The Content of Heavy Metal in the Labu Riverbed Sediments: An Assessment of the Level of Pollution Applying Sediment Quality Guidelines and Geoaccumulation Index

Abstract

River bed sediments from thirteen (13) sampling stations, from Labu River were collected in June and December 2014. The aim is to identify the source and ascertain the current levels of heavy metal pollutions. The selected heavy metals (Cr, Cu, Fe, Ni, Zn, As, Cd and Pb) were analysed by using Inductively Couple Plasma Mass Spectrophotometry (ICPMS). Metals were statistically analysed and compared with Dutch/Malaysia Sediments Quality Guidelines (Target and intervention values) and the Canadian Sediment Quality Guidelines (ISQG and PEL). Geoaccumulation index (Igeo) was calculated and metals were classified. The results showed that the mean value for Cr is 19.74±10.36 mg kg^-1, Cu (7.33±2.35 mg kg^-1); Fe (7636.39±26.38 mg kg^-1); As (11.67±3.59 mg kg^-1); Cd (0.097±0.03 mg kg^-1) and Pb (26.23±5.33 mg kg^-1). The compared sediment guidelines revealed that Cr (51.55 mg kg^-1) in SW9, Pb in SW1 (36.43 mg kg^-1) and SW13 (37.42 mg kg^-1) and As in all of the stations (SW1-SW13) did not meet the Canadian ISQG and were polluted. The geoaccumulation index (Igeo) showed that, Cr (-3.38±0.17), Cu (-3.22±0.12), Ni (-3.37±0.24), Zn (-2.14±0.23), Cd (-3.38±0.17) and Pb (-3.22±0.12) were practically uncontaminated. However, As (2.14±0.13) was classified as moderately contaminated. Based on mean concentrations of heavy metals with the compared Sediments Quality Guidelines (SQG) and Index, it is concluded that As is the heavy metal of concern in the Labu catchment. There is need for the authorities to pay more attentions to sediment pollution problem due to As and address riverbed sediment pollution problems in the different locations as indicated by ISQG due to anthropogenic influences from the KLIA, Dengkil sand mine and Agriculture developments projects in the study area.