Urine, blood and even saliva can show that someone was exposed to THC, but they cannot reliably establish when it was used or whether the person was impaired at a particular point several hours earlier, according to Marcotte.
Saliva is more closely linked to recent use, but can still detect THC many hours - and potentially a day or two - after consumption, he says.
Urine, blood and even saliva can show that someone was exposed to THC, but they cannot reliably establish when it was used or whether the person was impaired at a particular point several hours earlier, according to Marcotte. Saliva is more closely linked to recent use, but can still detect THC many hours - and potentially a day or two - after consumption, he says.
