Can sleuthing city sewers for the coronavirus help halt a potential 2nd wave?
From mitigating contagions to combating the opioid crisis, surveilling wastewater should be part of every city’s public health toolbox
By Ari Goldfarb, CEO, Kando
Compared with the enormous challenges of the ongoing coronavirus pandemic, wastewater management may not seem like a particularly pressing priority on the global agenda. Yet the United Nations has identified proper wastewater management as one of the world’s top issues, and the fact is, wastewater and public health are actually deeply intertwined.
Surveilling and treating wastewater in municipal and industrial sewage systems is something akin to taking a “blood test” of a city, offering municipal leaders and utilities a wide range of vital health-related insights, including rates of infection and disease, drug use, and residents’ biological clocks. From mitigating contagions to combating the opioid crisis that has ravaged communities across the United States, wastewater epidemiology should be part of every city’s public health toolbox.
Here’s how sewage surveillance has already proven its worth – and why it’s critically important during the current crisis.
Drug Use and Opioids
While the coronavirus pandemic has infused the issue of wastewater management with new urgency, there’s already an extensive body of research documenting the links between what’s flowing underground and what illnesses may be spreading up above.
A recent study published in Scientific Reports, for instance, notes that waste from synthetic drug production “may harm aquatic life, can potentially contaminate the meat of cattle, which can affect the human food chain, and could further spread hazardous substances into the soil and waterways.”
Excretions of contraceptive pills are responsible for upwards of 10 million daily doses of synthetic estrogen in U.S. wastewater, and while only a fraction of those hormones make their way into drinking water, the fact that both recreational and prescription drugs infiltrate wastewater has spurred scientists to study different ways of removing traces of medicine from sewage systems. Two methods – granular activated carbon and ozonation – have been shown to reduce pharmaceutical concentrations by more than 95%.
Of course, knowing that traces of prescription drugs are present in wastewater systems – let alone actually removing them – requires continuous monitoring. Armed with up-to-date wastewater insights, local authorities can even direct resources toward specific areas with high rates of drug abuse and can actually alert authorities to drug making “factories” within city limits. For example, Sewage researchers at Arizona State University have detected traces of opioids in local wastewater, and in Tempe, where the university is based, researchers shared the findings of their sewage surveillance with paramedics, enabling first responders to predict trouble spots and distribute antidotes in problem areas.
Preventing Infectious Disease Outbreaks
What works for opioid crisis response also holds promise for preventing outbreaks of infectious diseases. Take polio, which has nearly been eradicated but is still endemic in Afghanistan and Pakistan.
Israel has firsthand experience in fending off polio with the help of sewage surveillance. In 2013, the country’s wastewater monitoring system, which had been installed in 1989, provided an early warning to officials of an outbreak in the town of Rahat. Because public health authorities were able to act quickly on the information, they were able to embark on a vaccination campaign and contain the outbreak, which ended in early 2014.
Hoping to build on that success, researchers around the world are now studying sewage to better understand the spread of the novel coronavirus, with scientists in Italy discovering that traces of the virus were present in that country’s wastewater by December – indicating that the virus may have arrived there far earlier than previously thought.
Thought it’s still early, and cities are still contemplating how they can make use of wastewater data to mitigate the pandemic, scientists’ work on the matter has helped spread awareness about the importance of sewage surveillance for this public health emergency and future ones. If scientists and public health authorities manage to replicate Israel’s experience with polio in 2013, officials could pinpoint infection hotspots and focus their resources and response – including lockdowns if necessary – on areas where the contagion is concentrated rather than pursuing a sweeping, one-size-fits-all approach, with their devastating repercussions.
In that respect, preliminary results from our pilot project in the Israeli town of Ashkelon, Israel offer promise in the struggle to contain the COVID-19 pandemic. The pilot project aimed at detecting outbreaks of COVID-19 in the coastal city by identifying traces of the coronavirus in the municipal sewage system, and indeed demonstrated the ability for early detection of outbreaks in wastewater. This city-scale pilot study also demonstrated the ability to locate hotspots down to specific neighborhoods and even city streets – again, helping avoid total lockdowns by pinpointing affected areas.
As a critical supplement to other epidemiological tools and methods, sewage surveillance holds immense promise for improving our understanding of community health and developing solutions that address communities’ specific needs. In their quest to keep their residents safe and healthy, local governments would be well-advised to turn to wastewater epidemiology.