Association between dementia diagnosis at dialysis initiation and mortality in older patients with end-stage kidney disease in South Korea.

Background: The prevalence of dementia is 2- to 7-fold higher among patients with end-stage kidney disease (ESKD) than among the general population; however, its clinical implications in this population remain unclear. Therefore, this study aimed to determine whether comorbid dementia increases mortality among older patients with ESKD undergoing newly initiated hemodialysis. Methods: We analyzed data from the Korean Society of Geriatric Nephrology retrospective cohort, which included 2,736 older ESKD patients (≥70 years old) who started hemodialysis between 2010 and 2017. Kaplan-Meier survival and Cox regression analyses were used to examine all-cause mortality between the patients with and without dementia in this cohort. Results: Of the 2,406 included patients, 8.3% had dementia at the initiation of dialysis; these patients were older (79.6 ± 6.0 years) than patients without dementia (77.7 ± 5.5 years) and included more women (male:female, 89:111). Pre-ESKD diagnosis of dementia was associated with an increased risk of overall mortality (hazard ratio, 1.503; p < 0.001), and this association remained consistent after multivariate adjustment (hazard ratio, 1.268; p = 0.009). In subgroup analysis, prevalent dementia was associated with mortality following dialysis initiation in female patients, those aged <85 years, those with no history of cerebrovascular accidents or severe behavioral disorders, those not residing in nursing facilities, and those with no or short-term hospitalization. Conclusion: A pre-ESKD diagnosis of dementia is associated with mortality following dialysis initiation in older Korean population. In older patients with ESKD, cognitive assessment at dialysis initiation is necessary.

Role of the CCL20/CCR6 axis in tubular epithelial cell injury: Kidney-specific translational insights from acute kidney injury to chronic kidney disease.

This study investigated the role of the axis involving chemokine receptor 6 (CCR6) and its ligand chemokine (C-C motif) ligand 20 (CCL20) in acute kidney disease (AKD) using an ischemia-reperfusion injury (IRI) model. The model was established by clamping the unilateral renal artery pedicle of C57BL/6 mice for 30 min, followed by evaluation of CCL20/CCR6 expression at 4 weeks post-IRI. In vitro studies were conducted to examine the effects of hypoxia and H2 O2 -induced oxidative stress on CCL20/CCR6 expression in kidney tissues of patients with AKD and chronic kidney disease (CKD). Tubular epithelial cell apoptosis was more severe in C57BL/6 mice than in CCL20 antibody-treated mice, and CCR6, NGAL mRNA, and IL-8 levels were higher under hypoxic conditions. CCL20 blockade ameliorated apoptotic damage in a dose-dependent manner under hypoxia and reactive oxygen species injury. CCR6 expression in IRI mice indicated that the disease severity was similar to that in patients with the AKD phenotype. Morphometry of CCL20/CCR6 expression revealed a higher likelihood of CCR6+ cell presence in CKD stage 3 patients than in stage 1-2 patients. Kidney tissues of patients with CKD frequently contained CCL20+ cells, which were positively correlated with interstitial inflammation. CCL20/CCR6 levels were increased in fibrotic kidneys at 4 and 8 weeks after 5/6 nephrectomy. These findings suggest that modulating the CCL20/CCR6 pathway is a potential therapeutic strategy for managing the progression of AKD to CKD.

Pneumatic driven pulsatile ECMO in vitro evaluation with oxygen tanks.

Extracorporeal membrane oxygenation device is a procedure in which mechanical systems circulate blood and supply oxygen to patients with impaired cardiopulmonary function. Current venoarterial systems are associated with low patient survival rates and new treatments are needed to avoid left ventricular dilation, which is a major cause of death. In this study, a new mobile pulsatile ECMO with a pump structure that supplies pulsatile flow by using an oxygen tank as a power source is proposed. In vitro experiments conducted under mock circulation system as like patient conditions demonstrated that 2.8 L oxygen can sustain the outflow of 1 L/min of pulsatile blood flow for 53 min, while a 4.6 L tank was able to sustain the same flow for 85 min. The energy equivalent pressure evaluation index of the pulsatile blood pump shows that the mobile pulsatile ECMO could supply sufficient pulsatile blood flow compared to the existing pulsatile ECMO. Through in vitro experiments performed under mock circulation conditions, this new system was proven to supply sufficient oxygen and pulsatile blood flow using the pressure of an oxygen tank even while transporting a patient.

