Sewers don’t lie. People may be less than forthright about what they put into their bodies, especially if that includes illicit drugs, but a chemical analysis of what comes out of their bodies removes all mystery. According to drug and addiction researchers, analysing wastewater for remnants of illicit substances provides the only truly objective indicator of drug use patterns in a community.
“Whatever you think about drugs, people need to have objective data so they can at least have an informed discussion,” says Caleb Banta-Green, a research scientist at the University of Washington’s Alcohol and Drug Abuse Institute in Seattle.
In a study of the wastewater in 96 municipalities in Oregon, Banta-Green and colleagues collected data on the presence of drugs such as cocaine and methamphetamine (Addiction 2009;104:1874-80). They found that cocaine use was much higher in cities, whereas methamphetamine was popular in all areas. Wastewater testing was a promising drug surveillance tool, one that could help communities better combat their drug problems, the paper concluded. “Data on drug index loads are of value for planning local drug prevention, intervention and treatment efforts at a much smaller geographic level and with better timeliness than was possible previously.”
Traditionally, the amount of illegal drugs consumed at the community level is estimated from sources such as surveys, police data and information from emergency rooms and morgues. Often, however, this information is rife with bias and tells only part of the story.
Surveys miss certain segments of the population, such as inmates, and are prone to self-report bias because of the stigma of illegal drug use. There is detection bias in police data because drugs such as crack cocaine, often used on the street, result in more arrests than drugs such as powder cocaine, which is more commonly found at private parties. As for hospital data, a death attributed to a traffic accident might actually be a death due to the drug abuse that led to the accident.