RESEARCH ARTICLE Environmental contamination by heavy metals and associated human health risk assessment: a case study of surface water in Gomti River Basin, India Ramsha Khan 1 & Abhishek Saxena 1 & Saurabh Shukla 1 & Selvam Sekar 2 & Venkatramanan Senapathi 3 & Jianhua Wu 4,5 Received: 4 March 2021 /Accepted: 24 May 2021 # The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2021 Abstract The aim of the present study was to assess the status of heavy metal contamination and health risks associated with the use of water from River Gomti by millions of people. The value of the degree of contamination (C d ) was found to be ‘11.93’, signifying ‘high’ risk levels due to heavy metal contamination in River Gomti across an approximate stretch of 61 km including upstream, midstream, and downstream locations of Lucknow city. The potential sources of heavy metal pollution in River Gomti include both sewage and industrial effluents, being transported by drains which overflow into the river. The heavy metals were found to have low mobility owing to the ‘near neutral’ pH of river water. The findings from the human health risk assessment revealed that the hazard index associated with non-carcinogenic risks exceeded the permissible limits at all sampling stations. The highest health risk was found at Bharwara sewage treatment plant discharge point, downstream of Lucknow city signifying the elevated levels of heavy metal in the river water post treatment from Bharwara STP. The results of carcinogenic risk assessment suggested that children were more susceptible to health risks, and immediate remedial measures are required to control the elevated levels of heavy metals at all the sampling stations. Keywords Heavy metal toxicity . River Gomti . Lucknow city . Carcinogenic risks . Non-carcinogenic risks Introduction Rivers are categorized amongst the most vital sources of fresh- water for human sustenance (Shukla et al. 2020). Excessive stress has accumulated on rivers due to the rapid pace of development and urbanization including the discharge of mu- nicipal and industrial effluents affecting the existence of hu- man and aquatic population (Li et al. 2021; Li et al. 2020; Shukla and Saxena 2020a; Li 2020; Sreebha and Padmalal 2011). The rivers traversing through urban agglomerations Responsible Editor: Lotfi Aleya * Abhishek Saxena abhisheksaxena79@gmail.com * Saurabh Shukla saurabh.shukla2020@gmail.com Ramsha Khan ramshaokhan@gmail.com Selvam Sekar geoselvam10@gmail.com Venkatramanan Senapathi venkatramanansenapathi@gmail.com Jianhua Wu wjh2005xy@126.com; wujianhua@chd.edu.cn 1 Faculty of Civil Engineering, Institute of Technology, Shri Ramswaroop Memorial University, Barabanki, UP 225003, India 2 Department of Geology, V.O. Chidambaram College, Tuticorin, Tamil Nadu, India 3 Department of Disaster Management, Alagappa University, Karaikudi, Tamil Nadu 630002, India 4 School of Water and Environment, Chang’an University, No. 126 Yanta Road, Xi’an 710054, Shaanxi, China 5 Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education, Chang’an University, No. 126 Yanta Road, Xi’an 710054, Shaanxi, China Environmental Science and Pollution Research https://doi.org/10.1007/s11356-021-14592-0