Spatial distribution, exposure, and potential health risk assessment from nitrate in drinking water from semi-arid region of South India

Abstract

Elevated nitrate concentration in groundwater is a worldwide problem. Continuous exposure to high levels of nitrate in groundwater may cause adverse health effects among residents who use groundwater for consumption. Therefore, this study was conducted to identify the nitrate distribution and its potential health risk assessment from semi-arid region of Peddavagu in Central Telangana (PCT), South India. Groundwater samples were collected from thirty five locations and analyzed for nitrate and other water quality parameters. Nitrate (NO₃^-) in groundwater was observed to vary from 17 to 120 mg/L, with a mean of 58.74 mg/L. About 57% of samples exceeded the maximum acceptable limit of Indian drinking water standard. About, 40% of groundwater samples drinking water quality index (DWQI) is good, while 60% of groundwater falls in poor quality for drinking purposes. Health risk maps were created based on hazard quotient to quantify the potential health risk of the residents using US Environmental Protection Agency (US EPA) health risk assessment model. Health risk assessment revealed that mean total hazard index (HI_total) for men, women, and children were found as 1.42E + 00, 1.67E + 00, and 1.95E + 00, respectively. Results exhibited that children are at high health risk than men and women in the PCT. Further, the human exposure to the NO₃^- contaminated water was above the critical limit of non-carcinogenic risk.

Keywords:

• Drinking water quality index (DWQI)
• Health risk assessment (HRA)
• nitrate contamination
• Peddavagu in Central Telangana (PCT)
• South India

Acknowledgements

The author wish to thanks to the Editors and three anonymous reviewers for their constructive comments and suggestions which are greatly helped me to improving the quality of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was financially supported to Narsimha Adimalla by Department of Science and Technology (DST)-Science and Engineering Research Board (SERB), Govt. of India, under the Fast Track Young Scientist project no. SR/FTP/ES-13/2013, entitled “Delineation of high fluoride bearing groundwater zones by hydro – litho & pedogeochemical investigations in the north eastern parts of Medak district, Telangana, India”.