CalTOX 모델을 이용한 대산 석유화학단지의 활동단계에 따른 벤젠 흡입 노출평가

이진헌(Jinheon Lee),이민우(Minwoo Lee),박창용(Changyong Park),박상현(Sanghyun Park),송영호(Youngho Song),김옥(Ok Kim),신지훈(Jihun Shin) 한국환경보건학회 2022 한국환경보건학회지 Vol.48 No.3

Background: Chemical emissions in the environment have rapidly increased with the accelerated industrialization taking place in recent decades. Residents of industrial complexes are concerned about the health risks posed by chemical exposure. Objectives: This study was performed to suggest modeling methods that take into account multimedia and multi-pathways in human exposure and risk assessment. Methods: The concentration of benzene emitted at industrial complexes in Daesan, South Korea and the exposure of local residents was estimated using the Caltox model. The amount of human exposure based on inhalation rate was stochastically predicted for various activity stages such as resting, normal walking, and fast walking. Results: The coefficient of determination (R2) for the CalTOX model efficiency was 0.9676 and the root-meansquare error (RMSE) was 0.0035, indicating good agreement between predictions and measurements. However, the efficiency index (EI) appeared to be a negative value at -1094.4997. This can be explained as the atmospheric concentration being calculated only from the emissions from industrial facilities in the study area. In the human exposure assessment, the higher the inhalation rate percentile value, the higher the inhalation rate and lifetime average daily dose (LADD) at each activity step. Conclusions: Prediction using the Caltox model might be appropriate for comparing with actual measurements. The LADD of females was higher ratio with an increase in inhalation rate than those of males. This finding would imply that females may be more susceptible to benzene as their inhalation rate increases.

한국의 의료폐기물 발생 및 처리의 공간적 분포에 관한 연구

오세은,이진헌,안호기,김기연,박석환,하권철,지경희,황성호,윤오섭,홍영습,이은일,김판기,이경무,Oh, Se-Eun,Lee, Jinheon,Ahn, Hoki,Kim, Ki-Youn,Park, Seokhwan,Ha, Kwonchul,Ji, Kyunghee,Hwang, Sungho,Yoon, Oh-Sub,Hong, Young-Seoub,Lee, Eunil,Kim, 한국환경보건학회 2015 한국환경보건학회지 Vol.41 No.6

Objectives: In Korea, the system of management of medical waste largely relies on the incineration method. Our study aimed to identify any regional imbalances between the generation and treatment of medical waste, and provide reference data for future policy in Korea. Methods: We analyzed data on the amount of medical waste from 2,000 hospitals in 2012, 2013, and 2014 obtained from the Korea Environment Corporation. In the Arc GIS program (version 10.2.3), the addresses of hospitals and incinerators were transformed into map coordinates. The amount of waste generated by each hospital and the amount incinerated were represented by density and size of a triangle symbol, respectively. Results: As of 2014, the total amount of medical waste from the top 2,000 hospitals was 136,073 tons, out of which about half (49%) was generated in the capital area. Eleven incineration companies (three in the capital area, two in the Chungcheong Provinces area, one in the Jeolla Provinces area, and five in the Gyeongsang Provinces area) treated this waste. For the years 2012, 2013, and 2014, about 60% of the medical waste generated from the hospitals in the capital area was treated within the capital area and about 40% was transported to other areas, especially the Gyeongsang Provinces area, for treatment. On the other hand, about 90% of the medical waste incinerated in the capital area originated from the capital area. Conclusion: Our results suggest a spatial imbalance between the generation and treatment of medical waste in Korea and warrants multilateral policies, including the expansion of on-site treatment, strengthening regulation of the containment of medical wastes, promoting reductions in medical waste and more.