Association between food insecurity and risk of chronic diseases affecting the kidney in older Korean patients.

AIMS: This study aimed to examine the association between food insecurity and the prevalence of chronic diseases among older adults in South Korea and to compare the findings with data from the United States (US). MATERIALS AND METHODS: We analyzed data from the Korea National Health and Nutrition Examination Survey (KNHANES) V (2010 - 2012) and VI (2013 - 2015) and 4 years (2012 - 2015) of food security questionnaire data. The data of 46,189 National Health and Nutrition Examination Survey participants (1999 - 2016) were subjected to propensity score-matched (PSM) analysis. RESULTS: We included 7,914 individuals from the KNHANES. In the older group (age > 65 years), no differences were observed in the prevalence of hypertension, diabetes, chronic kidney disease (CKD), and metabolic syndrome across the income groups. Income, education, and food security had no impact on hypertension, diabetes, and CKD prevalence in the multivariate logistic analysis after PSM. CKD was not associated with food insecurity (odds ratio (OR), 1.26; 95% confidence interval (CI), 0.94 - 1.26) in the final model using the KNHANES data; however, the U.S. NHANES data showed that an increased risk of hypertension was associated with food insecurity (OR, 1.27; 95% CI, 1.04 - 1.55). CONCLUSION: As per the U.S. NHANES data, food insecurity was associated with a high prevalence of hypertension, while as per the South Korean KNHANES data, food insecurity was not found to be associated with CKD, indicating divergent relationships between food insecurity and chronic diseases in the two countries. Further research is needed to explore these differences.

IDH-wildtype secondary glioblastoma arising in IDH-mutant diffuse astrocytoma: a case report.

Primary glioblastoma develops de novo without clinical or histological evidence of a low-grade precursor lesion, whereas secondary glioblastoma develops from a low-grade glioma. The present report describes an extraordinary case of IDH-wildtype secondary glioblastoma arising in IDH-mutant diffuse astrocytoma. A 31-year-old female had a surgical history of IDH-mutant diffuse astrocytoma on the left frontal lobe six years before. Magnetic resonance imaging revealed new infiltrative lesions in the left frontal lobe adjacent to the previous lesion. The patient underwent tumourectomy, and the new infiltrative lesion was diagnosed as glioblastoma. Interestingly, the IDH-1 (p.Arg132His) mutation was found in diffuse astrocytoma but not in glioblastoma based on next generation sequencing. ATRX (p.Gln1670Ter) and TP53 (p.His193Arg) mutations were found in both lesions. Additionally, the PTEN (p.His296Pro) mutation was identified only in glioblastoma. A well-accepted hypothesis is that the IDH mutation initiates in glial progenitor cells and causes secondary glioblastoma harboring the IDH mutation to develop from low grade glioma with IDH mutation. However, this case showed that the other genetic mutations can be initiated before the IDH mutation in glioma oncogenesis. Contrary to the previous hypothesis, this is the first case of IDH-wildtype secondary glioblastoma arising in IDH-mutant diffuse astrocytoma.

Comparative Study of Sampling and Measurement Methods for the Development of CH4 Emission Factors at MSW Incinerators.

Lung samplers (periodic sampling) have generally been used to develop CH4 emission factors in waste incineration facilities. Since this method must be calculated using only the value at a specific point in time, it may not reflect the emission characteristics depending on the circumstances of the facility. In order to supplement this method, a method of continuously collecting samples for a long period of time or continuously measuring may be used. In this study, the CH4 emission factor development and titration methodology were reviewed using both the existing methods and the newly proposed continuous sampling and continuous measurement methods. As a result of the analysis, the average emission factor by periodic sampling was 0.201 gCH4/ton-waste, the average emission factor by continuous capture was 0.199 gCH4/ton-waste, and the average emission factor by continuous measurement was 0.176 gCH4/ton-waste. There was a difference of 0.025 gCH4/ton-waste in the emission factor values by periodic sampling and continuous measurement, and the emission factor values for periodic sampling and continuous sampling were similar. There was no statistically significant difference, confirming that all three methods could be used. However, the existing method, periodic sampling, cannot reflect the characteristics of the night, and, in the case of continuous measurement, expensive equipment and maintenance are difficult. Therefore, it is judged that the method using continuous sampling is a good method that can combine the two advantages.

