In 2019, research into using wastewater to monitor health was understudied and underperformed. Fast forward one year and one global pandemic, and public agencies like the CDC and NIH are helping to fund and organize wastewater testing programs across the U.S., such as the National Sewage Surveillance Interagency Leadership Committee.
Now, looking back at the pandemic, one of the (many) unintended consequences is the revelation that municipal wastewater can be successfully used as a diagnostic tool to explore a surprisingly broad range of health indices.
In a new paper, Arizona State University researchers highlight how a technique known as wastewater-based epidemiology (WBE) can be used to not only assess factors influencing community-wide health but also help achieve a number of ambitious objectives outlined in the United Nations Sustainable Development Goals.
“Whereas most of these efforts today are still focused on containing the pandemic locally, it is time to take stock of what else can be accomplished using WBE to advance the human condition and sustainability globally,” said Rolf Halden, director of ASU’s Biodesign Center for Environmental Health Engineering and co-author of the study. “The first inventory of global wastewater infrastructure presented in our paper represents an initial and important step toward creating a healthier and more equitable future for human populations around the world.”
Halden’s study, the largest and most comprehensive assessment of wastewater infrastructure around the world to date, examines about 109,000 municipal wastewater treatment plants in 129 countries, serving 2.7 billion people worldwide, roughly 35% of the global population.
Although 80% of the population is served by municipal waste treatment systems in high-income countries, the researchers identified around 60 countries in which less than 40% of the population is served. The study notes that areas lacking centralized sewerage infrastructure, particularly in low-income countries, are “doubly disadvantaged”—at risk of poor hygiene and deprived of the early-warning benefits of WBE.
UN goals for sustainable development
In 2015, UN member states approved the 2030 Agenda for Sustainable Development, which comprises 17 specific goals to meet social, economic, and environmental development milestones. According to the ASU team, their new study demonstrates that WBE could be used to effectively track the progress made toward achieving over half of these goals.
As part of the study, the researchers conducted an in-depth literature survey of existing sewerage infrastructure, population demographics and a range of health-related biomarkers available in wastewater that could be leveraged to further the UN goals. They subsequently identified 25 different classes of biomarkers that can provide valuable health statistics on community levels of hunger, stress, cardiovascular disease, pulmonary afflictions and cancer.
For example, scientists can examine the mortality rate attributed to unsafe water, unsafe sanitation and lack of hygiene—goal 3.9.1—by tracking pathogens and related prescribed drugs and biomarkers in wastewater. Endogenous biomarkers of starvation can shed light on the prevalence of undernourishment (goal 2.1.1); while alcohol-related chemical biomarkers such as ethyl sulfate could inform targets for limiting alcohol consumption per capita (goal 3.5.2).
Beyond biomarkers, the WBE technique can be used to quantify stress metabolites and psychotropic drugs as possible indications of high suicide risk/rate. The more thorough, real-time identification of drug-resistant pathogens and antimicrobial-resistant genes could help in the fight against antibiotic resistance, which the UN calls a global health and development threat.
The ASU scientists found that WBE can also assist in the management of chemical risks like microplastics, endocrine-disrupting agents and a broad range of contaminants, including volatile organic compounds indicative of air pollution and environmental toxins like arsenic.
“The enhanced power of WBE for comprehensive health monitoring has significantly strengthened the case for extending sanitation infrastructure across the globe to safeguard human health as well as critical ecosystems. The new study also demonstrates the usefulness of the technique for helping society meet many of the United Nation’s goals toward a healthier and more sustainable world,” the researchers conclude.