Surveillance of Groundwater Quality in Relation to Geochemistry in Selected Districts of Kerala, with Special Reference to Fluoride and Arsenic Contamination,

Abstract

Groundwater is considered the safest source of drinking water, and 89% of the world's population relies on it. India is one of the largest consumers of groundwater worldwide, accounting for around one-fourth of the global share and exceeding 230 km3/annum. Globally, and particularly in India, arsenicosis and fluorosis are two emerging health problems linked to groundwater. Fluoride and Arsenic are present in the earth's crust, but elevated concentrations in the groundwater are the result of human-triggered activities. The combination of Fluoride and Arsenic may cause health consequences. Fluoride, Arsenic, salinity, and heavy metals were assessed quantitatively and qualitatively in this study under various climatic, geological, and topographical circumstances. This study evaluated the occurrence and distribution pattern fluoride, arsenic, salinity, and heavy metals in distinct climatic, geological, and topographical conditions. The study also focused on the quantitative availability of groundwater reserves in the two Districts. The groundwater availability in Palakkad District is 434.17 MCM and 249.32 MCM in Malappuram District during the study period. Fluoride contamination is severe in the eastern part of the Palakkad District and south eastern part of the Malappuram District. Arsenic pollution is also dominant in these regions. In contrast to the coastal system, the inland system has a higher salinity. Mg-Ca-HCO3 type water predominates due to rock-water interaction in the Palakkad District, while precipitation-induced calcium sulphate type water predominates in the MalappuramDistrict. Heavy metal contamination was severe in both Districts, and Cd and Pb pollution were dominant. The mean heavy metal pollution index (HPI) indicates that the highest heavy metal incidence occurred in the Pr period and the least during the Po period in the study area. Cd, Pb, and Ni have concentrated in urban areas in the study area, whereas iron-mediated issues are higher in coastal region associated with fluvial deposits. The metal index was high in Malappuram and highly concentrated along the coastal line. WQI indicates 48% of the groundwater is poor in Palakkad,while the majority of the Malappuram groundwater is of good quality. 11% of the groundwater in Palakkad is unsuitable for irrigation. High Mg ion concentration, high alkalinity, and a lengthy groundwater residence period in the aquifer are the factors that enhanced the solubility of Fluoride. Silicon oxide is the dominant component in mineral samples. The XRD and XRF data reveal that the hornblende-biotite gneiss is indicative of the Fluoride source. Moreover, the trace amounts of Fluorite and Arsenic in the mineral sample are indicative of these contaminants in the study area. The mineralogical study of Fluoride and Arsenic contaminated areas demonstrated that the causes of Fluoride and the majority of Arsenic contaminations were geological in nature.