An assessment of metals contamination in Kemaman mangrove sediment during pre and post-monsoon seasons

Abstract

An assessment of metals contamination in Kemaman mangrove sediment during pre and post-monsoon seasons were conducted. The surface sediments were collected from 10 sampling point from Chukai mangrove forest during pre-monsoon and post-monsoon seasons and were analyzed for Al, Fe, Cr, Mn, Cu, Cd, Pb and grain size. During pre­ monsoon, the average concentration of Al, Fe, Cr, Mn, Cu, Cd and Pb were 2.02 ± 0.8%, 0.79 ± 0.43%, 263.89 ± 306.08µgi 1 dry weight, 31.82 ± 17.82µgg- 1 dry weight, 4.88 ± 1 2.98µgg- dry weight, 0.02 ± 0.01 µgg- 1 dry weight and 6.26 ± 2.8µgg- 1 dry weight, respectively. During post monsoon, the average concentration of Al, Fe, Cr, Mn, Cu, Cd and Pb were 2.54±1.1%, 0.84±0.38%, 37.12±12.26µgg- 1 dry weight, 26.05±6.16µgi 1 dry weight, 3.85±1.57µgg- 1 dry weight, 0.02±0.0lµgg- 1 dry weight and 7.44±3.42µgg- 1 dry weight, respectively. Enrichment factor and normalization was used to point out the level of pollution. During pre-monsoon, the enrichment factor (EF) and normalization indicated that only Fe, Cd and Pb were from natural resources, while all metals except for Cr originated naturally during post-monsoon. Comparison with background level indicates that the heavy metal concentrations on the study area are lower, except for Cr during both seasons. The statistical analysis of Pearson correlation matrix proved that there is a significant relationship between metal concentration and particle size. The concentrations of metals decrease with the decrease of particle mean size, suggesting their association with fine fraction of the sediment. All the metals except for Cr do not show any significant differences with seasonal changes (p > 0.05).