Evaluation of airborne infection disease risk by integrated multi-zone airflow and infection transmission modeling

• Main Authors: Chun-Chieh Lin, 林俊杰
• Other Authors: Yu, Hsin
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/74218424820490702684

碩士 === 國立宜蘭大學 === 土木工程學系碩士班 === 104 === In recent years, the type and intensity of airborne infection disease is gradually increased in the world, and results in serious threat to human’s health and safety. The duration of people’s indoor activity is beyond 90% of all day. The outbreak of airborne infection will occur if infectors stay in indoor space. In order to predict the risk of airborne infection disease, epidemiology scholars have established infection numerical model to assess the risk of airborne infections. Wells-Riley equation is commonly used to assess risk of airborne infection in research. Wells-Riley equation has two assumptions that indoor air is uniformly mixed and is steady-state. The assumptions are difficult to correspond with reality. Therefore, the integrated model combined computer fluid dynamics (CFD) and Wells-Riley equation to predict the risk of airborne infection is conducted. But the CFD method is difficult to analyze the pollutant concentration in multi-zone space during a long time and the inhaled dose of susceptible persons. The integrated model combined the multi-zone airflow model and the Wells-Riley equation to predict the airborne infection risk is suggested by literature. This study investigate the feasibility of integrated model combined the multi-zone airflow model and the Wells-Riley equation to assess the risk of airborne infection, and propose to assess risk of airborne infection by carbon dioxide exposure. The study includes two parts, part one is to verify the accuracy of simulating pollutant concentration by using CONTAM. The carbon dioxide concentration monitored in Engineering Building 203 and Construction Management Laboratory is compared with the simulated value from CONTAM. The results of the coefficient of determination between measured data and simulated data in the experiments of Engineering Building 203 and Construction Management Laboratory are 0.96 and 0.99 separately. It indicates that the CONTAM has high accuracy to simulate pollutant concentration in indoor space. Part two is to use the integrated model to analyze the risk of airborne infection and compared with the infectors from the actual results of the literature. The first case is an outbreak of measles in elementary school. The results of the first case show that the predicted infectors of simulation and of investigation are 28 and 21 in first generation. The predicted infectors of simulation and of investigation are 31 and 24 in second generation. The predicted infectors of simulation and of investigation are 59 and 46 in combining the first and the second generation. Error rate is 26.2%, 24.1%, and 22.7%in above three scenarios separately. The second case is an outbreak of measles in a pediatric clinic. The simulation of CONTAM results in the criteria exposure of infection according to the reality of infection. The results indicate that a susceptible person will be infected if the exposure is above 156.75 min·ppm.