Ammonia Emissions from NPK Fertilizer Production Plants: Emission Characteristics and Emission Factor Estimation.

Fertilizers are made from manure, but they are also produced through chemical processes. Fertilizer is an ammonia emission source; it releases ammonia when used. Ammonia is also emitted during the production process. Although many studies related to fertilizer application have been conducted, there are few research cases related to the production process and related emissions are not calculated. In this study, the ammonia emissions from NPK (nitrogen phosphorus Potassium oxide) fertilizer production facilities were checked through actual measurement and related characteristics were analyzed. In addition, emission factors were developed, and the necessity of developing emission factors was also confirmed. As a result of the development of the emission factor, it was found to be 0.001 kgNH3/ton, which is like the range of emission factors in related fields. The NPK ammonia emission factor of this study was found to be higher than the minimum emission factor currently applied in South Korea, and it was judged to be a level that can be used as an emission factor.

Development of Ammonia Emission Factor for Industrial Waste Incineration Facilities Considering Incinerator Type.

In this study, the emission factor and concentration of ammonia from industrial waste incineration facilities were analyzed through actual measurements. The ammonia emission factor was calculated and the difference in ammonia emission factor for each type of incineration was confirmed through the Mann−Whitney U test. As a result of analyzing 279 samples, the NH3 emission factor of the SNCR facility of stoker types was 0.012 kgNH3/ton, and the NH3 emission factor of the SNCR facility of the rotary kiln methods was 0.014 kgNH3/ton. Additionally, the NH3 emission factor of this study was higher than the NH3 emission factor (0.003 kgNH3/ton) suggested by Kang's study (0.009 kgNH3/ton) and EMEP/EEA (2006). There is a need to develop an NH3 emission factor that takes into account the characteristics of Korea, since it is largely different from the NH3 emission factor of EMEP/EEA. As a result of statistical analysis of the stoker type and the rotary kiln method, the null hypothesis that there is no difference between each type was adopted (p-value > 0.05), indicating that there was no statistical difference in the ammonia emission factors of the stoker type and the rotary kiln type.

Study on Enhanced Methods for Calculating NH3 Emissions from Fertilizer Application in Agriculture Sector.

Ammonia is a representative PM-2.5 secondary product, and the need for management is emerging as health and living damage caused by fine particulate matter worsens. The main source of ammonia is the agricultural sector, and in Korea, 79% of the total ammonia emissions are emitted from the agricultural sector. Among them, there is high uncertainty about how to calculate emissions from ammonia discharged from fertilizer use, and inventory in the U.S. and Europe is borrowed, so inventory needs to be improved according to the situation in Korea. In this study, the ammonia inventory in the agricultural sector in Korea and abroad was examined, and additional activity data that can be used were reviewed. In addition, in order to improve the emission calculation method, the emission was calculated in three ways by different factors. As a result, it was confirmed that the amount of discharge varies depending on the type of soil use or whether cultivated crops are considered, and the possibility of excessive fertilizer top-dress by farmers was confirmed. In order to calculate the emission at a more detailed level based on this study, basic data such as fertilizer input method and regional distribution of crops should be systematically collected, and related follow-up studies should be conducted.

Mixed Use of Bio-Oil in Oil Power Plants: Should It Be Considered When Developing NH3 Emission Factors?

