summarize the following passage Over the past few decades, access to improved water and sanitation facilities has become a significant challenge for many countries in the developed and developing world. Access to improved water and sanitation is crucial to improving public health and achieving sustainable economic growth. Globally, 2.4 billion people and 663 million people are still lack improved sanitation facilities and drinking water sources in 2015, respectively (WHO/UNICEF, 2015). This situation makes it worse for human development and well-being. It is a significant cause of child mortality through diarrhoea and other sicknesses. For example, an estimated 842,000 deaths occur each year due to diarrhoea and other illnesses associated with inadequate water, sanitation and hygiene (WHO, 2016). In 2010, the UN General Assembly confirmed that sanitation and drinking water are human rights. Later, the resolution called the member states and international development organisations to provide better infrastructure, particularly developing countries, to provide safe and clean drinking water and sanitation for all (UN, 2010)