| Summary: | 博士 === 國立清華大學 === 化學系 === 96 === Heavy environmental burden in Taiwan is partly due to its limited accessible land and high density population. To pursue economic development, numerous industrial parks were established. Residential area sometimes overlaps with industrial area as a result of improper space planning and utilization. Use of large amounts of toxic metals by the factories will jeopardize the neighboring residents should improper operation and control occur resulting in emission of toxic metal pollutants (TMPs). TMPs are prone to accumulative in and difficult to be degraded by living beings. Compared to other toxic pollutants, TMPs have greater impact to the environment and possess potential crisis. TMPs might transmit via the air in solid or/and gaseous form and directly threat the health of neighboring residents and workers in the park. TaoYuan County (TYC) and the Hsinchu Science-based Industrial Park (HSIP) are the two investigating area in this thesis. We use standard methods from Taiwan EPA for heavy metal sampling and analyses, i.e. with an inductively coupled plasma mass spectrometer for sensitive determination of trace analytes (As, Be, Cd, Cr, Cu, Hg, Mn, Ni, Pb, W, Ga, and In). Furthermore, we use statistical methods of factor analysis and cluster analysis to examine the measured data, aiming to understand the distribution of TMPs in ambient air around industrial parks and to reveal suspected sources. We use cancer slop factor from the Toxicity Criteria Database of the American Environmental Health Hazard Assessment to estimate the perpetual cancer risk from ambient TMPS to neighboring residents. The thesis contains five chapters. Chapter 1 describes the motive behind this research and the methods used. Chapter 2 is entitled “The impact to the distribution of heavy metals in ambient air at HSIP after the operation of a sludge-drying incinerator”. We found elevated levels of tungsten and mercury in ambient air when the sludge-drying incinerator was in operation. Chapter 3 is entitled “Distribution investigation and risk assessment of TMPs in ambient air around TYC industrial parks”. The regulated TMPs like Pb and Cd are compliant with Taiwan air quality regulations. Setting 10-5 as the targeted cancer risk, we recommend the air quality standard as following: 0.005 μg/Nm3 for As, 0.005 μg/Nm3 for Be, 0.005 μg/Nm3 for Cd, 0.05 μg/Nm3 for Ni, 1 μg/Nm3 for Pb, 0.0001 μg/Nm3 for Cr+6. The recommended values are from 1/10 to 1/100 of the current values. Chapter 4 is entitled “Distribution investigation and risk assessment of TMPs in ambient air around HSIPs”. The cancer risk from TMPs in ambient air to neighboring residents ranges from 5.5×10-4 to 6.8×10-4 with a mean value of 6.3×10-4. Cr+6 is the dominated contributing TMP. Excluding Cr+6, the cancer risk ranges from 1.3×10-5 to 3.4×10-5 with a mean value of 2.1×10-5. Chapter 5 summarizes the conclusions and perspectives for future.
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