TITLE:
Heavy Metal Pollution and Spatial Distribution in Surface Water and Sediments of Dhamrai Upazila, Bangladesh
AUTHORS:
Shahtaj Karim, Riyadul Islam, Khaleda Afrin, Md. Rashedul Hasan
KEYWORDS:
Anthropogenic Contamination, Contamination Factor, Geo-Accumulation Index, Heavy Metal, Pollution Load Index, Heavy Metal Pollution Index
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.8,
August
10,
2026
ABSTRACT: Rapid industrialization is transforming Dhamrai Upazila into a suburban hub near capital, Dhaka, with predominantly unplanned development. Industrial effluents are discharged into the Banshi, Gazikhali, and Dhaleswari Rivers, raising concerns about contamination, particularly heavy metals. This study investigated the spatial distribution and pollution assessment of heavy metals (Cr, Mn, Fe, Co, Ni, Cu, Cd, Pb, As, and Al) in surface water and sediments using the Heavy Metal Pollution Index (HPI), Geo-accumulation Index (Igeo), Contamination Factor (CF), and Pollution Load Index (PLI). Seven surface water samples and corresponding sediment samples (15 cm and 60 cm depths) were collected from upstream to downstream locations and analyzed using an inductively coupled plasma mass spectrometer (ICP-MS). Mean heavy metal concentrations decreased in the order of Fe > Mn > Cu > As > Ni > Pb > Cr > Cd in water and Mn > As > Cr > Cu > Pb > Ni > Co > Al > Fe > Cd in sediments. The HPI indicated largely unpolluted surface water, whereas the Igeo revealed moderate to extreme contamination. The CF indicated moderate to very high contamination, whereas the PLI suggested polluted conditions. The Igeo classified sediments as uncontaminated to extremely contaminated, particularly for As, Pb, Cd, and Cu. Similarly, CF indicated moderate to very high contamination at 15 cm, while PLI confirmed sediment pollution at both depths, with lower contamination at 60 cm. Correlation analysis and PCA indicated that Fe, Mn, and Al were primarily of geogenic origin, whereas Cr, Co, Ni, Cu, Cd, and Pb were mainly derived from anthropogenic sources. Although As is primarily geogenic in Bangladesh, its elevated concentrations and statistical association with anthropogenic metals suggest both geogenic and anthropogenic influences. These findings emphasize the need for effective pollution control through industrial effluent treatment, wastewater management, agricultural runoff control, and integrated river basin management (IRBM) in the study area.