It seems the launching of the drug testing campaign in America's workplace has been based on anti-drug hysteria and a motive for profit, and not on a careful analysis of the relationship between illicit drug use and workplace safety and productivity. A major flaw in the use of drug detecting tests such as urinalysis is they cannot show whether an individual who has tested positive was actually impaired while at the workplace. Rather, they detect the presence of non-psychoactive drug metabolites, which may linger in one's system for days, or even weeks. This is in marked contrast to the breathalyzer and blood tests for alcohol, which detect impairment only at the time of the test. Of concern is the urinalysis test's particular sensitivity to marijuana.
Nobody wants an arborist on the job who is high on pot.
But there are 20 to 30 million marijuana users in this country, the majority of whom confine their use of the drug outside of the work place. It is much more likely that the lingering metabolites of marijuana will be detected in one's system than metabolites of harder drugs such as heroine or cocaine, which wash out of the system in two or three days. As a truck driver and former full-time arborist who has discussed the situation with many of my coworkers, I believe the answer is yes. It is obvious that the risk of testing positive for amphetamines and cocaine is low compared with marijuana. A pair of studies have suggested that the recent decline in marijuana use has led to an increase in drug-abuse emergencies and auto fatalities owing to alcohol and other drugs.