Assessing heavy metal pollution in surface sediments of saltmarshes in Liao he estuary

Soil samples at depths of 00 <10cm and 10-20cm were collected in Suaeda salsamarshes and bare areas from six saltmarsh sites in Liao he estuary. Contents of 7 heavy metals (As, Cd, Cr, Cu, Pb, Zn and Hg ) were determined to depict their soildepth distribution. The average contents were ((all in mg·kg-1):As 1223, Cd 033, Cr 6225, Cu 2429, Pb 2375, Zn 7412, Hg 0. Suaeda salsaarea maximal contents of As, Cd, Cr, Cu, Pb in top 10 cm soils appeared at Site D. Maximal As, Cd, Cu, Pb and Zn were observed in 10-20cm soil at Site E. Cr showed maximum content at Site D. Bare area maxima of As, Cr, Cu, Pb and Zn were observed in 0-20 cm soil at Site F, whereas Cd showed maximum at Site D. Heavymetal pollution in surface sediments was low. Geoaccumulation Index Assessment showed the following pollution classification: Cd>As>Cu>Zn>Pb>Cr>Hg. Ecological risk of surface sediments was found to be mainly due to Cd pollution.