Presence of Arsenic anomalies in groudwater and its related with geological structures: case study of Dak Nong province

Abstract

Arsenic is the most carcinogenic element and its anomalies in groundwater in different regions of the world are the result of natural sources and/or due to human activity. High levels of arsenic in drinking water can lead to negative impacts on human health and ecosystems. In Dak Nong province, a number of Arsenic anomalies have been detected that are higher than the allowable value according to QCVN 01:2009/BYT, QCVN 02:2009/BYT (10 ppb) in some areas including Dak Mil, Cu Jut, Krong No, Dak Glong and Gia Nghia districts. In particular, in the area of Krong No district, an exceptionally high concentration of Arsenic was detected, exceeding the allowable value according to QCVN 09-MT:2015/BTNMT (50 ppb). This review paper presents the relationship between geological factors and the above-mentioned Arsenic anomalies. Study results have shown that Arsenic anomalies are related to three factors (1) fault tectonic activity (F13 fault and F29 fault zone); (2) mineralogy areas (mainly gold and pyrite mineralization), and (3) area of intrusive magma (geological vascular formations in cracks) and eruptions (Magma eruption locations in Cu Jut and Krong No districts). The result is a scientific orientation to study specifically and in detail the origin of As anomalies in Dak Nong province.