Health risk assessment of nitrates and fluorides ingestion and geochemical evaluation of groundwater characteristics in semi-arid regions

The natural and anthropogenic alterations in groundwater are exposing human health to nitrates and fluorides ingestion, especially in arid and semi-arid regions. The study focused on the depth-wise assessment of groundwater aquifers ( n = 150) and non-carcinogenic health risks to vulnerable population in semi-arid regions of South, North and Central Punjab, Pakistan. The water quality index delineated the shallow and moderate aquifers unfit for human consumption with high values in North region (88%) as “very poor” to “unsuitable for drinking” as compared to the South and Central regions. The North region (56%) was categorized as high risk zone for nitrate pollution (2.48 times), while fluorides affected aquifers of the South region. The piper diagram elucidated bicarbonates prominence in the North and South, while bicarbonates and chlorides type in the Central region aquifers. The Gibbs plot attributed geogenic exchanges like silicate-weathering and ion-exchange mechanisms as dominant groundwater features. The non-carcinogenic health risks for nitrates were higher in the North region (Children: 1.36E+00 > Adult: 1.34E+00 > Infants: 1.08E+00) while for fluorides, South region (Children: 1.18E+00 > Adults: 1.17E+00) was at risk. The overall health impact was higher in South > North > Central for Children > Adults > Infants, respectively. Nitrates and fluorides made children (age 1–12 years) vulnerable to non-carcinogenic health risks in these regions. It is crucial to prioritize efforts to treat and reduce groundwater pollution to protect human health and the environment.