Spatial distribution and probabilistic health risk assessment of fluoride in groundwater of Angul district, Odisha, India

Abstract

Presence of fluoride (F−) in drinking water both at low and high levels causes serious human health hazard. In this investigation, 106 number of groundwater samples of Angul district (Odisha, India) were collected and analyzed using statistical, hydrogeochemical, spatial distribution and health risk assessment methods. About 28% of the collected groundwater samples, the concentration of F− exceeded the permissible limit set by WHO as well as Buero of Indian Standards (BIS). Apart from this, 13 % of the collected samples the concentration of F− varied from 2 to 3.4 mgl−1 and thus, highly harmful for human consumption. The human health risk assessment was carried out as recommended by the USEPA. In the study area, the calculated hazard quotient (HQ) caused by F− contamination varied from 0.0 to 2.12 and 0.0 to 3.92 for adults and children respectively. Almost 28.30% and 58.49% groundwater samples are exhibited non-carcinogenic health risk due to F− contamination for adult and children respectively. The non-carcinogenic health risk posed by F− to children is higher than adult. Further, F− exhibited a positive correlation with bicarbonate (HCO3−) alkalinity. The concentration of F− increases with pH, which indicating that higher pH augments the dissolutions of F− ions from metamorphic and sedimentary F− containing minerals of the study area. In addition, intensive uses of phosphate fertilizer, pesticides and industrial activities may be contributing as the other sources of F− in the groundwater.