Lee, Yi Te creator Preeda Pakpian Chairperson Fukushi, Kensuke Examination Committee Nguyen, Cong Thanh Examination Committee text series technical report th Bangkok Asian Institute of Technology 2001 continuing eng 35 leaves By analyzing accumulated arsenic (As) in hair, As level can be identified for chronic arsenic toxicity. The relationship between arsenic levels and degree of toxicity is only very approximate. The objectives of this study are to observe the pH stability and biodegradability of arsenic-keratin complex in hair. The experiment was set up at different pH (4, 7, 10) and extraction time. The biodegradability test was carried in anaerobic condition. The arsenic concertration was measured by Atomic Absorpting Spectrophotometer associated with arsine hydride generator. In the pH range of 4 to 10, the predominant As3+ compound is neutral in charge, while the AS5+ species are negatively charged. The arsenic release percentage increased with the extraction time. The arsenic released in lower pH shown higher concentration than that of higher pH. For the biodegradability tes, it did not show any significant amount of arsenic. The pH and extraction time affects the arsenic-keratin complexes in hair. Nevertheless, compare wtih the intital arsenic concentration in hair, the released percentage is quite low, which signifies that arsenic-keratin complex(hair) is a stable compound. A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development Research Studies Project Report (M. Eng.) - Asian Institute of Technology, 2001 Arsenic Toxicology Arsenic Environmental aspects Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B00061 http://203.159.5.9/ait-thesis/detail.php?q=B00061 020118 20260818100350.0