Water is a fundamental human need and access to clean water a basic human right, according to the United Nations. Drinking water quality is therefore essential for public health; however, 10% of the global population do not have access to improved drinking-water sources.
In 2017, 5.3 billion people used safely managed drinking-water services (WHO). However, at least 2 billion people used a drinking water source contaminated with faeces, being at risk of disease transmission such as cholera, diarrhoea, dysentery, hepatitis A, typhoid, and polio, according to the same organization. Water contamination, however, does not only occur in the form of microorganisms, chemical pollution can also occur, if there is an inadequate management of urban, industrial, and agricultural wastewater.