Concentration of drug in city’s sewers may have fallen by almost a third over three years

The concentration of cocaine in London’s sewers may have fallen by almost a third over three years, new research has suggested. Wastewater tests taken over a week in April 2019, published by the EU’s drugs agency on Thursday, appeared to indicate a drop in consumption in the capital.

The study’s lead researcher, Dr Leon Barron, from King’s College London, said the cocaine market in the city may have begun to be saturated. However, he noted tests at other times of the year could have delivered different results and urged caution in extrapolating his findings.

“More regular monitoring in London and ideally across several locations is required to build up a more accurate national picture before we can conclude that cocaine use has actually dropped in the UK,” Barron said.

“It remains a major problem in London and wastewater analysis provides a unique way to help understand illicit drug use trends on a population level in near-real time.”

But while cocaine is far more prevalent in Antwerp and Amsterdam, according to the European monitoring centre for drugs and drug addiction data, it remains widespread in London.

In the city’s wastewater per 1,000 people, there was 619mg of benzoylecgonine, the compound produced when the body breaks down cocaine, compared with 895mg in 2016 – a 31% fall. The research was not undertaken in 2017 and 2018.

Last month, a landmark independent review commissioned by the Home Office reported that crack use in London had reduced substantially over the decade while powder cocaine use had fallen since 2014.

Although the stimulant is used widely across socioeconomic groups, prominent figures including the Met police commissioner, Cressida Dick, the mayor of London, Sadiq Khan, and David Gauke, when he was justice secretary, have denounced “hypocritical” middle-class cocaine users for helping fuel drug-related violence.

Recent nationwide increases in class A drug use, which is at record levels, are believed to have been primarily driven by powder cocaine and ecstasy use among 16- to 24-year-olds.

However, many young people in London are known to be increasingly using other substances, particularly psychedelics.

Seizures of cocaine in England and Wales – much of which would have been destined for the capital – tripled last year to almost 10,000kg, although the amount entering the UK undetected could be several factors larger.

Organised crime sources said criminal groups in London had raised wholesale prices significantly over the last 18 months, blaming the threat of Brexit and greater checks at borders, along with the increased seizures.

The apparent fall in the concentration of cocaine in the wastewater may also be down to reductions in its purity, after sustained increases in recent years.

Lawrence Gibbons, the head of drug threat at the National Crime Agency, said: “Drug trafficking is a global threat and its corrosive effects can be felt in the UK, causing violence and exploitation at every stage. We estimate that demand for all common drug types, including cocaine, remains steady.”

Steve Rolles, a senior policy analyst at the Transform Drug Policy Foundation, said any fall in cocaine use in London would be welcome, but stressed that national survey data for the UK showed increased usage amid rising deaths.

“Wastewater analysis doesn’t distinguish between powder and crack cocaine, making it especially difficult to identify what is driving any change,” he said. “The use of cocaine and other stimulants is rising across the whole of Europe, which clearly shows a failure of the current enforcement approach.”

The study also detected 58mg per 1,000 people of methamphetamine, also known as crystal meth, in London last year, while Prague in the Czech Republic recorded the most, at 727mg.

The amount of MDMA, which is known to be more commonly used in most of Europe than crystal meth, found in London’s wastewater fell from 55mg in 2015, the last year for which there was data, to 50mg in 2019. Across Europe, the highest concentration was recorded in Utrecht, at 129mg.