유치원 교실에서 공기 중 박테리아와 곰팡이 발생에 영향을 미치는 요인

박동욱,조경아,윤충식,한인영,박두용,Park Donguk,Jo Kyunga,Yoon Chungsik,Han Inyoung,Park Dooyong 한국환경보건학회 2004 한국환경보건학회지 Vol.30 No.5

Airborne bacteria, gram negative bacteria (GNB) and fungi were measured in 70 class of 17 kindergartens. The objective of this study is to identify the factors influencing airborne concentrations of bacteria, GNB and fungi using multiple regression analysis. The average concentrations of bacteria and fungi exceeded $1,000\;CFU/m^3$. The average of GNB was $3.7{\times}10^2\;CFU/m^3$. This results indicated that air of kindergartens was contaminated with microbes such as bacteria and fungi. ANOVA test found that the concentrations of bacteria, GNB and fungi were significantly different by the characteristics of weather (rain, after rain, sunny) sampling date (July, August, September and October), the location of sampling site (ground level and basement) and the location of toilet (inside class, nearby class and away class). Multiple regression tests concluded that sampling date, the scale of city where kindergartens are located, the location of sampling site and ventilation efficiency can significantly affect the airborne concentration of bacteria, GNB and fungi. Most of these factors could be related moisture. Environmental factors that can cause the increment of moisture should be controlled in order to reduce airborne concentration of bacteria, GNB and fungi. Legal actions concerning prohibition on the presence of toilet inside class and ventilation criteria should be taken.

방수 스프레이 흡입 노출로 인한 급성 호흡기 중독 사례 및 원인 고찰

박동욱,최예용,Park, Donguk,Choi, Yeyong 한국환경보건학회 2012 한국환경보건학회지 Vol.38 No.6

Background: In Korea, a healthy 36-year-old man developed acute interstitial pneumonitis soon after inhaling a waterproofing spray which he had applied at home to his outdoor jacket. Objectives: The objectives of this study were to review cases of varying degrees of respiratory toxicity and poisoning in connection with the use of waterproofing spray and summarize major reasons for cases of poisoning. Methods: We searched articles reporting on a combination of a waterproofing agent and/or respiratory symptoms, including acute respiratory syndrome, lung injury, pneumonia, pulmonary toxicity, and respiratory disease. Results: We reviewed a number of cases of varying degrees of respiratory toxicity and poisoning resulting from inhalation of waterproofing spray containing fluorocarbon co-polymer, solvents and propellants reported in a variety of countries. The literature searches concluded that among the ingredients of waterproofing agents, fluorinated polymer may cause acute respiratory health effects. Conclusion: Environmental policy should be implemented in order to prevent consumers from using household and industrial products including waterproofing agents. In addition, a national surveillance system should be created to collect cases of poisoning caused by the use of consumer products.

가습기 폐질환(Humidifier Lung)의 환경적 원인 인자 고찰

박동욱,Park, Donguk 한국환경보건학회 2013 한국환경보건학회지 Vol.39 No.2

Background: In Korea, there is low awareness of the respiratory health problems caused by the use of humidifiers, leading to a lack of governmental measures. Objectives: The objectives of this study were to review cases of varying degrees of humidifier lung and fever in connection with the use of humidifiers and to summarize the probable environmental agents causing these cases. Methods: We searched all articles reporting on humidifier lung, humidifier fever, and humidifier diseases caused by the use of a humidifier both at home and in the workplace. Results: We summarized a number of cases of varying degrees of respiratory diseases resulting from inhalation of water mist of humidifiers containing various species of bacteria and fungi and their toxins. Type of respiratory disease connected with humidifier lung includes interstitial pneumonitis, hypersensitivity pneumonitis, fever and several respiratory symptoms. Non-tuberculous mycobacteria (NTM), Actinomycetes, endotoxins and contaminated humidifier water were the most commonly suspected probable environmental agents causing humidifier lung. In Korea, the use of humidifier biocide is suspected as a likely cause of fatal lung injury including death and lung transplantation. Conclusion: Governmental policy should be devised and measures including a national surveillance system should be taken to prevent humidifier lung caused by the use of humidifiers.

