The uncomfortable link between poo and privacy

New York state officials struggled in mid-summer to shed light on a polio outbreak. They used a proven approach that has gained new attention in monitoring the spread of COVID-19: the collection and analysis of water samples containing human waste from sewage systems.

Wastewater monitoring has a long history in the fight against infectious diseases. More recently, it has been implemented in at least eight states in the track an outbreak of monkeypox. But it comes with its own risks, including the potential to infringe on privacy and to be used for purposes other than public health, such as in law enforcement – ​​uses which, if pushed too far far, could further erode Americans’ trust in government.

There is no denying that the value of wastewater monitoring as a public health tool is undeniable. Last July, doctors in Rockland County, New York, diagnosed a 20-year-old man with the first case of polio in the United States in nearly a decade. Public health officials wanted to get ahead of the disease so they could roll out vaccinations. In the past of the disease, by the time they saw a case, it was too late to protect the patient and, probably, too late to prevent the spread of poliomyelitis. So state officials went looking for signs of the disease in nearby communities — in the sewage.


They discovered that polio was not a problem they could simply eliminate. In addition to Rockland County, sewage tests revealed the disease in at least two other counties as well as New York, prompting Governor Kathy Hochul to declare a public health emergency and take steps to scale up vaccinations.

Push back against COVID-19

During the COVID-19 pandemic, a major and persistent problem had been tracking the spread of the disease and its variants. Counties were the building blocks of the data system, but data collection was often weak, especially in states where top officials made COVID-19 a political corner. Additionally, across the country, not all counties have collected COVID-19 data in the same way. It was difficult to fight the disease in the dark. Researchers at the University of California, San Diego have found they can detect RNA indicative of COVID-19 in campus wastewater. They collected the data and published it on a digital dashboard. On a summer afternoon in 2020, the research team detected one positive case. Over the weekend, they tested more than 650 people living and working in the dormitory and helped stop a COVID-19 outbreak in its tracks.

The success of the UC San Diego experiment led the CDC to create a new National Wastewater Monitoring System. The system funded the development of wastewater treatment systems across the country, covering health services in over 40 jurisdictions which serve more than 16% of the country’s population. The CDC has estimated that at least 80% of the population could eventually be served by monitoring the poop and urine flowing down the nation’s sewers. Other scholars have taken up the theme; the University of California, Merced, created a dashboardaptly called COVIDPoops19, which now tracks wastewater monitoring efforts in 70 countries.

Newsha Ghaeli, a former MIT student, holds the prototype of a device used in sewage systems to track and analyze a wide range of pathogens. Ghaeli then launched wastewater testing startup Biobot Analytics. (David Kidd/Governor)

COVID-19, monkeypox and poliomyelitis show what wastewater monitoring can accomplish. But as Vladimir Putin’s strange drive on the road shows, it can also raise big questions. Putin is apparently so concerned about what he might leave behind – and what it might tell adversaries about his health – that his bodyguards collect his excrement as he travels, put it in separate bundles, pack it in a special briefcase, and bring it home.

Presumably, few Americans would go so far as to create a personal poop patrol. But wastewater monitoring raises big privacy issues that go far beyond what’s behind a closed door. It can, as we have seen, detect COVID-19, monkeypox and poliomyelitis. But it can also detect pesticides and pharmaceuticals, including illegal ones. The concern is that this could, in turn, draw police attention to individual neighborhoods.

Of course, sewage monitoring cannot identify anyone’s individual waste (unless the system is as elaborate as Putin’s). But the system can identify problems in relatively small neighborhoods. The same science that allowed UC San Diego scientists to zero in on a particular dormitory would also allow local police to zero in on a few blocks where sewers suggest cocaine use or fentanyl manufacture.

The issue of gunshot detection

Sophisticated technology identifying individual neighborhoods has already eroded trust. While the Inspector General of Chicago found that police responses to the ShotSpotter gunshot detection system “rarely yield evidence of a gun crime, rarely result in investigative stops, and even less frequently lead to the recovery of related evidence to a firearms felony during an investigative arraignment,” Judge MacArthur said. Center documented that Chicago’s system had been “massively rolled out in black and Latino neighborhoods”, exacerbating “resident distrust and fear”.

Wastewater monitoring risks the same problems, especially as the technique becomes more sophisticated and allows investigators to focus on particular communities. It is possible to imagine, indeed, days not too distant that would allow investigators to obtain a search warrant to check the waste from a single building that they find suspicious.

At this point, the potential for using wastewater monitoring outside the realm of public health might only be theoretical – at least in this country. Yet its value for disease monitoring and control is so enormous that its use for this purpose is likely to continue to grow. With a surveillance system that uses a constant (indeed, unavoidable) supply of raw materials and can identify neighborhoods where diseases are emerging before many cases appear, it is easy to imagine that water testing waste becomes a first-line tool in public health – what is already called “wastewater epidemiology.”

But the risks are real. For a long time in American federalism, the adage has been that trust in government is greater the closer government is to the people. Wastewater monitoring is all the more useful as scientists get closer to people. It puts a whole new spin on the “eeewww” reaction that the mere mention of the government evokes in so many Americans these days, pushing their concerns to those little rooms where people value their privacy most. This may not be the prescription for building confidence.


GoverningThe opinion columns of reflect the opinions of their authors and not necessarily those of Governingeditors or management.

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