In-Vitro Determination of Arsenic Bioavailability in Contaminated Soil and Mineral Beneficiation Waste from Ron Phibun, Southern Thailand: A Basis for Improved Human Risk Assessment

摘要: The post-ingestion bioavailability of arsenic (As) in alluvial soil and mineral beneficiation waste from Ron Phibun, Nakhon Si Thammarat Province, Thailand has been investigated using a physiologically-based extraction test (PBET). method utilises synthetic leaching fluids closely analogous to those the human stomach small intestine, upon which duration ambient temperature experimental procedure are also directly based. Replicate analyses Phibun alluvium samples holding 1406 2123 μg As g-1 respectively indicated an average absorption 11.2% (of total As). Gross increased 18.9% following translocation through simulated small-intenstine regime. Higher gross (35.7%) was recorded during PBET analysis flotation sample c. 2% As. Within- between-site variations can principally be ascribed mineralogical factors, notably relative abundances sulphide, arsenide, arsenate oxide hosts within soil/flotation matrix. provides potentially valuable mechanism for refining risk assessments sites subject natural or anthropogenic contamination. Through substitution values with input data relate specifically bioavailable As, calculations derived established models such as US-EPA package Risk Assistant may prove more realistic, thus facilitating improved cost-benefit site remediation options. Assessment risks associated potable water consumption contaminated ingestion at signified that latter could constitute significant exposure pathway than recognised previously. Further evaluation precise levels inhabitants residing on As-rich covers much district is, therefore, warranted.