Bioaccumulation and Ecological Risk Assessment of Heavy Metal Contamination (Lead and Copper) Build Up in the Roots of Avicennia alba and Excoecaria agallocha

Abstract

Mangrove roots play an important role in reducing heavy metal pollution in their surroundings. This study aimed to assess the bioaccumulation and ecological risk assessment of heavy metal pollution in mangrove roots. Mangrove root samples consisting of two species (Avicennia alba and Excoecaria agallocha) were collected from two observation stations in the mangrove ecosystem of Payung Island, Banyuasin District, South Sumatra, Indonesia. Heavy metal concentrations were measured by atomic absorption spectrometry. Then, statistical analysis was carried out by one-way analysis of variance (ANOVA). Ecological risk assessment used the bioconcentration factor (BCF), geoaccumulation index (Igeo), contamination factor (Cf), and pollution load index (PLI). On the basis of the results, the highest sediment heavy metal concentration at station 2 was Pb amounted to 13.57 ± 0.46 mg/kg, and Cu amounted to 11.08 ± 0.38 mg/kg. In turn, the highest heavy metal concentration of mangrove roots in E. agallocha species for Pb amounted to 2.89 ± 0.033 mg/kg and A. alba for Cu amounted to 10.57 ± 0.38, BCF was classified as exclusion (BCF < 1), except for the BCF of Cu station 1, which was classified as hyperaccumulator (BCF > 1). Igeo shows that the level of pollution is not contaminated (Igeo < 0), and Cf shows low pollution (Cf < 1), except Cf Pb station 2 is classified as moderate pollution. Conversely, PLI is included in the category of not polluted (PLI < 0). Mangrove roots play an important role in reducing heavy metal pollution in the surrounding area. Therefore, an in-depth understanding of heavy metal dynamics can be the basis for designing effective coastal environmental conservation strategies.