Fluoride contamination in drinking water and associated health risk assessment in the Malwa Belt of Punjab, India

Abstract

• We report fluoride levels in 745 groundwater samples from the Malwa Belt, Punjab. • 49.7% of the samples exceeded the WHO guideline value of 1.5 mg L −1 . • High fluoride levels are observed in industrial and agricultural predominant areas. • Health risk assessment was computed for different age groups through ingestion. • Children and teenagers are more vulnerable to high fluoride exposure than infants. This study highlights fluoride concentrations, the associated non-carcinogenic risk for various age groups (infants, children, teenagers, adults, and senior citizens), and physicochemical parameters in 745 groundwaters from 7 districts of Punjab. The fluoride levels varied from 0.1 to 17.5 mg L −1 with an average value of 2.1 ± 1.8 mg L −1 and a median of 1.5 mg L −1 , and 49.7% of samples exceeded the permissible limit of 1.5 mg L −1 prescribed by the Bureau of Indian Standards and World Health Organization. The mean fluoride concentrations in the seven districts followed the order of Bathinda (3.2 mg L −1 ) > Muktsar (2.6 mg L −1 ) > Faridkot (2.4 mg L −1 ) > Mansa (2.3 mg L −1 ) > Fazilka (1.3 mg L −1 ) > Barnala (1.1 mg L −1 ) > Moga (1.0 mg L −1 ). Fluoride in groundwater showed a significant relationship with total dissolved solids in all the districts except the Moga district. The results showed that mean hazard quotients (HQs) were greater than 1 for all age groups in Bathinda, Mansa, Faridkot, and Muktsar districts. The non-carcinogenic risk among the investigated age groups was in the order of children > teenagers > adults > senior citizens > infants. The results revealed that the groundwater is unfit for human consumption. Further investigations are required in the study region to measure the daily fluoride exposure in other drinking water sources such as canal water, municipal reverse osmosis water, and bottled water.