GPT의 법적 통찰력 평가: 법률 분야에서의 GPT의 역량과 한계 탐구 - LSAT를 중점으로 -

박지원(JeeWon Park),이진헌(JinHeon Lee),최영철(JinHeon Lee) 한국정보과학회 2023 한국정보과학회 학술발표논문집 Vol.2023 No.6

CalTOX 모델을 이용한 벤젠 종합위해성평가의 불확실성 분석과 민감도 분석

김옥(Ok Kim),이민우(Minwoo Lee),송영호(Youngho Song),최진하(Jinha Choi),박상현(Sanghyun Park),박창용(Changyoung Park),이진헌(Jinheon Lee) 한국환경보건학회 2020 한국환경보건학회지 Vol.46 No.2

Objectives: The purpose of this study was to perform an aggregate human risk assessment for benzene in an industrial complex using the CalTOX model and to improve the reliability and predictability of the model by analyzing the uncertainty and sensitivity of the predicted assessment results. Methods: The CalTOXTM 4.0 beta model was used to evaluate a selected region, and @Risk 7.6 software was used to analyze uncertainty and sensitivity. Results: As a result of performing the aggregate risk assessment on the assumption that 6.45E+04 g/d of benzene would be emitted into the atmosphere over two decades, 3% of the daily source term to air remained in the selected region, and 97% (6.26E+04 g/d) moved out of the region. As for exposure by breathing, the predicted LADDinhalation was 2.14E-04 mg/kg-d, and that was assessed as making a 99.99% contribution to the LADDtotal. Regarding human Riskcancer assessment, the predicted human cancer risk was 5.19E-06 (95% CI; 4.07E-06-6.81E-06) (in the 95th percentile corresponding to the highest exposure level, a confidence interval of 90%). As a result of analyzing sensitivity, ‘source term to air’ was identified as the most influential variable, followed by ‘exposure time, active indoors (h/day)’, and ‘exposure duration (years)’. Conclusions: As for the results of the human cancer risk assessment for the selected region, the predicted human cancer risk was 5.19E-06 (95% CI; 4.07E-06-6.81E-06) (in the 95th percentile, corresponding to the highest exposure level, a confidence interval of 90%). As a result of analyzing sensitivity, ‘source term to air’ was found to be most influential.

CalTOX 모델에 의한 휘발성유기화합물의 대기 중 예측 농도와 실측 농도간의 타당성 분석에 관한 연구

김옥(Ok Kim),이민우(Minwoo Lee),박상현(Sanghyun Park),박창용(Changyoung Park),송영호(Youngho Song),김병빈(Byeongbin Kim),최진하(Jinha Choi),이진헌(Jinheon Lee) 한국환경보건학회 2020 한국환경보건학회지 Vol.46 No.5

Objectives: This study calculated local residents exposures to VOCs (Volatile Organic Compounds) released into the atmosphere using the CalTOX model and carried out uncertainty analysis and sensitivity analysis. The model validity was analyzed by comparing the predicted and the actual atmospheric concentrations. Methods: Uncertainty was parsed by conducting a Monte Carlo simulation. Sensitivity was dissected with the regression (coefficients) method. The model validity was analyzed by applying r2 (coefficient of determination), RMSE (root mean square error), and the Nash-Sutcliffe EI (efficiency index) formula. Results: Among the concentrations in the atmosphere in this study, benzene was the highest and the lifetime average daily dose of benzene and the average daily dose of xylene were high. In terms of the sensitivity analysis outcome, the source term to air, exposure time, indoors resting (ETri), exposure time, outdoors at home (ETao), yearly average wind speed (v_w), contaminated area in m2 (Area), active breathing rate (BRa), resting breathing rate (BRr), exposure time, and active indoors (ETai) were elicited as input variables having great influence upon this model. In consequence of inspecting the validity of the model, r2 appeared to be a value close to 1 and RMSE appeared to be a value close to 0, but EI indicated unacceptable model efficiency. To supplement this value, the regression formula was derived for benzene with y=0.002+15.48x, ethylbenzene with y ≡ 0.001+57.240x, styrene with y=0.000+42.249x, toluene with y=0.004+91.588x, and xylene with y=0.000+ 0.007x. Conclusions: In consequence of inspecting the validity of the model, r2 appeared to be a value close to 1 and RMSE appeared to be a value close to 0, but EI indicated unacceptable model efficiency. This will be able to be used as base data for securing the accuracy and reliability of the model.

