The Armed Forces, as well as many civilian factories, will boot you out if you smoke marijuana; even if you smoke it 30 days before testing and while off duty. These tests are done at random and often do not include liquor, tranquilizer or other speed/downer type drugs. However, according to OSHA and insurance actuarial findings, plus the AFL-ClO, it is alcohol (!) that is involved in 90-95% of drug related factory accidents.
In fact, numerous U.S. Army tests of the effects of cannabis on soldiers (through the 1950s and ‘60s) at Edgewood Arsenal, Maryland, and elsewhere, show no loss of motivation or performance after two years of heavy (military sponsored) smoking of marijuana.
This study was repeated six more times by the military and dozens of times by universities with the same or similar results. (Also, British Indian Hemp Report,
Panama/Siler study; Jamaican study, et al.)
South African gold and diamond mines allowed and even encouraged blacks to use cannabis/dagga which enabled them to work harder.