Legalizing marijuana would also entail modification of current drug testing for FAA and DOT employees...and any other safety sensitive field. Right now, THC can be detected in a persons system (depending on weight, amount ingested, frequency of use, and time between use and testing) for up to a month, so that would have to be adjusted to detect use only for the past 8 hours or so, same as alcohol (8 hours from bottle to stick)...
