| Summary: | 碩士 === 國立成功大學 === 環境醫學研究所 === 87 === Recently, the application of incineration to municipal solid waste has been given much attention. Incineration possesses several advantages as a municipal solid waste disposal technology : (1) toxic components of municipal solid waste can be converted to harmless compounds or, at least, to less harmful compounds; (2) the volume of municipal solid waste is great reduced by incineration; (3) Heat recovery makes it possible to recover some of the energy produced by the combustion process; (4) less land needed. From the environmental standpoint, incineration can be the best method of disposing of municipal solid waste.
Some occupational exposure researches from incinerator indicates that the possible exposure to heavy metals is also a subject of public debate. So, we want to evaluate how much heavy metals the workers working in incinerator exposure. We optimize the sampling strategy for personal exposure measurements and biological monitoring of workers. After collecting the personal exposure and biological samples , we do analysis by ICP-Ms and graphite AAS. Then we will develop a risk assessment model to determine the carcinogenic and non-carcinogenic risk of occupational heavy metals exposure.
We choose three incinerators, A B and C, being the study subject according it's rated incinerating volume. Using cyclone sampler to proceed personal exposure and collecting the end of work urine to do biological monitoring. We have sampled twice individual for B and C incinerator in the normal operating situation, and three times for A incinerator when it was at normal operating situation, stopping burning for maintaining and stopping burning for checking. We collected 140 respirable dust samples, 87 blood samples and 174 urine samples. At the same time we also collected 103 questionnaires in order to gather some information about the incinerator workers. There are 13 female in the three incinerators and the average age of the workers is 32 years old. The working time in incinerator are form 1 mouths to 4 years, the most of workers are graduate from junior college.
The respirable dust concentrations' range is 0.010-1.323mg/m3, and the average respirable dust concentrations in incinerator B was significance higher then incinerator A and C. Between the different work group, in the incinerator A the maintenance group's average concentration (0.056±0.193 mg/m3) is significance higher then management group's average concentration (0.045±0.579 mg/m3) is the lowest. Beside, The respirable dust concentration at the different operation situation was not appear the different. The concentration of eight kinds of heavy metals (Pb,Cr,Cd,Hg,As,Zn,Ni,Cu) in respirable dust are very low. The concentration of three kinds heavy metals(As ,Cr, Hg) are different between the three incinerators, and the concentration of Cr, Ni, As, Hg are dissimilar at the different operation situation. We measure Pb concentration in the blood and Cr, Cd, Ni in the urine samples. There were 7 workers who's Cd concentration in urine and 5 worker who's Cr concentration being excess BEI(5,10mg/g creatinine). The PbB and CrU concentration were different between incinerator and the operation situation. According the unit risk about As, we assessment the carcinogenic risk for incinerator workers and the carcinogenic risk of occupational As exposure is 10-fold then normal population. The other heavy metal be assessed non- carcinogenic risk by using hazard index(HI), and all HI.are less 1 to show that the exposure to these heavy metal(Pb, Cd, Hg, Ni, Cr, Cu, Zn) dose not endanger the incinerator workers.
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