Impact of Microplastics on Rice Productivity, Soil Physicochemical Properties and Greenhouse Gas Emissions in a Rice Paddy during Cultivation: A Pot Experiment

Donguk Park(박동욱),Eunsu Park(박은수),Seongwoo Choi(최성우),Juhee Lee(이주희),Yeomyeong Lee(이여명),Sang Yoon Kim(김상윤) 한국토양비료학회 2021 한국토양비료학회 학술발표회 초록집 Vol.2021 No.11

Microplastics (MPs), small particle sizes (< 5 mm), are widely distributed in soil environment, recently increasing global attention. Agricultural materials including mulching film, soil conditioners, and greenhouse materials were major sources of MPs to be incorporated into agroecosysyems. MPs can influence soil physical, chemical, and biological properties, which may affect biogeochemical cycling in agricultural soils, potentially influencing greenhouse gas emissions (GHGs) and deteriorating crop productivity. However, few studies were carried out to investigate the effects of MPs on greenhouse gas emissions and productivity as well as soil quality during rice cultivation. In the pot experiment, different levels of MPs (0, 0.025%, 0.05%, 0.1% wt wt<SUP>-1</SUP> which roughly corresponded to 0.5~2 Mg ha<SUP>-1</SUP> in the field) that are mixed with the proportion of mulching film (60% wt wt<SUP>-1</SUP>), pesticide bottle (35% wt wt<SUP>-1</SUP>) as high-density polyethylene (HDPE), and other plastics (5% wt wt<SUP>-1</SUP>) including PP, PVC, PET were incorporated at the presence or absence (no cultivation, only added MPs) of rice plant with triplicate before the rice transplanting. We monitored GHG emissions (CO₂, CH₄, and N₂O), rice growth characteristics and yield, soil physical (qualitative and quantitative analyses of leachate) and chemical properties (pH, total C, N, extractables etc.) during cultivation. Our results showed MPs incorporation increased over all GHGs emissions during cultivation, showing much higher emissions in the absence of rice plant. MPs additions also suppressed rice growth and mainly reduced tiller numbers and height with increasing MPs application levels. Soil physical properties were also deteriorated by MPs additions, showing an obvious decrease in leachates at the higher levels of them. Our results indicate MPs incorporations can deteriorate overall soil quality including physical and chemical properties, which lead to significant decrease in rice productivity. Moreover, MPs can potentially increase GHGs emissions, probably due to the increased decomposition rate of MPs incorporated in rice paddy. Conclusively, our findings suggest that MPs might have a potentially hazardous impacts in rice paddy ecosystem. Therefore, the mitigation strategies of MPs should be urgently developed for a better and sustainable agricultural environment.

Textbook Evaluation Program

박동욱(park donguk),백삼균(PAIK Samkyun),곽덕훈(Dukhoon Kwak),박경애(Kyeongae PARK) 한국방송통신대학교 미래원격교육연구원 2005 평생학습사회 Vol.1 No.2

Because of the large number of students and textbooks at Korea National Open University (KNOU), no study has been conducted to evaluate the quality and content of textbooks for more than 30 years. We developed an evaluation method for textbooks that was appropriate for a distance learning university with so many students. The objective of this study was to report the first term results of the textbook evaluation method. 382 textbooks developed by professors of KNOU from 20 departments were evaluated. The evaluation method was composed of three consecutive steps. In the first step, all students who received a grade higher than C+ (39,449 students in the first term and 47,227 students in the second term) were invited to respond to the evaluation sheets, which were sent to them by e-mail. The response rate by department ranged from 31.5 % to 57.3 % in the first term and 26.9 % to 53.9 % in the second term, which was large enough to represent the student population. All students who responded to the questionnaire were provided with a chance to win a prize. This seemed to encourage students to participate. Forty textbooks (two textbooks per department x 20 departments) were screened by student evaluators and thus step two began. External adjunct professors, using these 40 textbooks in the regional study centers of KNOU, were responsible for the second step of the evaluation. Two external adjunct professors per textbook were randomly selected and asked to evaluate the textbook using the same evaluation sheets as the students. A correlation test indicated that the evaluation scores by students in the first step, and adjunct professors in the second step, were not significantly different (r= 0.534 in the first term and r=0.662 in the second term). This result proved that students could fairly evaluate the textbooks. Finally, The Textbook Publication Committees (TPC) monitored each step in the evaluation process to ensure that they were appropriately conducted, and then selected the four best textbooks(20 books in the second term) on the basis of score and qualitative judgment. This study concluded that the KNOU evaluation system for textbooks could be applied to distant or open universities with tens of thousands of students.

