Heavy Metals in afforested Mangrove Sediment From the World's Largest Delta: Distributional Mapping, Contamination Status, Risk assessment and Source Tracing

Authors

Md Saifur Rahman
Moshiur Rahman
Yeasmin N Jolly
Md Kamal Hossain
Sanjida Afrin Semme
Bilal Ahamad Paray
Takaomi Arai
Jimmy Yu
M Belal Hossain

Publication Date

5-4-2024

Journal

Marine Pollution Bulletin

Abstract

This study aims to assess seasonal and spatial variations, contamination status, ecological risks, and metal sources (Ni, Pb, Cr, Cu, Mn, and Zn) in human-afforested mangrove sediments in a deltaic region. Five sampling locations were sampled during dry and wet seasons. Heavy metal concentrations followed the order: Mn > Zn > Ni > Cr > Cu > Pb. Metal loads, except Cu and Pb, were higher during the dry season, aligning with national and international recommendations. Sediment quality guidelines, contamination factor, geoaccumulation index, enrichment factors, and pollution load index indicated uncontaminated sediment in both seasons. Potential ecological risk assessment showed low risk conditions in all sites. However, modified hazard quotient indicated moderate pollution risk from all metals except Pb. Analysis suggests anthropogenic sources, particularly evident near shipbreaking yards in Sitakunda. While initially uncontaminated, ongoing metal influx poses a potential risk to mangrove ecosystems.

Keywords

Contamination, Distribution, Ecological risk, Heavy metals, Mangrove sediments, mHQ