By James Orr and Nina Goswami
To early morning joggers, the sight of a man drawing buckets of water from a boat midstream in the River Thames may have seemed a little unusual.
On board were a team of three scientists, experts in their field, who were for the first time attempting to test for the presence of cocaine in Britain’s most famous river.
Their series of sophisticated calculations based on data obtained from Thames water aimed to uncover the true extent of cocaine abuse in the UK.
The results from the Sunday Telegraph investigation make shocking reading. The research suggests that levels of cocaine use in London are 15 times higher than official estimates.
Clinical toxicologist Prof John Henry warned yesterday: “Anyone who persists with using cocaine is inevitably causing damage to their health.
“Because of the long-term complications of cocaine use, we are looking at a healthcare timebomb. It will creep up on us just as surely as tobacco and alcohol have done.”
Unlike in the US, where experts claim cocaine use has peaked, the culture of taking the Class A drug in Britain is continuing to grow.
Chemical compounds of the narcotic do not break down easily, making it relatively simple to test for. Traces of the white powder are likely to pass through the user and into sewerage networks. But even when the sewage has been processed and the water returned to the rivers, significant evidence of the drug still remains.
Navigating their way along the Thames aboard the aptly named Watchdog, scientists from Milan’s Mario Negri Institute for Pharmacological Research took water samples from a variety of sites.
Dr Chiara Chiabrando, Dr Sara Castiglioni and Dr Ettore Zuccato had previously found the equivalent of 4kg of cocaine per day flowing down the River Po in northern Italy after testing for cocaine and its metabolic by-product, benzoylecgonine.
In Britain, the team began their research in south-west London, taking samples downstream of Mogden sewage-treatment plant near Twickenham. The plant serves 1.8 million Londoners, processing raw sewage from nearby homes.
The scientists then travelled down the river towards Europe’s biggest sewage plant, at Beckton, which serves about 3.7 million people in east London.
More tests were done downstream of the plant at Tilbury and then sewage samples running into the treatment sites, known as influent samples, were collected at both Beckton and Mogden. Back in Italy, the team began to analyse the data.
Annual Government crime figures taken from the 2003/04 British Crime Survey estimate that 344,000 people take cocaine in England and Wales each month. Extrapolation from this figure suggested that Londoners were taking 2,397 doses of 100mg per day, the equivalent of 9,588 lines at 25mg per line.
But the sewage samples obtained from Mogden and Beckton plants indicated that the actual figures for cocaine abuse were far higher. Tests found that 37,638 doses of cocaine, or 150,552 lines, are consumed in London every day, nearly 16 times more than the government figure of 2,397 doses.
Astonishingly, scientists even found that water from the Thames already treated by sewage works still held an estimated concentration of 20,000 doses, or 80,000 lines, of cocaine.
This still equates to more than eight times the quantity of cocaine the Government believes to be consumed in London per day.
Overall the team found that out of the 5.5 million Londoners who were served by the two plants, there were an estimated 38 users per 1,000 per day.
Official figures suggest nearly four million people in England and Wales have tried Class A drugs – including heroin, cocaine, ecstasy, LSD and magic mushrooms – at least once.
Their numbers have increased, mainly due to a surge in cocaine use up until 2000, despite the -Government’s now-abandoned target of cutting figures by 25 per cent.
Cannabis stands as the most commonly used drug, followed by cocaine, which is now more popular than ecstasy.
Last month Prof Henry revealed an astonishing 10 per cent of patients treated at St Mary’s Hospital, west London, for suspected heart attacks and chest pains had recently taken cocaine.
At weekends, he found, that figure rises to almost 50 per cent among the under-40s.
He warned yesterday: “Cocaine causes massive stresses on blood vessels and when those stresses are repeated time and again you end up with coronary heart disease.
“The risk factor in suffering from coronary artery disease is more certain than smoking, high cholesterol or blood pressure.”
A spokesman for the drug awareness group -DrugScope added that plunging cocaine prices over the past decade had contributed to its popularity. Petra Maxwell said: “The price of cocaine has seen a drop, particularly in the South-East and London, where a gramme which cost £70 seven years ago can now be bought for £40.
“While the British Crime Survey is widely regarded as the best indication we have of drug use in England and Wales it is flawed as it is less likely to capture the most problematic users.”
Dr Chiabrando said: “The concentration levels of cocaine found in the Thames were similar to that in the Po.”
After the academics highlighted the horrifying levels of cocaine consumption in northern Italy, experts were forced to re-evaluate crucial implications for health and crime. A spokeswoman from the Home Office insisted: “Tackling drugs remains one of the Government’s highest priorities and is backed with record investment.
“The strategy focuses on the most dangerous drugs, the most damaged communities, on problematic drug users and the most vulnerable young people.”