Mechanism of arsenic enrichment and mobilization in groundwater from southeastern Bangladesh: Water quality and preliminary health risks assessment

Md Atiqur Rahman; Md Abu Bakar Siddique; Rahat Khan; A H M Selim Reza; Abdul Hadi Al Nafi Khan; Md Ahedul Akbor; Md Saiful Islam; Asma Binta Hasan; Md Irfanul Hasan; Iftakhar Bin Elius

doi:10.1016/j.chemosphere.2022.133556

Mechanism of arsenic enrichment and mobilization in groundwater from southeastern Bangladesh: Water quality and preliminary health risks assessment

Chemosphere. 2022 May:294:133556. doi: 10.1016/j.chemosphere.2022.133556. Epub 2022 Jan 7.

Affiliations

¹ Department of Geology and Mining, University of Rajshahi, Rajshahi 6205, Bangladesh.
² Institute of National Analytical Research and Service (INARS), Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhanmondi, Dhaka 1205, Bangladesh. Electronic address: sagor.bcsir@gmail.com.
³ Institute of Nuclear Science and Technology, Bangladesh Atomic Energy Commission (BAEC), Savar, Dhaka, 1349, Bangladesh. Electronic address: rahatkhan.baec@gmail.com.
⁴ Institute of Nuclear Science and Technology, Bangladesh Atomic Energy Commission (BAEC), Savar, Dhaka, 1349, Bangladesh. Electronic address: nafiwre10@gmail.com.
⁵ Institute of National Analytical Research and Service (INARS), Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhanmondi, Dhaka 1205, Bangladesh.
⁶ Department of Soil Science, Patuakhali Science and Technology University, Patuakhali 8602, Bangladesh.
⁷ Institute of Nuclear Science and Technology, Bangladesh Atomic Energy Commission (BAEC), Savar, Dhaka, 1349, Bangladesh.

PMID: 35007611
DOI: 10.1016/j.chemosphere.2022.133556

Abstract

To understand the mechanistic pathway of arsenic (As) enrichment and mobilization in groundwater (southeastern Bangladesh) and to evaluate the water quality as well as associated health risks, a suite of systematically collected groundwater samples (depth: 17-61 m) were analyzed. Arsenic concentrations (μg L^-1) in the groundwater samples were ranged from 6 to 581 with a mean value of 199 which is significantly higher than the recommended values. The assessment of water quality using entropy water quality index and irrigation water quality indices revealed that the groundwater in the studied region was not recommended for drinking and irrigation, respectively with few exceptions. Dominant water types in the studied area were Ca-Mg-HCO_3, Na-HCO₃, and Na-Cl types. Various forms of water-rock interactions, leaching of evaporates, and the confined nature of the aquifer mostly control the hydro-chemical parameters. Fe/Mn bound As are likely to be released in the aquifer through the dissolution of carbonate minerals of Fe/Mn while the higher degree of water-rock interaction and probable oxidation of organic materials helped to elevate As concentration. The probable longer residence time of groundwater guided by topographic slope and the neighboring clayey aquitard govern the As mobilization in the aquifer. Probabilistic health risk assessment revealed that groundwaters from the studied area can cause both non-carcinogenic and carcinogenic health risks.

Keywords: Arsenic contamination; Entropy and irrigation water quality indices; Groundwater quality; Human health risks; Hydro-geochemistry; Spatial and vertical distributions.

MeSH terms

Arsenic* / analysis
Bangladesh
Environmental Monitoring
Groundwater*
Water Pollutants, Chemical* / analysis
Water Quality

Substances

Water Pollutants, Chemical
Arsenic