Pollutants and Water Management. Группа авторов

and Technology, Central University of Jharkhand, Ranchi, Jharkhand, India

      Ajeet Kumar Singh Environmental Informatics and Spatial Modelling Lab (EISML), Department of Ecology and Environmental Sciences, School of Life Sciences, Pondicherry University, Pondicherry, Puducherry, India

      Anubhuti Singh Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, Uttar Pradesh, India

      Gurudatta Singh Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, Uttar Pradesh, India

      Priyanka Singh Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, Uttar Pradesh, India

      Ram Kishore Singh Department of Nanoscience and Technology, Central University of Jharkhand, Ranchi, Jharkhand, India

      Sukhendra Singh School of Biochemical Engineering, IIT (BHU) Varanasi, Varanasi, Uttar Pradesh, India

      Rupika Sinha Department of Biotechnology, MNNIT, Allahabad, Uttar Pradesh, India

      K.S. Sista Research and Development, Tata Steel, Jamshedpur, Uttar Pradesh, India

      Swati Department of Botany, BHU, Varanasi, Uttar Pradesh, India

Indu Tripathi Department of Botany, University of Delhi, New Delhi, India Department of Environmental Studies, University of Delhi, New Delhi, India

      Shashank Tripathi Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, Uttar Pradesh, India

      Bhawna Verma Department of Chemical Engineering and Technology, IIT (BHU), Varanasi, Uttar Pradesh, India

      Satyam Verma Environmental Informatics and Spatial Modelling Lab (EISML), Department of Ecology and Environmental Sciences, School of Life Sciences, Pondicherry University, Pondicherry, Puducherry, India

      Jitesh Narottam Vyas Central Water and Power Research Station, Pune, Maharashtra, India

      Amit Kumar Yadav School of Environment and Sustainable Development, Central University of Gujarat, Gandhinagar, Gujarat, India

      Deepak Yadav Chemical Engineering Department, Harcourt Butler Technical University, Kanpur, Uttar Pradesh, India

      Monika Yadav Department of Environmental Studies, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, India

Part I Water Pollution and Its Security

1 Water Security and Human Health in Relation to Climate Change: An Indian Perspective

       Ravishankar Kumar, Prafulla Kumar Sahoo, and Sunil Mittal

       Department of Environmental Science and Technology, Central University of Punjab, Bathinda, Punjab, India

1.1 Introduction

      The capacity of a population to maintain sustainable access to sufficient quantities of acceptable quality water to ensure human well‐being, livelihood, socio‐economic development, protection against water‐borne and water‐related disasters, and to preserve ecosystems is termed as water security (UN Water 2013). Water demand is increasing with time due to the booming population, rapid industrialization, rampant urbanization, and extensive agricultural practices. In the world, nearly 785 million people lack a safe drinking water service, including 144 million people dependent on surface water (WHO 2019). Nearly, 1.8 billion people use feces contaminated drinking water sources and have a high risk of contracting cholera, dysentery, typhoid, and polio (WHO 2019). It has been estimated that the world population will be around 9 billion by 2050 and water availability will be less than the current availability (UN WWDR 2015). As per a World Health Organization (WHO) estimation, by 2025, 50% of the global population will be living in water scarcity areas (WHO 2019). By 2050, the global water demand is expected to increase by 20–30% as compared with the current scenario, due to growing demand in the domestic and industrial sectors (UN WWDR 2019). The estimation of the United Nations World Water Development Report (2016) indicated that more than 40% of the global population could be living in severe water stress areas by 2050.

Presently, the world's two most populous countries, India and China, are facing severe water security problems. However, the conditions are more critical in India both in terms of quantity and quality due to a lack of required infrastructure, health services, and management. India has only 4% of the world's freshwater but accounts for 16% of the global population. India ranked 120th out of 122 nations in water quality index and 133rd among 180 nations in water availability (NITI Aayog 2018). Approximately 21% of diseases are related to water among all diseases of the country (Snyder 2020). As per UNICEF and WHO (2012) estimates, approximately 97 million Indians do not have access to safe water. Further, the findings of the 2011 census revealed that 138 million rural households had access to safe drinking water, whereas 685–690 million people lacked access to safe drinking water. An ironic fact is that more than 41% of the rural population (out of 833 million people) of India own mobile phones but have no access to potable water which is a basic need. Only 18% of the rural population have access to treated water (Unitus Seed Fund 2014; Forbes India, 2015).

      The NITI Aayog report (2018) also said that India is facing its worst water crisis in history, which is only expected to become worse as the country's water demand is projected to be twice the available supply by 2030. The report said that 600 million currently face high to extreme water shortage, with around two lakh people dying every year due to inadequate access to potable water. The increasing water shortage will also affect the gross domestic product (GDP) of the nation, with the country suffering a loss of up to 6% of GDP in 2030 (NITI Aayog 2018).

      The quality of both river and groundwater is deteriorating at a rapid pace, making water scarcity more severe. Even toxic heavy metals like uranium, lead, cadmium, selenium, and so on are also reported in groundwater samples from various states (Chowdhury et al. 2016; Kumar et al. 2018, 2020; Sharma et al. 2020). This may lead to severe consequences for water resources. According to the IDSA report (2010), it has been reported that India is expected to become “water‐stressed” by 2025 and “water‐scarce” by 2050.

      Further, climate change is also affecting the water security of India as rising temperature affects the Himalayan glaciers as well as altering the monsoon pattern. The combination of these two factors affects the level of river water due to the melting of glaciers and intense rainfall. Further, groundwater resources are also affected directly and indirectly by the alteration of these factors. High water temperature, changes in timing, intensity, and duration of precipitation are the significant consequences of climate change which can further affect the water quality. The alternate pattern of precipitation leads to floods and droughts, which play an important role in the degradation of water quality by adding a quantum of concentrated pollutants. As per the World Bank report (2018), climate change can affect 6% GDP of some regions due to water security, resulting in migration and conflict. As per the United Nations Convention to Combat Desertification (UNCCD), by 2030, due to climate change impacts on water scarcity, 24–700 million people may be displaced from some arid and semi‐arid places.

      The achievement of water security in the future will be a very challenging task. This chapter describes in detail the current situation and future challenges regarding water security along with prospective health changes. Further, the impact of climate change on water security and health has been analyzed. The available opportunities are also discussed to manage future challenges related to water security.

1.2 Quantity of Available Water Resources in India

The