In order to cope with recent climate change, Korea is reducing the use of heavy oil in petroleum-fired power plants and mixing bio-oils. Accordingly, this must be taken into account when calculating the emissions of air pollutants. However, in the case of Korea, when calculating NH3 emissions, the United States Environmental Protection Agency (EPA) emission factor is applied as it is to calculate emissions, and for petroleum power plants, the heavy oil emission factor proposed by EPA is used as it is to calculate emissions. In petroleum power plants, bio-oil is not mixed in a certain amount and used at a different ratio depending on the situation of the power plant. Therefore, in this study, the NH3 emission factor according to the mixing ratio of bio-heavy oil is calculated and the mixing ratio is calculated. As a result of the analysis, the emission factor according to bio-oil and the mixed ratio was found to be in the range of 0.010~0.033 kg NH3/kL, and it was lower than the heavy oil emission factor 0.096 kg NH3/kL of EPA currently used in Korea. This is because the amount of NH3 through the slip is also small since the use of NH3 for reduction is also low because the NOx emission from the use of bio-oil is low. Considering all of these points, we have statistically analyzed whether emission factors should be developed and applied. As a result of the confirmation, the difference according to the mixed consumption rate was not large.

Estimating the Characteristics and Emission Factor of Ammonia from Sewage Sludge Incinerator.

In the case of sewage sludge, as direct landfilling was recently prohibited, it is treated through incineration. Among the air pollutants discharged through the incineration of sewage sludge, NOx and SOx are considered secondary substances of PM2.5 and are being managed accordingly. However, NH3, another of the secondary substances of PM2.5, is not well managed, and the amount of NH3 discharged from sewage sludge incineration facilities has not been calculated. Therefore, in this study, we sought to determine whether NH3 is discharged in the exhaust gas of a sewage sludge incineration facility, and, when discharged, the NH3 emission factor was calculated, and the necessity of the development of the emission factor was reviewed. As a result of the study, it was confirmed that the amount of NH3 discharged from the sewage sludge incineration facility was 0.04 to 4.47 ppm, and the emission factor was calculated as 0.002 kg NH3/ton. The NH3 emission factor was compared with the NH3 emission factor of municipal solid waste proposed by EMEP/EEA (European Monitoring and Evaluation Programme/European Environment Agency) because the NH3 emission factor of the sewage sludge incineration facility had not been previously determined. As a result of the comparison, the NH3 emission factor of EMEP/EEA was similar to that of municipal solid waste, confirming the necessity of developing the NH3 emission factor of the sewage sludge incineration facility. In addition, the evaluation of the uncertainty of the additionally calculated NH3 emission factor was conducted quantitatively and the uncertainty range was presented for reference. In the future, it is necessary to improve the reliability of the NH3 emission factor of sewage sludge incineration facilities by performing additional analysis with statistical representation. In addition, the development of NH3 emission factors for industrial waste incineration facilities should be undertaken.

High prevalence of physical inactivity after heart valve surgery and its association with long-term mortality: A nationwide cohort study.

AIMS: Physical activity (PA) and systematic efforts, such as cardiac rehabilitation, are recommended by several national guidelines for those who have received heart valve surgery. However, only a few studies have demonstrated real-world situations, such as changes in the PA level after heart valve surgery, and their effects on long-term outcomes. We designed this study to investigate the changes in PA after heart valve surgery and their associations with mortality using nationwide representative data. METHODS: This study was performed using the Korean National Health Insurance Service database. We included patients who received heart valve surgery from 2009 to 2015 and underwent regular health checkups before and after surgery. Subjects were grouped according to their PA level before and after the surgery. Information on all-cause mortality was obtained until 31 December 2016, with a maximum follow-up period of 5 years. RESULTS: Of the 6587 subjects, 3258 (49.5%) were physically inactive after surgery. Among patients who were physically active (n = 3070), 1196 (39.0%) became inactive after surgery. The postoperative 'inactive' group showed higher mortality than the 'active' group (hazard ratio (HR): 1.41, 95% confidence interval (CI): 1.08-1.83). The 'inactive/inactive' group showed the highest risk of mortality (HR: 1.69, 95% CI: 1.19-2.40) compared with the 'active/active' group. CONCLUSIONS: Insufficient PA level after heart valve surgery is associated with higher risk of mortality. However, maintaining sufficient PA after heart valve surgery may be challenging for many patients. Therefore, systematic efforts, such as cardiac rehabilitation, should be considered in those who received heart valve surgery.

Physical activity after ischemic stroke and its association with adverse outcomes: A nationwide population-based cohort study.

