Drug and alcohol abuse costs U.S. business as much as $140 billion a year in lost productivity, accidents, healthcare costs and absenteeism. People abusing drugs and alcohol on the job have three to four times the number of accidents as those who don't.
the problem with using that number to argue to keep drugs illegal is that the situation would not be the same after legalization. the same amount of drug use might not account for the same proportion of cost. although the page you linked to doesnt source itself, it matches the $140b figure the Lewin Group came up with in The Economic Costs of Drug Abuse in the United States. let's look at each cost
healthcare costs: in terms of overdose, almost all are from mixing drugs, which usually is because people are unaware of which drugs are dangerous to mix with which
other overdoses are due to unknown dose, another consequence of getting drugs from the black market
in terms of health/disease, unknown dose and impurities contribute greatly to this
two of the highest costs in the healthcare figure are drug exposed infants and the highest by far is HIV/AIDS. in an illegal environment, both of these are horribly exacerbated. pregnant mothers may be afraid to get treatment letting their infants' problems grow wrose without getting the help needed to quit. and of course HIV/AIDs spreads with needle sharing
healthcare costs would probably decrease. even if they did, though, healthcare costs only make up 9% of that 140$bil figure
productivity costs: this figure accounts for 69% of that $140b. it includes:
premature death - would decrease beacuse overdoses would be far less common
drug abuse related illness - would decrease because drugs would be far less hazardous to use
hospitalization - would decrease for the same reason
productivity loss from victims of crime - would decrease because with a greatly reduced black market, there would be greatly reduced homicide and with cheaper drugs there would be no need to resort to crime to pay for habits
incarceration - this is an easy one. no productivity loss due to this because no one would be in jail for drugs. this is the biggest cost in this category as well
crime careers - with less people in the black market, less money would be lost to the black market. this would go down
now lets look at
other costs which accounts for 22% of the $140b
nearly all of this figure is under Criminal Justice System and otehr Public Costs, which wouldnt exist once drugs are legal
the smallest figure is from property damage for victims of crime, which would decrease, and the second smallest figure is private legal defense, which wouldnt need to exist at all
if you want to argue numbers, at least know what your numbers mean. in terms of med costs, govt costs, economy, and civil liberty, drug use makes absolutely no sense