BOSTON--It's like getting an entire city to pee into a cup. At the annual meeting of the American Chemical Society, scientists reported here yesterday a better way to measure a community's drug use by testing its wastewater.
Estimating a city's drug use has been notoriously difficult and unreliable. Epidemiologists usually conduct personal surveys or track hospital emergency room visits and calls to poison-control centers. But surveys typically underreport drug use, as many people are reluctant to admit breaking the law. What's more, monitoring programs tend to overemphasize the use of the most dangerous drugs, such as heroin. In recent years, chemists worldwide have shown that it's possible to detect both legal and illicit drugs in wastewater and rivers. But the standard way of doing so requires a slow and expensive technique to concentrate samples before detailed analysis.
To speed things up, a team led by Jennifer Field, a chemist at Oregon State University in Corvallis, and her colleagues did away with the concentration step. To compensate, they increased the throughput of the next step in the process 100-fold. This step, known as liquid chromatography, isolates the exact compounds of interest, which are then sent to a mass spectrometer that confirms their chemical identity. Comparisons of the high-speed technique with the conventional version showed that both picked up equivalent levels of drugs. The researchers then studied wastewater samples from 10 cities throughout the United States, testing for 14 illicit, prescription, and nonprescription drugs including heroine, cocaine, methamphetamine, and oxycodone.
A detailed preliminary analysis from six cities showed that all tested positive for cocaine, and five of six for methamphetamine. When the researchers tracked one city over a month, they found that use of "recreational" illicit drugs such as cocaine spiked on weekends, whereas other drugs such as methamphetamine showed a consistent presence in wastewater. Field says her team did not identify the cities surveyed because they are concerned that doing so would discourage other municipalities from cooperating with her research team in the future.
The new work "is a very good start" to getting an accurate and widespread picture of communitywide drug use, says Niels Jonkers, a chemist with the Institute for Inland Water Management and Waste Water Treatment in Lelystad, the Netherlands. One plus, Jonkers and others point out, is that the new high-speed approach was done by modifying commercially available equipment, which may make it easier for other labs to adopt. If so, Fields says she hopes that the new technique will give cities a better handle on just what kind of drug use they face and thereby make them better able to help their citizens.