Evaluation of the drinking water quality and potential health risks of nitrate and fluoride in Southwest Delhi, India

Abstract

ABSTRACT The present study was attempted to evaluate the water quality index (WQI) and also performed potential human health risk assessment i.e. Hazards quotient (HQ), Total hazard index (THI) of nitrate (NO3 −) and fluoride (F−) through ingestion of groundwater in pre-monsoon and post-monsoon seasons. The WQI classification showed that 56%, and 34% of groundwater resources were unfit for consumption in pre-monsoon and post-monsoon seasons. The HQ and THI of the non-carcinogenic hazards were computed using the potential health risk assessment of NO3 − and F−enriched groundwater. The findings showed that in adults, 26% and 36% of the water samples had high risk quotients for HQ-NO3 − and HQ-F−, respectively, while in children, 40% and 54% of the samples had risk quotients for HQ-NO3 − and HQ-F− above the permissible level. This suggests that F− contributes more to the non-carcinogenic risk than NO3 − in pre-monsoon. However, NO3 − adds more to the non-carcinogenic risk than F− in post-monsoon, as shown by the HQ-NO3 − and HQ-F− in 42% and 2% of samples for adults, and in 58% and 14% of samples for children, respectively. Children in the study area were more vulnerable to the non-carcinogenic effects of NO3 − and F− according to the findings. Total hazards index (THI) for adults and children in for NO3 − and F− were ranged from 0.34 to 8.61 (Avg. 1.68) and 0 to 8.20 (Avg. 1.75) in pre-monsoon season. Similarly, NO3 − and F− were ranged from 0.37 to 2.85 (Avg. 1.86) and 0 to 2.86 (Avg. 0.85) in post-monsoon season, respectively. The results of this study can improve effective environmental management measures for enhancing the groundwater quality and public health of the study area.