Heavy metal contents in sediment at monitoring stations Nha Trang, Vung Tau and Rach Gia (1998-2014)

Abstract

The analysis results of heavy metals in sediment at monitoring stations Nha Trang, Vung Tau and Rach Gia from 1998 to 2014 showed that heavy metals varied widely: in Nha Trang station (Zn: from 14.7 to 99.5 µg/g; Cu: from 3.9 to 26.0 µg/g; Pb: 4.7 to 39.3 µg/g; As: 0.13 to 16.07 µg/g ; Cd: 0 to 4.8 µg/g; Hg: 0.02 to 2.76 µg/g), Vung Tau station (Zn: from 7.0-65.1 µg/g; Cu: from 1.6 to 21.8 µg/g; Pb: 2.2 to 27.6 µg/g; As: 0.1 to 7.3 µg/g ; Cd: 04.5 µg/g; Hg: 0.02 to 1.24 µg/g) and Rach Gia station (Zn: from 16.6 to 113.1 µg/g; Cu: from 1.8 to 19.1 µg/g; Pb: 2.4 to 43.2 µg/g; As: 0.14 to 13.84 µg/g; Cd: 0 to 4.8 µg/g; Hg: 0.02 to 0.93 µg/g). However, there was no difference between the survey conducted in March-April and AugustSeptember. Heavy metal contents in sediment at Nha Trang and Rach Gia stations were always higher compared to those in Vung Tau station. Overall, by the time, the variation trend of heavy metal contents in all three stations was not clear although Zn contents in Nha Trang and Rach Gia stations had the trend of decreasing. In generally, the sediment quality in term of heavy metals at three stations was good and suitable for the aquatic life compared to National Technical Regulation on Sediment Quality in Vietnam.