Our sewage reveals a lot more about us than what we ate over the weekend. Scientists at Murray State University in Kentucky have been studying sewer water for the past few years, hoping to pinpoint the level of drug use within local communities. Their latest research, presented this week at the American Chemical Society’s annual meeting, suggests Americans are using more drugs than official estimates tell us, and that drug use goes way up when the holidays roll around.
The researchers tested samples from sewage treatment centers in two nearby towns in Kentucky during two time periods in 2017: The days surrounding July 4 (U.S. Independence Day) and Monday August 21, when a total solar eclipse stretched across North America. On July 4, the team found, there was a much higher concentration of residue from drugs such as amphetamine, methamphetamine, cocaine, and morphine in the water of both towns than there was on either July 3 or July 5; similarly, consumption was higher on the eclipse day than on other “normal” Mondays.
Other research has found that people use drugs more on holidays and special occasions, but these findings (which, it should be noted, are preliminary and not yet published) are meant to be another validation of the team’s unique, reportedly more efficient technique for measuring drug use, known as sewage epidemiology.
Bikram Subedi, the senior researcher behind the current study, had earlier used this technique to look at illicit drug use in communities nearby Albany, New York; he’s also studied how often legal pharmaceuticals end up in wastewater, where they can potentially damage the environment or wildlife.
Researchers elsewhere, predominantly in Europe and Asia, have also used this technique to indirectly measure drug use. A 2013 wastewater study out of Australia, for instance, found that drug use rose during the holidays, especially in cities. And wastewater testing is even being reportedly used by law enforcement in China to track drug operations.
“The conventional approach to assess community drug usage in the U.S. takes months or years,” said Subedi in a statement. The team’s analysis, meanwhile, can identify drugs and the chemicals they metabolize into within hours or days. More traditional measurements, which can involve surveys, toxicology or medical reports, and crime statistics, can also be much costlier to run.
In addition to being a speedier way to track how often and when people are taking drugs, the findings might also indicate that Americans are getting high even more than expected. According to the team’s calculations, the percentage of people using amphetamine and methamphetamine in their sample was two to four times greater than federal government estimates for use of those drugs among the general population. According to the Substance Abuse and Mental Health Services Administration, about 1.5 million Americans, or 0.6 percent of the country, use these stimulants.
However, Kentucky is one of the states that’s been most battered by the ongoing drug crisis, with an opioid overdose death rate that was double the national rate in 2016. And the amount of meth seized by law enforcement officials there has reportedly increased in the past few years as well. So it’s possible these findings are only highlighting the state’s relatively high level of drug use, rather than showing us something new about Americans’ drug habits.
Subedi and his team next plan to use their method to better isolate pockets of drug use within a local community by testing sewage before it reaches a treatment plant; they also hope to try mapping out drug use on a national level.