Analysis (4) analyse (3) Drugs (3) puits (2) temps (durée) (2) information (2) gaz (2) abords (agglomération) (2) Drug use (2) Control (2) Surveys (2) Statistics (2) Programs (2) Needle exchange programs (2) Time (2) Syringes (2) Surveys (2) Substance abuse (2) Questionnaires (2) Medicine (2) Human beings (2) Heroin (2) Gas (2) Drug utilization (2) Drug abuse (2) Cocaine (2) Harm reduction (2) Statistics (2) Substance use (2) Medicine (2)