A growing number of students as young as 12 are experimenting with alcohol and experts warn of a close link between drinking, teenage sex and drug use. A survey of 95,788 secondary students conducted by the Chinese University in 2000 found that 65.1 per cent of children aged 12 had tried alcohol, compared with 49.6 per cent in 1996. Among 13-year-olds, 72.6 per cent had drunk at least once - a 10.5 percentage point increase from four years ago. In the 17-year-old age group, 87.5 per cent admitted they had tried alcohol - up 4.8 percentage points from 82.7 per cent in 1996 - despite the law prohibiting the sale of alcohol to those under 18. By comparison, about 50.5 per cent of 13-year-olds and 79.7 per cent of 17-year-olds in the United States admitted they had taken a drink last year. The 2000 Survey of Drug Use among Students was commissioned by the Narcotics Division of the Security Bureau. The students polled represented 16 per cent of all those enrolled in local secondary schools, 69 per cent of those at international schools and 62 per cent of those at institutes of vocational education. The survey's report gives no breakdown according to the background of the students. Joseph Lau Tak-fai from the Chinese University's Centre for Clinical Trials and Epidemiological Research, who carried out the survey, told the South China Morning Post early findings showed a close link between alcohol and behavioural problems such as teenage sex and drugs. Thirty-seven per cent of young men and nearly 20 per cent of teenage girls said they had had sex after taking drugs. Dr Lau said the figures showed drinking could double teenagers' chances of turning to drugs. He explained young people could easily have their judgment impaired by alcohol. The findings also show only 20.3 per cent of students were completely free from any of the four main vices - alcohol, tobacco, heroin and psychotropic substances - a fall from 27.2 per cent in 1996. Dr Lau said the problem of teenage drinking had been overshadowed by drug abuse and smoking, so it did not receive enough attention in the community. There is a general drop in the number of young smokers - from 26.8 per cent in 1992, 23.7 per cent in 1996 to 22.2 per cent in 2000. But the report shows a more than sixfold increase of heroin use among students in eight years - from 0.4 per cent of students in 1992, to 2.1 per cent in 1996 and 2.6 per cent in 2000. There is also a rise in the use of psychotropic - mind-altering - substances among young people, from 3.1 per cent in 1992 to 4.1 per cent in 2000. Dr Lau's colleague, anatomy professor Alfreda Stadlin, also an expert on alcoholism and drug abuse, was concerned that unless the Government took action the number of young drinkers would continue to grow. Dr Stadlin also agreed the problem of drinking was easily ignored as there was always a misconception that it was not easily addictive. 'There are medical findings showing the younger people take up alcohol, the easier they will be addicted to it when they grow older,' Dr Stadlin said. Police yesterday said they conducted regular checks at entertainment premises, particularly those in Yau Ma Tei, Tsim Sha Tsui and Mongkok in a bid to crack down on the sale of alcohol to minors. 'The force is committed to crime prevention in these places . . . Anyone who is found in breach of the law will be arrested and prosecuted accordingly,' a police statement said.