Out of all the drug testing methods employed by courts and square workplaces across the nation -- hair testing has the daunting reputation of being the most thorough/menacing.
While urine testing is known to detect THC from a few days to more than a month (for everyday smokers), hair testings claims to be able to detect marijuana use for months, even years after going cold turkey. There have been some serious objections to hair testing, but it is still being used in child custody cases, professional screenings, and other high-stakes situations that can make or break a person's entire life. Obviously, it'd be much cooler if it wasn't.
But now, a group of German scientists are striving to change the general consensus on hair testing, as they claim a positive hair test can be triggered by a hair's external exposure to second-hand smoke, or even by someone with cannabis "dust" on their hands, touching the hair in question. This is the problem: you could test positive on a hair test (and face the serious implications that come with it) without ever actually partaking, personally.