*Koyomi NAKAZAWA1, Osamu NAGAFUCHI1, Kanji OKANO1, Ken'ichi OSAKA1, Etsuji HAMABATA1, Keisuke IKEDA1, Akifumi YOSHIDA1, Javzan CHOIJIL2, Jamstram TSUGTBAATAR2
(1.University of Shiga prefecture, 2.Institute of Geography Mongolian academy of sciences)
39 ground water samples were collected from wells in August to September 2013 in South gobi, Mongolia. Sampling sites were located in Oyu tolgoi (Cu mine and Au mine), Tavan tolgoi (coal mine) which were large-mining activity has been conducted. In addition, samples are collected in northern area of Mongolia for comparison. PH, EC, the concentration of fluoride (F?), chloride (Cl?), sulfate (SO42?), nitrate (NO3?), sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), mercury (Hg), manganese (Mn), nickel (Ni), zinc (Zn), cadmium (Cd), lead (Pb), chromium (Cr), arsenic (As), selenium (Se), lithium (Li), aluminium (Al), vanadium (V), cobalt (Co), molybdenum (Mo), indium (In), antimony (Sb) and tellurium (Te) were measured. We charactrize the water quality and human helath risk. In Tavan tolgoi and Oyu tolgoi, HQ (Hazard Qoutient) showed > 1, which is considered at risk. In Oyu tolgoi, HQ of NO3- (29.6+-20.1 mg/l) and As (6.63+-5.69ug/l) showed > 1. In Tavan tolgoi, HQ of NO3- (47.1+-36.2 mg/l) showed > 1 and it contribute the most (44 %) to the average HI, followed by As (17 %, 2.57+-3.72ug/l) and Mo (17 %, 17.8 +-11.1ug/l). On the other hand neither HQ nor HI not showed > 1 in Northern area. Result from the nitrogen and oxygen stable isotope ratio, NO3- contamination in Oyu tolgoi and Tavan tolgoi was caused from livestock waste.