Urbanisation is increasing in many countries, leading to the establishment of 33 megacities, representing huge water demand which is increasingly difficult to supply, exemplified by the recently avoided Day Zero event in Cape Town (2018) and the ongoing water crisis in Chennai, India. The ongoing growth of megacities could lead to the potential for further Day Zero events in countries ill-equipped to deal with such a situation. This study analyses the water supply and demand situations in 12 megacities hosting 194 million people.
Pathogenic viruses represent one of the greatest threats to human well-being. As evidenced by the COVID-19 global pandemic, however, halting the spread of highly contagious diseases is notoriously difficult. Successful control strategies therefore have to rely on effective surveillance. Here, we describe how monitoring wastewater from urban areas can be used to detect the arrival and subsequent decline of pathogens, such as SARS-CoV-2.
