Last November, the fire chief of Cary, North Carolina, told a group of town supervisors that his department had responded to five drug overdoses that week, three of them fatal.
“That started a conversation along the lines of ‘How could this be happening in Cary?,’” recounts Mike Bajorek, the deputy town manager, in an interview with The Opioid Research Institute. Located in the state’s Research Triangle, Cary is an affluent community of about 160,000, where more than half the residents hold at least a bachelor’s degree and the median income runs around $95,000.
Amid a national opioid epidemic, such conversations are commonplace in American communities. But what Cary’s leaders did next is unique. They put together a proposal and then, in February, won a $100,000 Bloomberg Philanthropies Mayor’s Challenge Grant to test a new data-mining tool to help them analyze and monitor their community’s opioid consumption. In doing so they launched what appears to be the nation’s first, systematic wastewater epidemiology program—also known as hotspotting.
Hotspotting means analyzing sewage for traces of legal or illegal drugs that people have excreted. When we consume certain drugs, a percentage of what we ingest will survive unaltered in our urine. In other instances, the drug will be broken down into telltale, simpler substances, known as metabolites. In either case, the quantity of the substance we originally consumed can be roughly back-calculated.
Wastewater analysis can, therefore, reveal the collective drug habits of communities, providing a more accurate picture than self-reported surveys. It can also alert communities to budding problems in their midst at an earlier stage than grim emergency-room statistics and overdose deaths.
Though the Environmental Protection Agency has long tested sewage and industrial runoff for pollutants that might contaminate soil and waterways, only rarely have American researchers—mainly academics—combed through it seeking clues about drug abuse.
In Europe and Australia, in contrast, the practice is well-established. Earlier this month, for instance, the European Monitoring Centre for Drugs and Drug Addiction published the results of its seventh annual wastewater analysis. It examined sewage—usually just before it entered a treatment plant—in 60 cities across 19 countries, searching for remnants of about a half dozen drugs that are of greatest concern there. Using analytical techniques known as liquid chromatography and tandem mass spectrometry, researchers back-calculated the populace’s use of these substances in “milligrams per thousand people per day.” They determined, for instance, that in 2017 European methamphetamine use was worst in Chemnitz and Erfurt, Germany, while growing alarmingly in Limassol, Cyprus. Cocaine use, on the other hand, was most intense in Zurich and Barcelona, while Amsterdam showed the highest consumption of MDMA (ecstasy).
Similarly, last year the Australian Criminal Intelligence Commission began testing 54 wastewater sites across that country three times a year, effectively monitoring the sewage of 61 percent of the country’s population—about 14 million of its 24 million people. Australian authorities track the use of 14 substances, including heroin, fentanyl, and oxycodone. (Its latest study, published in December, reported that utilization of fentanyl and oxycodone had declined there nationally since August, though they remained at “elevated levels,” particularly in rural areas.)
In Cary, deputy town manager Bajorek reached out to a tech startup called BioBot Analytics for help. BioBot, based in Cambridge, Massachusetts, was formed last fall by two MIT grads, Mariana Matus and Newsha Ghaeli. As its name suggests, BioBot uses robotic equipment that can be lowered into a sewage stream.
“It’s full collection, measurement, and analysis—an all-inclusive service,” says Matus in an interview. “We can give them estimates of consumption of opioids from different areas in their town.”
“Sampling areas will have between 5,000 and 6,000 people,” Cary’s Bajorek said in an email, “and we are looking at up to 10 sampling locations.” Initially, the project will search for the metabolites of a range of opioids, including heroin, oxycodone, and hydrocodone, plus such addiction treatment medications as methadone and buprenorphine.
Jason Williams, a researcher for the Alcohol and Drug Abuse Institute at the University of Washington, says that every type of data has its strengths and weaknesses.
On the plus side, he says, hotspotting gives “a pretty objective measurement of use,” especially compared to surveys.
At the same time, he says, interpretation can be challenging. For instance, he says, 10 percent of the methamphetamine that is taken into the body comes out of it unchanged. So when one detects a quantity of that drug in sewage, it could either represent 100 percent of a quantity flushed down the toilet, or just 10 percent of an amount that was consumed and then later excreted after running through multiple users’ kidneys.
Aleksandria Zgierska, a family physician and the principal investigator for the Madison [Wisconsin] Addiction Recovery Initiative, says in an interview that she’s now assessing whether hotspotting might be a useful tool for her community as well. (Madison is in Wisconsin’s Dane County, where there were 57 opioid overdose deaths in 2015—half the state’s total and double the number the county suffered in 2006.)
“The data we would get has its limitations,” Zgierska acknowledges. “But it’s not the tool, but one of many tools. We use those bits and pieces to see the whole picture.”