Distribution, toxicity load and risk assessment of heavy metals in the groundwater of Dhemaji, Assam, India

• Published in: Chemosphere (Oxford) 2024-06, Vol.358, p.141979-141979, Article 141979
• Main Authors: Yadav, Shailesh Kumar, Attry, Binud, Shukla, Sudeep, Dutta, Shruti, Sharma, Khushboo, Rajak, Rajeev, Gupta, Aparna, Baruah, Bidyutjyoti, Ranjan, Rakesh Kumar
• Format: Article
• Language: English
• Subjects: Carcinogenic risk; Dhemaji; Drinking Water - analysis; Drinking Water - chemistry; Environmental Monitoring; Groundwater - chemistry; Human health; Humans; India; Metal spatial distribution; Metals, Heavy - analysis; Metals, Heavy - toxicity; Multivariate analysis; Non-carcinogenic risk; Pollution indices; Risk Assessment; Seasons; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - toxicity
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2024.141979

Metal contamination in drinking water has drawn attention since it gravely jeopardizes human health. This study was conducted in pre- and post-monsoon season in 2021 at Dhemaji, Assam, India. It characterized metal pollutants in groundwater, their distribution, possible sources, and evaluated the potential toxicity and associated health risk assessment. The seasonal mean concentration of Fe in both seasons is observed highest followed by Mn, Zn, Cu, As, and Ni. Furthermore, the metal concentrations during pre-monsoon are comparatively higher. The geogenic processes and agricultural practices are the major sources of groundwater metal contamination as evident from the statistical analysis. The different pollution indices viz. Heavy-metal Pollution Index (HPI), Heavy-metal Evaluation Index (HEI) and Degree of Contamination (Cd) suggested that groundwater is not suitable for drinking uses. The Heavy Metal Toxicity Load (HMTL) suggesting As, Co, Mn and Hg should be removed from the groundwater to ensure safety. Water pollution indices (WPI) suggest that Fe, Mn, As and Ni are the main pollution-causing metals in the study area which may be restored under the BIS and WHO limit by diluting the water. The human health risk has been calculated by carcinogenic and non-carcinogenic risk assessment. The non-carcinogenic risk for adults and children is within the threshold limit. The carcinogenic risk shows that continuous exposure of As and Ni may give rise to cancer among adults and children in the region. Therefore, comprehensive groundwater quality monitoring with well-planned treatment should be needed to provide safe and clean drinking water in the studied area. [Display omitted] •Heavy metal distribution and evaluation in the groundwater during pre and post-monsoon seasons at Dhemaji, Assam.•The average value of metals (As, Fe, Mn, Ni and Hg in both seasons) surpassed the WHO and BIS limits.•Most of the pollution indices showed that groundwater is not suitable for drinking uses.•Natural and anthropogenic inputs significantly control metals in groundwater.•justified that As and Ni can cause cancer in adults and children due to prolonged consumption of contaminated water.