370 adults taking part in Basel’s “Weed Care” scheme – a 2.5-year recreational pot smoking study. Its aim is to examine the impact of regulated cannabis supply on the health and consumption behaviour of users with a view to possible changes to the Swiss law. Basel was the first of seven Swiss cities to launch scientific studies this year. The results - especially on health risks, smoking habits and problematic consumption - will be closely scrutinised in the coming years. The pilot projects have public support yet remain contentious. Could Switzerland’s cautious step-by-step scientific approach offer a new way forward for countries considering whether to allow recreational cannabis? (See also: Switzerland’s pioneering legal cannabis experiment: Basel’s story)