A project on young people's use of cannabis shows that 30 per cent of the 500 pupils at Castleknock Community College, Carpenterstown, Co Dublin, had taken it. The study, done by Nicole Daly, Aimee Farrelly and Eimear O'Neill, also showed that of those pupils, 40 per cent had been introduced to cannabis by friends or peers, 33 per cent by strangers and 27 per cent by relatives.