서산지역에서 연료연소에 의해 배출된 benzo(a)pyrene의 배출량 산정

김 옥(Ok Kim),송영호(Youngho Song),이진헌(Jinheon Lee) 한국환경보건학회 2017 한국환경보건학회지 Vol.43 No.1

Objectives: This study estimated the emission quantity of benzo(a)pyrene(BaP) produced by fuel combustion in the Seosan area, and analyzed the uncertainty regarding the emissions. Methods: It was based on data from a national agency and from public institutions. Emissions were estimated by using national-level guidelines. The total estimated emissions were analyzed by performing Monte Carlo analysis. Results: The full emission quantity of BaP which was discharged by fuel combustion in the Seosan area stood at 1,194.79 g/yr. The point source emissions came to 184.16 g/yr (95% CI; 158.40-209.39). The line source emissions reached 315.33 g/yr (95% CI; 284.99-344.03). The area source emissions accounted for 695.31 g/ yr (95% CI; 605.10-793.88). Chemical and compound manufacturing was the highest with 639.13 g/yr (95% CI; 542.95-728.24) in terms of emissions and oil refinery emissions were high with 153.10 g/yr (95% CI; 129.19~177.46). It was found in the Seosan area that the major source of BaP is the manufacturing of chemicals and chemical products. Conclusion: The emission quantity of BaP which was discharged by the fuel combustion in Seosan area reached 1,194.79 g/yr. Research needs to be continued for the definite estimation of emission of BaP henceforth.

화력발전소의 혼합연료 사용에 따른 중금속 배출량 변화 연구

송영호(Youngho Song),김 옥(Ok Kim),박상현(Sanghyun Park),이진헌(Jinheon Lee) 한국환경보건학회 2018 한국환경보건학회지 Vol.44 No.1

Objectives: The aim of this research is to explore the total heavy metals from a coal-fired power plant burning bituminous coal with wood pellets due to the implementation of the Renewable Portfolio Standard policy (RPS, 10% of electricity from renewable energy resources by 2023). Methods: The research was carried out by collecting archival data and using the USEPA’s AP-42 & EMEP/EEA compilation of emission factors for use in calculating emissions. The Monte Carlo method was also applied for carrying out the calculations of measurement uncertainty. Results: In this paper, the results are listed as follows. Sb was measured at 110 kg (2015) and calculated as 165 kg (2019) and 201 kg (2023). Cr was measured at 1,597 kg (2015) and calculated as 1,687 kg (2019) and 1,728 kg (2023). Cu was measured at 2,888 kg (2015) and calculated as 3,133 kg (2019) and 3,264 kg (2023). Pb was measured at 2,580 kg (2015) and calculated as 2,831 kg (2019) and 2,969 kg (2023). Mn was measured at 3,011 kg (2015) and calculated as 15,034 kg (2019) and 23,014 kg (2023). Hg was measured at 510 kg (2015) and calculated as 513 kg (2019) and 537 kg (2023). Ni was measured at 1,720 kg (2015) and calculated as 1,895 kg (2019) and 1,991 kg (2023). Zn was measured at 7,054 kg (2015) and calculated as 9,938 kg (2019) and 11,778 kg (2023). Se was measured at 7,988 kg (2015) and calculated as 7,663 kg (2019) and 7,351 kg (2023). Conclusion: This shows that most heavy metals would increase steadily from 2015 to 2023. However, Se would decrease by 7.9%. This analysis was conducted with EMEP/EEA’s emission factors due to the limited emission factors in South Korea. Co-firewood pellets in coal-fired power plants cause the emission of heavy metals. For this reason, emission factors at air pollution control facilities would be presented and the replacement of wood pellets would be needed.