US city considers testing entire city for drugs

A city in the US is considering testing all residents for marijuana, even though the drug is now legal.

After marijuana was legalised in the city of Spokane in Washington State, city leaders wanted to understand more about its use within the population and answer questions such as: How many people are using marijuana? When is it used? City officials need to understand drug habits in the city to better support their people and create better policies.

However, the prospect of testing an entire city with a population of 210,000 for marijuana use is out of the question.

There have been telephone surveys in the city, but officials are not convinced that people are honest in such surveys. Even though marijuana is now legal, it is thought that many people will still say that they do not use marijuana on a regular basis to a telephone interviewer.

This is largely because while marijuana is legal in the state, some companies have a zero tolerance for drug use. Many people will simply lie to ensure that they are not accidentally admitting their use of drugs to an employer. Hiding a drug habit is still one of the most common lies found on job applications.

Testing the waters

Alison Holcomb is the primary author of Washington State’s recreational marijuana law, and proposed that the city’s wastewater be tested for the presence of marijuana. City council member Jon Snyder explained: “We don’t have really good data on usage and perceptions of harm.”

Since legalisation, the traditional methods of drug testing are no longer possible. Police cannot routinely test individuals for drug use, and this means that the city no longer has any clear picture of how many people are using marijuana.

Two studies were developed to look for traces of drugs in wastewater, and were both shown to be successful.

Caleb Banta-Green from the Alcohol and Drug Abuse Institute at University of Washington said: “In some ways, I think my most surprising finding is that it works. When I first heard about it I was sceptical. I thought, ‘How is this going to be sensitive enough?’”

Mass spectrometer

Testing was carried out using a mass spectrometer that measures tiny quantities of drug metabolites in sewage – even if only a few parts per billion are present, the apparatus will detect them.

To test the theory, Daniel Burgard, a researcher at the University of Puget Sound in Tacoma, Washington, tested wastewater running downstream from a college campus. He tested for the presence of Ritalin and Adderall, which are two metabolites of amphetamines. If they are found in the sewerage, it means that at least one student has taken the drug recently.

Burgard’s results showed that “amphetamine levels go through the roof during finals.” It is not known if students are using it as a party drug or to help stay alert and focus on their work.

Sewage testing has already been carried out in European cities. In 2005, Italian researchers reported that they detected up to five kilograms of cocaine every day in the Po River near Milan.

Although this form of drug testing can never provide an accurate figure for drug usage, it can be compared to data taken by other means and help to report trends in usage. It can also help to determine the effectiveness of drug awareness campaigns.