05276nas a2200457 a 4500 20260817163615.0 080625s2007 th uu|m rtt 0| a1eng d .b12007614 AIT Diss. no.EV-07-8 Vitchayut Tupwongse Assessment of metals contents in a water reservoir of Northern Thailand Pathum Thani, Thailand : Asian Institute of Technology, 2007 166 p. : ill. (some col.) Dissertation ; no. EV-07-8 A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Environmental Engineering and Management Inter-University Program on Environmental Toxicology, Technology and Management Thesis (Ph.D.) - Asian Institute of Technology - Chulabhorn Research Institute - Mahidol University, 2007 The assessment of metals concentrations in freshwater resource had been done at Phayao Lake, Phayao province, Northern Thailand, which is a major water resource for drinking water supply, agriculture, and household use. This study was divided into 3 parts which are field survey, the assessment of dietary exposure from fishery products from the lake, and the cytotoxicity testing of the selected metals in two human cell lines. The field survey samplings were carried out in 3 periods (February, May, and August) in 2005. Metal analysis was performed by using inductively coupled plasma mass spectrometer (ICP-MS). Concentrations of Mn and As in lakewater ranged from 40-382 and 0.68-8.79 ug/L whereas the U.S.EPA. secondary 'maximum concentrations limit for drinking water (Mn) and WHO (As) guidelines for drinking water are 50 and 10 ug/L, respectively. Concentrations of some metals (A1, Cr, Mn, and Fe) in water were found to be higher in the area where water flowed from a small river into the lake than in other areas. The highest metal concentrations were found in the period of the dry season (May 2005). Among different sampling sites, the patterns of metal accumulations were different. Estimated consumption of fishery product from the lake was calculated and the results indicated that the concentrations of metals in these products were lower than the recommended average daily dietary intake. Therefore, the consumption of fish and pond snail from this water resource may not pose a risk of metal toxicity. However, monitoring of the levels of Mn and As in lakewater should be carried out routinely so that appropriate prevention of contamination from these toxic metals can be implemented. For In vitro study, the investigation of cytotoxic effects of a mixture of selected metals As, Mn, and Pb in human neuroblastoma SH-SY5Y cells was done. The cytotoxic effect of individual metal in SH-SY5Y cells was studied using XTT cell viability assay. Treatment of As, Mn, or Pb caused a dose-dependent increase in cytotoxicity in SH-SY5Y cells. The lowest concentration that cause less than 5 % cell death was selected, to be used in multiple exposure studies, 0.05 uM (3.75 ug/L) for As, 0.1 uM (20.27 ug/L) for Mn, and 0.5 uM (27.5 u/L) for Pb. It was noted that these selected concentrations of As and Mn were within the ranges found in Phayao Lake. The results demonstrated that single exposure to each metal at the selected concentration had no significant cytotoxic effect whereas the combination of Mn and Pb or As caused a significant increase in cell death (about 15%) in comparison to exposure to a single metal. The combination of all three metals, As, Mn, and Pb significantly increased cytotoxicity to 25% of control in SH-SY5Y cells. These results indicated that simultaneous exposure to non-cytotoxic levels of multiple heavy metals can potentially enhance the risk of toxic effect in in vitro study Reservoirs Thiland Phayao Water-supply Thailand Phayao Heavy metals Jutamaad Satayavivad, Chairperson Preeda Pakpian, Examination Committee Piyajit Watcharasit, Examination committee Chulabhorn Research Institute, Scholarship donor Mahidol University, Scholarship donor Asian Institute of Technology (CRI-MU-AIT), Thailand, Scholarship donor Asian Institute of Technology. Dissertation ; no. EV-07-8 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B00532 .b12007614 mnait u 240401 0 080625 m a u 0 mnait mnait mnarc 20 40 Barcode : 30050120725808 CREATED : 2007-02-28 RECORD # : i12517641 LPATRON : 1025752 LCHKIN : 2015-02-05 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 7 TOT RENEW : 3 Barcode : 30050120725816 CREATED : 2008-06-25 RECORD # : i1256350x LPATRON : 1024654 LCHKIN : 2013-11-12 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 6 TOT RENEW : 2 Barcode : 30050160004379 CREATED : 2016-02-02 RECORD # : i12877098 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 9232 9232 0 0 0 0 MAIN MAIN mnait 2026-08-17 50.00 0 AIT Diss. no.EV-07-8 30050120725808 2026-08-17 16:36:15 1 2026-08-17 20 0 0 0 0 MAIN MAIN mnait 2026-08-17 50.00 0 AIT Diss. no.EV-07-8 30050120725816 2026-08-17 16:36:15 2 2026-08-17 20 0 0 0 0 MAIN MAIN mnarc 2026-08-17 0 AIT Diss. no.EV-07-8 30050160004379 2026-08-17 16:36:15 2026-08-17 40