BACKGROUND: Sufficient physical activity (PA) is highly recommended to improve the prognosis after stroke. However, there have been only a few studies evaluating the changes in PA level after stroke. AIMS: We aimed to identify the changes in PA level between before and after stroke, and to determine the association between PA and adverse outcomes. METHODS: This observational, retrospective cohort study was performed using  the Nationwide Health Insurance Service (NHIS) database in South Korea. Subjects between the ages of 20 to 80 years, who had a first-ever ischemic stroke from 2010 to 2013, were included. Subjects were divided into either the "sufficient" or "insufficient" subgroups, depending on the result of the self-reported PA questionnaire. Adverse outcomes, including all-cause mortality, stroke recurrence, and myocardial infarction (MI), were collected from a post-stroke health checkup to 2017. RESULTS: Of the 34,243 subjects with ischemic stroke, only 21.24% had sufficient PA level after stroke. Among those with insufficient PA level, only 17.34% improved their PA level after stroke. Subjects with sufficient PA level after stroke, regardless of their PA level prior to stroke, showed a lower risk of composite adverse outcomes (adjusted Hazard Ratio [HR], 95% CI: 0.85, 0.80-0.90). Subjects who went from insufficient to sufficient PA level (HR 0.87, 95% CI: 0.81-0.93) showed a significantly lower risk of composite adverse outcomes. CONCLUSIONS: Achieving a sufficient PA level after ischemic stroke appears to significantly reduce major adverse events. Further effort is needed to promote the PA level after ischemic stroke.

Optimization of a chest computed tomography protocol for detecting pure ground glass opacity nodules: A feasibility study with a computer-assisted detection system and a lung cancer screening phantom.

OBJECTIVE: This study aimed to optimize computed tomography (CT) parameters for detecting ground glass opacity nodules (GGNs) using a computer-assisted detection (CAD) system and a lung cancer screening phantom. METHODS: A lung cancer screening phantom containing 15 artificial GGNs (-630 Hounsfield unit [HU], 2-10 mm) in the left lung was examined with a CT scanner. Three tube voltages of 80, 100, and 120 kVp were used in combination with five tube currents of 25, 50, 100, 200, and 400 mA; additionally, three slice thicknesses of 0.625, 1.25, and 2.5 mm and four reconstruction algorithms of adaptive statistical iterative reconstruction (ASIR-V) of 30, 60, and 90% were used. For each protocol, accuracy of the CAD system was evaluated for nine target GGNs of 6, 8, or 10 mm in size. The cut-off size was set to 5 mm to minimize false positives. RESULTS: Among the 180 combinations of tube voltage, tube current, slice thickness, and reconstruction algorithms, combination of 80 kVp, 200 mA, and 1.25-mm slice thickness with an ASIR-V of 90% had the best performance in the detection of GGNs with six true positives and no false positives. Other combinations had fewer than five true positives. In particular, any combinations with a 0.625-mm slice thickness had 0 true positive and at least one false positive result. CONCLUSION: Low-voltage chest CT with a thin slice thickness and a high iterative reconstruction algorithm improve the detection rate of GGNs with a CAD system in a phantom model, and may have potential in lung cancer screening.

Ammonia Emission Sources Characteristics and Emission Factor Uncertainty at Liquefied Natural Gas Power Plants.

This study developed the NH3 emission factor for Liquefied Natural Gas (LNG) power facilities in Korea by analyzing the emission characteristics from two LNG power plants using methods such as uncertainty analysis. Also, comparing the differences in NH3 emission levels between the developed emission factors, which reflect the characteristics in Korea, and the U.S. Environmental Protection Agency (EPA) values currently applied in Korea. The estimation showed that the NH3 emission factor for the LNG power plants was 0.0054 ton NH3/106Nm3, which is approximately nine times less than the EPA NH3 emission factor of 0.051 ton NH3/106Nm3 for LNG fuels of the industrial energy combustion sector currently applied in national statistics in Korea. The Selective Catalytic Reduction (SCR) emission factor for LNG power plants was 0.0010 ton NH3/106Nm3, which is considerably lower than the EPA NH3 emission factor of 0.146 ton NH3/106Nm3 currently applied in national statistics in Korea for the LNG fuels of the industrial process sector. This indicated the need for developing an emission factor that incorporates the unique characteristics in Korea. The uncertainty range of the LNG stack NH3 emission factor developed in this study was ±10.91% at a 95% confidence level, while that of the SCR NH3 emission factor was -10% to +20% at a 95% confidence level, indicating a slightly higher uncertainty range than the LNG stack. At present, quantitative analysis of air pollutants is difficult because numerical values of the uncertainty are not available. However, quantitative analysis might be possible using the methods applied in this study to estimate uncertainty.

