How monitoring sewage could prevent a return of the coronavirus
In their efforts to stave off a second wave of COVID-19, scientists from around the world have turned to a new ally: sewage.
In the United Kingdom, the Netherlands and Spain, researchers are poring over samples of wastewater for signs of the coronavirus, which is believed to be shed in human feces.
Given that many people with the virus are asymptomatic and will not be tested for the disease, scientists say sewage could act like a COVID-19 early warning system.
For more information, see UNEP’s factsheet on COVID-19, wastewater and sewage
"Monitoring water resources, including wastewater, has always been very important," says Birguy Lamizana, a United Nations Environment Programme (UNEP) wastewater expert. "This has became even more important in the context of the COVID-19 pandemic."
Countries have long monitored sewage, which is laden with traces of the food people eat, the medicine they take, and the disinfectants they use. Wastewater monitoring has been used for decades to assess the success of vaccination campaigns against poliovirus, for example.
But in many developing countries, a lack of funding, regulations and technical know-how makes the process a challenge, even in normal times. As states marshal resources to fight the COVID-19 pandemic, experts say wastewater monitoring has fallen completely by the wayside in many places, leaving them vulnerable to a return of the coronavirus.
Experts also worry that without monitoring, medical waste contaminated with COVID-19 may find its way into sewer systems and municipal water supplies. There are concerns as well that coronavirus-tainted refuse from slaughterhouses and animal markets, including manure, fur and blood, could spark outbreaks of the disease.
“During the COVID-19 health crisis it’s important to treat waste management, including medical, household and other hazardous waste, as an urgent and essential public service to minimize possible secondary impacts on health and the environment,” says Lamizana.
Uphill battle in the global south
The challenges with monitoring sewage are part of a larger waste management crisis in the developing world. Globally, the number of urbanites who lack safely managed sanitation increased from 1.9 billion in 2000 to 2.3 billion in 2015, costing US$223 billion a year in medical care and lost productivity, according to a study by the World Resources Institute.
Recent sanitation data from 15 cities in the global south also shows that almost two-thirds of sewage and human waste is unsafely managed, with access to safe sanitation lowest in South Asia and sub-Saharan Africa.
With COVID-19 cases rising in many parts of the developing world, Lamizana says it’s important for states to take an integrated approach to waste management that focuses on recycling and reducing waste. Government should also concentrate what’s known as wastewater segregation, which sees black water, gray water and water laden with toxic chemicals siphoned off into separate municipal streams.
“An integrated waste management approach focusing on sustainable wastewater and solid waste management is essential,” says Lamizana.
Nature is in crisis, threatened by biodiversity and habitat loss, global heating and toxic pollution. Failure to act is failing humanity. Addressing the current coronavirus (COVID-19) pandemic and protecting ourselves against future global threats requires sound management of hazardous medical and chemical waste; strong and global stewardship of nature and biodiversity; and a clear commitment to “building back better”, creating green jobs and facilitating the transition to carbon neutral economies. Humanity depends on action now for a resilient and sustainable future.