1) Marijuana is a psychoactive drug that adversely affects the brain. For anyone under age 25 it can cause permanent, psychical changes that can lead to loss of IQ by as much as 8 points, but as well can lead to mental illness and psychotic breaks in vulnerable individuals that have and are leading to mass murders and suicides. For anyone over 25, it still adversely affects memory, health, cognition and work performance.
2) Marijuana is a fat soluble, fat loving substance that stays in the body and brain for roughly one month, longer than any other drug. The brain is the fattiest organ in the body so the THC (psychoactive ingredient) accumulates there, compounding with each additional joint or ingestion of cannabis. So it doesn’t matter whether marijuana is consumed on the job or not. Impairment lasts much longer, even from occasional use in the evenings or weekends.
3) Studies by the post office indicate that marijuana users have more sick days and cause more accidents, 82% of which harm others. Other studies show that the adverse impacts to memory, motivation and cognition adversely affects work performance.
4) Addicts quite often can’t feed their habit without turning to crime, so they resort to stealing
Bottom line? Most pot smokers are a danger to themselves and others, and not capable at working at optimum levels. Employers, tasked with earning a profit for themselves and/or investors, have a right and obligation to maintain a safe and drug free work place.
Until and if the federal government decides marijuana is safe and effective as a medicine, anyone who chooses to be employed should use legal medicines. If they insist on THC, they can get a prescription for Marinol, a legal drug in pill form.