Coronavirus Disease 19 (COVID-19) complicated with pneumonia in a patient with rheumatoid arthritis receiving conventional disease-modifying antirheumatic drugs.

In December 2019, numerous coronavirus disease 2019 (COVID-19) cases were reported in Wuhan, China, which has since spread throughout the world. However, its impact on rheumatoid arthritis (RA) patients is unknown. Herein, we report a case of COVID-19 pneumonia in a 61-year-old female RA patient who was receiving conventional disease-modifying antirheumatic drugs (cDMARDs). The patient presented with a 4-day history of myalgia and febrile sensation. COVID-19 was confirmed by real-time polymerase chain reaction (PCR). Chest X-ray showed increased opacity on the right lower lung area, and C-reactive protein level was slightly elevated. The patient was treated with antiviral agents (lopinavir/ritonavir), and treatment with cDMARDs was discontinued except hydroxychloroquine. Her symptoms and laboratory results gradually improved. Three weeks later, real-time PCR for COVID-19 showed negative conversion, and the patient was discharged without any complications.

Utility of CPR Machine Power and Change in Right Atrial Pressure for Estimating CPR Quality.

When a cardiac arrest occurs, it is necessary to perform cardiopulmonary resuscitation (CPR) as soon as possible. This requires maintaining the pressure depth at 5 cm at a rate of 100 cpm. For CPR machines, which are frequently used in ambulances, the return of spontaneous circulation (ROSC) is not superior to that of manual CPR, although CPR machines can maintain the compression rate and reciprocal distance of the compression plate more accurately. When the thoracic cavity is deformed due to repeated chest compressions, CPR machines must be adjusted. It is necessary to develop a method for measuring whether adequate CPR is achieved using CPR machines. CPR was performed on two pigs with a CPR machine, commencing 1 minute after the heart was stopped. Four CPR modes were used, with compression rates of 60 or 100 cpm and compression depths of 3 or 5 cm. The CPR machine was equipped with a load cell for measuring compression force, and a potentiometer for measuring compression depth. The measurement results obtained from the sensor were used to calculate the frequency components. The compression force and depth data were used to calculate the mechanical power of the CPR machine and mechanical impedance of the thoracic cavity. Changes in end-tidal carbon dioxide (ETCO2), coronary perfusion pressure (CPP), carotid blood flow (CBF), and right atrial pressure (RAP) were measured during performance of CPR; change in RAP refers to variation therein with chest compressions. Continuous CPR in both animals resulted in deformation of the chest cavity and a steady decline in impedance. The correlation between CPR power and change in RAP was 0.78, and that between compression force and CBF was 0.64. Impedance was not correlated with blood pressure or CBF. When the condition of the animal deteriorated due to cardiac arrest, the CPP decreased and ETCO2 increased. The CPR power and RAP varied according to the CPR mode rather than the condition of the animal. Measuring the CPR machine power does not require a separate procedure, such as catheter intubation, so should be suitable as an index of the quality of CPR in emergency situations.

Estimation of optimal biomass fraction measuring cycle formunicipal solid waste incineration facilities in Korea.

This study estimates the optimum sampling cycle using a statistical method for biomass fraction. More than ten samples were collected from each of the three municipal solid waste (MSW) facilities between June 2013 and March 2015 and the biomass fraction was analyzed. The analysis data were grouped into monthly, quarterly, semi-annual, and annual intervals and the optimum sampling cycle for the detection of the biomass fraction was estimated. Biomass fraction data did not show a normal distribution. Therefore, the non-parametric Kruskal-Wallis test was applied to compare the average values for each sample group. The Kruskal-Wallis test results showed that the average monthly, quarterly, semi-annual, and annual values for all three MSW incineration facilities were equal. Therefore, the biomass fraction at the MSW incineration facilities should be calculated on a yearly cycle which is the longest period of the temporal cycles tested.