Microplastic Incorporations to Paddy Soil as Consequences for Soil Properties, Greenhouse Gas Emissions, and Rice Productivity: A Pot Experiment

Eunsu Park(박은수),Donguk Park(박동욱),Juhee Lee(이주희),Yeomyeong Lee(이여명),Sang Yoon Kim(김상윤) 한국토양비료학회 2022 한국토양비료학회 학술발표회 초록집 Vol.2022 No.10

대학 캠퍼스 주변 호프집, PC방, 당구장의 실내 PM_2.5 농도를 통한 ETS 노출 수준 평가

이재환 ( Jae Hwan Lee ),박동욱 ( Donguk Park ),하권철 ( Kwonchul Ha ) 한국산업보건학회 (구 한국산업위생학회) 2016 한국산업보건학회지 Vol.26 No.4

Objectives: The aims of this study were to determine the indoor level of environmental tobacco smoke (ETS) and to assess the implementation rate of smoke-free laws at hospitality venues around a university campus by measuring particulate matter smaller than 2.5 ㎛ (PM_2.5) as an indicator of ETS. Materials and Methods: We measured indoor PM_2.5 concentrations at 20 PC game rooms, 20 pubs, and 20 billiards halls using Sidepak AM510, a direct reading portable real time monitor, from October to December 2015. Results: Smoking was observed in 65% of the PC game rooms, 10% of pubs, and 85% of billiards halls. The average PM_2.5 concentrations were 98.2 ㎍/㎥, 29.0 ㎍/㎥, and 134.2 ㎍/㎥ at PC game rooms, pubs, and billiards halls, respectively. PM_2.5 concentrations in PC game rooms and billiards halls were 2 to 2.7 times higher than the 24-hour exposure standard for outdoor PM_2.5 (50 ㎍/㎥) by the Ministry of Environment. Conclusions: Although a smoking ban has been implemented for PC rooms and pubs, smoking is still taking place in many of these places. More stringent legal action is required for successfully protecting patrons and workers from secondhand smoke exposure. A ban on smoking in billiards halls should be introduced as quickly as possible.

시설 내 탄산가스 시비 시 시설 대기환경의 변화가 알스트로메리아(Alstroemeria) 생육에 미치는 영향에 대한 고찰

이선진 ( Seonjin Lee ),성원석 ( Wonsuk Sung ),박동욱 ( Donguk Park ),정필수 ( Pilsoo Jeong ) 한국농업기계학회 2022 농업기계공학 Vol.2 No.1

CO₂ fertilization is very critical for plants in a greenhouse because CO₂ is insufficient after sunrise due to the photosynthesis. This study reported the variation of CO₂ concentration in greenhouse and the effect of greenhouse plants on CO₂ fertilization. Alstroemeria were cultivated in CO₂ fertilization greenhouse and non- CO₂ fertilization greenhouse (Control house). To supply CO₂, we set a catalyst-type CO₂ generator at fertilization greenhouse and it generated 0.36kg/h CO₂. The CO₂ concentration at CO₂ fertilization greenhouse was maintained about 640 ppm from 6:00 to 10:00. The result reported that CO₂ fertilization significantly increased the weekly yield and shoot length. There was slightly increase at total number of flowers and stem thickness despite of no statistical significance. According to these positive results, we considered that future studies would be aimed at experiments with bigger scale and more details.

고속철도 교량의 현장실험 및 감쇠비 개선에 따른 공진 시 동적응답의 분석

김성일(Sungil Kim),김현민(Hyunmin Kim),박동욱(Donguk Park) 한국철도학회 2013 한국철도학회논문집 Vol.16 No.4

작업환경측정 결과 데이터베이스를 활용한 직무노출매트릭스 구축을 위한 공정 표준화

최상준 ( Sangjun Choi ),박주현 ( Ju-hyun Park ),고동희 ( Dong-hee Koh ),박동욱 ( Donguk Park ),김환철 ( Hwan-cheol Kim ),임대성 ( Dae Sung Lim ),성예지 ( Yeji Sung ),고경윤 ( Kyoung Yoon Ko ),임지선 ( Ji Seon Lim ),서회경 ( Hoekye 한국산업보건학회 2023 한국산업보건학회지 Vol.33 No.1

Objectives: The purpose of this study is to standardize the process code of the work environment measurement database (WEMD) for the construction of a job-exposure matrix (JEM). Methods: The standard process code (SPC) was reclassified based on process similarity and drawing upon the code used in the existing K2B. It was supplemented through review by industrial hygiene experts. In addition, an index word database related to SPC was created and used for SPC search. A pilot evaluation project was conducted by experts to evaluate the validity of the newly reclassified standard process code. Results: A total of 70 final SPCs were developed, including 31 processes related to the construction industry. Using the Shiny program, we developed a standard code finder that can be used on the web (https://kscf.shinyapps.io/scf_app/). As a result of the pilot evaluation, it was determined that it was easier to search for standard codes than previous codes, so it was highly utilized. Conclusions: It is expected that JEM construction using industry-process information drawing on WEMD data will be possible using the 70 newly standardized process codes.