Humic acids from endemic arsenicosis areas in inner Mongolia and from the Blackfoot-disease areas in Taiwan: A comparative study

The physical and chemical properties of humic acids (HA) extracted from dri nking waters from the endemic arsenicosis areas in Inner Mongolia and from the Blackfoot disease (BD) areas in Taiwan are studied by using AAS (atomic absorption spectrophotometry), ICP-MS (inductively coupled plasma emission -mass spectrometry), IR (Infrared spectroscopy), FR (fluorescence spectrome try) and TLS (total luminescence spectroscopy) in order to shed light on th e pathogenesis of BD with the concern as to whether the disease may eventua lly occur in arsenicosis-affected areas in the Mainland of China. Ames test and lipid peroxidation experiments were also conducted on these HA samples . It is found that water samples from the two regions are high in arsenic ( As) with strong fluorescence and apparent positive correlations between As content, fluorescence, pH and total dissolved solids (TDS). The water sampl es are similar in fluorescence spectra but differ somewhat in IR and TLS be tween the two regions. The difference may be a reflection of the difference in radicals and structure of the HA owing to different hydrogeological con ditions, and may also be related to the difference in their biological effe cts, i.e., HA from Inner Mongolia have a stronger ability to cause lipid pe roxidation while HA from Taiwan exhibits a more prominent effect of mutatio n with respect to TA98(+/- S9).