Fear this: The follicles on your head can reveal the folly of your ways, especially if you are into drugs.
Long before the Central Narcotics Bureau (CNB) began using hair-sample analysis to detect drug use, such tests were already striking fear in students from international schools in Singapore.
The CNB has been using hair samples on ex-drug abusers serving out their compulsory two-year supervision order since May.
But, say insiders, international schools here have long been carrying out such tests on its students and sending the samples overseas to detect drug abuse.
William (not his real name), a student at an international school here, told The New Paper: "The drug tests are very random, you never know when its coming.
"In most cases, you are just pulled out of your classroom and tested under supervision."
Youth drug abusers are a growing concern, although they account for the smallest percentage of arrests, according to CNB statistics.
For the first half of this year, 83 of the 1,790 drug abusers arrested were below the age of 20.
Less than 10 per cent of those arrested below that age are non-locals, said a CNB spokesman.
It is not known when international schools here began using such tests but The New Paper reported in 2004 that schools such as United World College of South East Asia (UWCSEA), the Singapore American School (SAS) and the Tanglin Trust School conducted such tests.
UWC, for example, said in the report that it conducts both urine and hair tests.
Urine samples are sent to Australia and the hair samples are sent to the US.
Random drug testing, which includes sampling strands of hair, is a powerful reason to say no to drugs, said William, a 17-year-old Briton.
SUSPENSION IF CAUGHT
Students face suspension, compulsory counselling and monthly re-testing if they test positive for drugs. If they test positive a second time, they will be expelled.
At his school, said William, students are usually pulled out of their classes at random and accompanied for a urine test.
If they are unable to give a sample, they are made to wait until they are able to try again.
A few strands of hair are also taken as samples, he added.
Yet, said William, some students continue to gamble with their future.
"It's not prevalent, but I still hear stories of kids experimenting with weed (slang for cannabis) at parties."
These parties are usually held at homes, mostly private properties near Bukit Timah. They are usually kept to about 10 students or fewer, who are there on an invitation-only basis.
"In school, we are reminded of the strict laws against drug use here.
"But even though these tests are random, some still do it for the thrill and the belief that they would never get caught," said William.
"Some try it for fun because their friends do it.
"Many also believe that weed is not addictive, unlike heroin or other harder drugs which they stay clear of," he said.
Worryingly, cannabis is seen as a soft drug by these students, despite Singapore's tough penalties on the use of the drug.
Furthermore, they also believe cannabis - which can cost up to $50 for a small bag - is harder to detect, unlike methamphetamine, or Ice, another drug that is popular among young people here.
But the penalty for cannabis is heavy: A maximum sentence of 10 years in jail and a $20,000 fine. Dealing with, for example, 500g of pure cannabis is a capital offence.
CNB has said that cannabis was the third most commonly abused drug behind heroin and methamphetamine.
The number of new cannabis abusers arrested went up from 38 in the first half of 2012, to 51 in the same period this year.
None of the international schools contacted would comment on their drug tests.
TESTS DONE OVERSEAS
One institution, the Australian International School, said it does not "discuss our policies in this area with the media".
According to previous newspaper reports, most international schools here have the drug tests done overseas to keep results confidential.
Samples sent to local laboratories must report positive drug test results to the authorities.
Lawyer Shashi Nathan, who has represented expats and locals in drug-related cases, said: "If any of the students are tested here, then the drug laws will apply to them.
"This maybe the reason why such tests are conducted overseas."
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