The comparison of fossil carbon fraction and greenhouse gas emissions through an analysis of exhaust gases from urban solid waste incineration facilities.

UNLABELLED: In this study, in order to understand accurate calculation of greenhouse gas emissions of urban solid waste incineration facilities, which are major waste incineration facilities, and problems likely to occur at this time, emissions were calculated by classifying calculation methods into 3 types. For the comparison of calculation methods, the waste characteristics ratio, dry substance content by waste characteristics, carbon content in dry substance, and (12)C content were analyzed; and in particular, CO2 concentration in incineration gases and (12)C content were analyzed together. In this study, 3 types of calculation methods were made through the assay value, and by using each calculation method, emissions of urban solid waste incineration facilities were calculated then compared. As a result of comparison, with Calculation Method A, which used the default value as presented in the IPCC guidelines, greenhouse gas emissions were calculated for the urban solid waste incineration facilities A and B at 244.43 ton CO2/day and 322.09 ton CO2/day, respectively. Hence, it showed a lot of difference from Calculation Methods B and C, which used the assay value of this study. It is determined that this was because the default value as presented in IPCC, as the world average value, could not reflect the characteristics of urban solid waste incineration facilities. Calculation Method B indicated 163.31 ton CO2/day and 230.34 ton CO2/day respectively for the urban solid waste incineration facilities A and B; also, Calculation Method C indicated 151.79 ton CO2/day and 218.99 ton CO2/day, respectively. IMPLICATIONS: This study intends to compare greenhouse gas emissions calculated using (12)C content default value provided by the IPCC (Intergovernmental Panel on Climate Change) with greenhouse gas emissions calculated using (12)C content and waste assay value that can reflect the characteristics of the target urban solid waste incineration facilities. Also, the concentration and (12)C content were calculated by directly collecting incineration gases of the target urban solid waste incineration facilities, and greenhouse gas emissions of the target urban solid waste incineration facilities through this survey were compared with greenhouse gas emissions, which used the previously calculated assay value of solid waste.

The study on biomass fraction estimate methodology of municipal solid waste incinerator in Korea.

UNLABELLED: In Korea, the amount of greenhouse gases released due to waste materials was 14,800,000 t CO2eq in 2012, which increased from 5,000,000 t CO2eq in 2010. This included the amount released due to incineration, which has gradually increased since 2010. Incineration was found to be the biggest contributor to greenhouse gases, with 7,400,000 t CO2eq released in 2012. Therefore, with regards to the trading of greenhouse gases emissions initiated in 2015 and the writing of the national inventory report, it is important to increase the reliability of the measurements related to the incineration of waste materials. This research explored methods for estimating the biomass fraction at Korean MSW incinerator facilities and compared the biomass fractions obtained with the different biomass fraction estimation methods. The biomass fraction was estimated by the method using default values of fossil carbon fraction suggested by IPCC, the method using the solid waste composition, and the method using incinerator flue gas. The highest biomass fractions in Korean municipal solid waste incinerator facilities were estimated by the IPCC Default method, followed by the MSW analysis method and the Flue gas analysis method. Therefore, the difference in the biomass fraction estimate was the greatest between the IPCC Default and the Flue gas analysis methods. The difference between the MSW analysis and the flue gas analysis methods was smaller than the difference with IPCC Default method. This suggested that the use of the IPCC default method cannot reflect the characteristics of Korean waste incinerator facilities and Korean MSW. IMPLICATIONS: Incineration is one of most effective methods for disposal of municipal solid waste (MSW). This paper investigates the applicability of using biomass content to estimate the amount of CO2 released, and compares the biomass contents determined by different methods in order to establish a method for estimating biomass in the MSW incinerator facilities of Korea. After analyzing the biomass contents of the collected solid waste samples and the flue gas samples, the results were compared with the Intergovernmental Panel on Climate Change (IPCC) method, and it seems that to calculate the biomass fraction it is better to use the flue gas analysis method than the IPCC method. It is valuable to design and operate a real new incineration power plant, especially for the estimation of greenhouse gas emissions.