstrated linearity within a calibration range of 5-100 ng/mL, recoveries of 84-104 %, and precision ranging from 1-9 %. The method detection limit(MDL) for each compound ranged from 0.067-0.377 ng/mL, and the limit of quantification(LOQ) ranged from 0.212-1.202 ng/mL. In the flue gas samples, formaldehyde and acetaldehyde were detected in all stacks, but their concentrations remained within emission limits. However, many substances without established emission limits were also detected, with detection patterns varying by workplace. It appears necessary to characterize workplace types and implement tailored management strategies. The data collected in this study on aldehyde emissions in flue gas can support the identification of workplace-specific characteristics and the establishment of management standards.
This study aims to investigate both qualitative and quantitative methods for the simultaneous multicomponent and trace analysis of free amino acids (FAAs) in atmospheric particulate matter using LC-HRMS. The method was applied by collecting samples to assess the actual occurrence of FAAs in the atmosphere. The analytical technique utilized was LC-HRMS (Orbitrap), with a focus on the Amino Acid column, which demonstrated excellent separation performance, with peak detection beginning approximately five minutes after sample injection. A total of 15 FAA species were analyzed within a 20-minute run time. Accelerated solvent extraction (ASE) was effective, and the relatively low recovery rate was compensated for by using 15 internal standards. The matrix test confirmed that the method can be applied to actual particulate matter (PM) samples. Analysis of 13 PM samples collected over a two-month period revealed that L-valine was the most abundant FAA. FAAs in fine particulate matter accounted for approximately 6% of the total FAA, with 72% of this fraction found in ultrafine dust particles. This study advances the analytical method for trace-level detection of FAAs, facilitating their identification and quantification in atmospheric particulate matter.
This study determines the actual amount and quality of sewage generated from various types of buildings with diverse sewage inflow patterns. The findings highlight the necessity of revising the notice to account for deviations from the existing sewage calculation method. Samples were retrieved from flow equalization tanks of sewage treatment plants. The inflow biochemical oxygen demand (BOD) concentration of general restaurants ranged from 153.8 to 2,700.0 mg/L, i.e., 46.6 to 818.2% of the standard value of 330 mg/L issued by the Ministry of Environment. For cafeterias, BOD concentration ranged from 85.5 to 690.0 mg/L, and for the rice cake manufacturing factory, it ranged from 360.0 to 855.0 mg/L—exceeding the issued standard value of 100 mg/L in both cases. The daily sewage amount generated per unit floor area in five restaurants ranged from 12.9 to 97.0 L/m2. These values were below the existing standard of 60 L/m2 except for that of restaurant A (i.e., 97.0 L/m2). The daily sewage generation for cafeterias ranged from 62.6 to 104.2 L/m2. In most cases, these values exceeded the existing standard of 35 L/m2 by a factor of > 2. For the rice cake manufacturing factory, the daily sewage generation was 19.8 L/m2, i.e., higher than the existing standard of 15 L/m2. Since the characteristics of sewage generation vary significantly depending on the building use type, it is necessary to further subdivide and manage the amounts of sewage generation under the existing law.
In this study, an eductor was designed and integrated into the Induced Gas Flotation (IGF) process to enhance oil removal from produced water. The eductor was specifically engineered to generate microbubbles, thereby improving gas-liquid interactions and promoting efficient oil separation. A series of experiments was conducted to investigate the effects of key operating parameters - oil concentration, salinity, recycle ratio, and water temperature - on oil removal efficiency. The results demonstrated that the highest removal efficiencies, 99.4% and 97.5%, were achieved at a salinity of 10,000 ppm and a recycle ratio of 80%, at water temperatures of 40℃ and 50℃, respectively. Among the parameters studied, salinity and water temperature were identified as the dominant factors influencing the initial stabilization and overall performance of the flotation process. These findings indicate that optimizing microbubble generation and controlling specific operating conditions can substantially enhance the efficiency of IGF systems.
This study used inductively coupled plasma optical emission spectrometry to evaluate the uncertainty associated with measuring the cadmium content in waste sample. In this study, the uncertainty factors were divided into acid digestion, standard solutions for calibration curve, calibration curve, and repeated measurement. The cadmium content was determined to be 109.12 ± 3.60 mg/kg. In addition, it had a significant impact on the uncertainty in the calibration curve and the standard solutions for constructing the calibration curve. The uncertainty in the calibration curve can be reduced by increasing the concentration of the standard solution, as proposed in previous studies. In addition, to reduce the uncertainty that arises from preparing standard solutions, an alternative would be to pipette the liquid as the weight corresponding to the target volume instead of the volume itself.
The ecotoxicity value of unknown harmful substances contained in effluent was calculated by determining the health status of Daphnia magna (water fleas) through a standard reference toxicity test (ES 04705.1b). For this test, the Daphnia magna was cultured with static non-renewal culture and the Daphnia magna neonate was separated, which was time-consuming. This problem was solved by developing a continuous water flea culture apparatus and a continuous culture method. Standard reference toxicity tests were performed to confirm the health status of static non-renewal cultured Daphnia magna and continuous cultured Daphnia magna. We found that the average test value (EC50) for neonate separated from static non-renewal cultured Daphnia magna was 1.020 mg/L. Additionally, the average test value (EC50) for neonate separated in natural flow from continuous cultured Daphnia magna was 0.992 mg/L. It was confirmed that the EC50 values for potassium dichromate were in the satisfactory range of 0.9 to 2.1 mg/L, so it was valid for ES 04705.1b and ISO 6341:2012. In conclusion, there is a high chance for saving time and effort for toxicity evaluation when the continuous culture apparatus is used.
This study aims to assess the water quality of 343 groundwater samples used for drinking in emergency situations in the Busan region, focusing on physicochemical and biological contaminants, as well as radon and uranium. The proportion of groundwater facilities exceeding the Korean drinking water quality standard was 18.4% (63 sites). Microbial indicators such as total coliforms, total colony counts, and fecal coliforms, were detected at a high rate of 90%. To reduce microbial contamination, the management of the groundwater facilities should focus on disinfection and cleaning. The concentrations of radon and uranium were found to range from ND to 138 Bq/L and ND to 22 μg/L, respectively, with little correlation between these natural radioactive materials (r = 0.105). Hardness showed the highest positive correlation with chloride and sulfate ions, and this is considered to be an effect of topography rather than external water pollution. Monitoring data on hardness, chloride ion, nitrate as nitrogen, radon and uranium from groundwater were visualized on the Busan map to illustrate the distribution of major contaminants. These findings provide valuable information for developing groundwater monitoring policies.
