People are allowed to have a maximum of 30 grams of dried cannabis in public at any time or equivalent to five grams of fresh cannabis, 15 grams of edible product, 70 grams of liquid product, one cannabis plant seed or a quarter of a gram of concentrates. February 20, 2020 (Toronto) ndash; While rates of drinking, cigarette smoking and overall drug use continue a long-term downward trend among Ontario students in grades 7 through 12, the use of e-cigarettes (vaping) has more than doubled since 2017, according to data released today by the Centre for Addiction and Mental Health (CAMH). The numbers are from CAMHrsquo;s Ontario Student Drug hop over to this web-site Use and Health Survey (OSDUHS), an Ontario-wide survey of 14,142 studentsmdash;Canadarsquo;s longest-running systematic study of drug use among youth, and one of the longest-running in the world.