Research on Radioactivity and Cytotoxicity of Emission Aerosol During Casting Process

• Main Authors: Chun-Chao, 張鈞超
• Other Authors: 賴全裕
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/56791250944275586160

碩士 === 中山醫學大學 === 職業安全衛生學系碩士班 === 100 === Casting process was indicated that easily to form the metal fumes and fugitive particle which was suspended in the metal foundry by the past literatures. However, the radioactivity of particulate characteristics was less Investigated. The effect of particulate characteristics with human, such as particle size, dose, concentration, radioactivity and heavy metal contribution were still unclear. For this reason, the research used the normal human lung fibroblast（WI-38 cells）to investigate the cytotoxicity from the particle sampled in the foundry by MTT assay. In addition, the research tries to clarify the contribution of each factor by statistical analysis. Two commercial foundries, copper or aluminum casting, were recruited in the research. A Micro-Orifice Uniform Deposit Impactor（MOUDI）was used to sample emission aerosols during casting processes. The filter papers were weighing to know the particle distribution in the foundry. Then, the measurement of total a and b radioactivity of aerosols had been carried out by using a proportional counter by Nuclear Energy Institute. Apart from this, particle responded in the air by clean the work site was another way which human exposure to the particle. The research try to use 6-stage Anderson Impactor with particle collected from casting work site to do positive-pressure re-suspension sizing. The sizing particle by this system was analyzed the heavy metal by Inductively Coupled Plasma Mass Spectrometry（ICP-MS） by Industrial Technology Research Institute. In order to clarify the particulate cytotoxicity by MTT assay, the study calculated the concentration that workers actually exposed to according to the average work time and tidal volume. The data of characteristics of particle and result of MTT assay were analyzed by statistics assay. The result show that based on cut off size of MOUDI, the two peaks of copper casting were 1.8 and 5.6 μm; on the other hand, the two peaks of aluminum casting were 1.8 and 18 ~ μm. Moreover, the peak aerosol total a and b radioactivity of the two casting foundries was in the range of 0.1～0.32 μm. The major metal compositions of copper casting were Al, Si, Cu in order. Additionally, the major metal compositions of aluminum casting were Al, Si and Sr in order. The MTT assay result show that the WI-38 cells apoptosis in 1X dose level but proliferated in 10X dose level when exposed to casting emission aerosol. All the data were collected for statistics analysis; the study found that dose level, particle size, radioactivity and heavy metal were significantly related to the cell viability. However, the co-linearity in the exposed factors interfere the result to become none significantly by multivariate logistic regression assay. If the research wants to know the relationship of the exposed factors more clearly, it seems that the factors need further classified according to their related.