Non-cancer risk evaluation using a multidimensional strategy owing to groundwater fluoride and iron in a semi-arid region near the Indo-Bangladesh international frontier

Abstract

Abstract Groundwater quality in the semi-arid Hili border region at Indo-Bangladesh border was investigated in the post-monsoon season of 2021, succeeded by probabilistic health risk assessment of fluoride (F-) and iron (Fe) intake that breached respective safe limits in several samples. All water samples were found to be potable in terms of Ca2+, Mg2+, Cl-, SO42-, NO3- but F- and Fe exceeded prescribed safe limit for drinking in about 48% and 7% samples. Almost all the water samples were found to be good for irrigation in terms of Sodium Absorption Ratio (SAR), Soluble Sodium Percentage (SSP), Keely’s Index (KI), %Na and Magnesium ratio (MR). The Principal Component (PCA) /Factor Analysis (FA) identified three factors influencing groundwater quality, explaining about 71.8% of total variance and indicated that groundwater quality was primarily influenced by geochemical factors. Carbonate and silicate weathering were mainly responsible for dissolution of minerals in groundwater. Non-carcinogenic risk due to cumulative impact of F- and Fe intake was in the order of THI Children>THI Infant>THI Adult. As per Monte Carlo simulation run with 5000 trials to ascertain the order of probabilistic health risk, the most dominant governing factors behind non-carcinogenic risk caused by F- and Fe intake were their concentration (Ci) followed by ingestion rate (IR), and exposure duration (ED).