It's been a pretty incredible ride for the marijuana movement over the past couple of years. After spending decades as a taboo topic that lawmakers almost always swept under the rug, cannabis has now become a mainstream issue. It's been legalized for adult consumption in Canada, has been given the green light in some medical capacity in more than 40 countries around the world, and has more support in the U.S. than at any point over the past 50 years, according to polling by Gallup.

But there are some folks who might question that lawmakers are moving too far, too fast when it comes to the marijuana industry.

Uh-Oh! Drug use is on the rise in the workplace

This past week, Quest Diagnostics (NYSE: DGX) , a leading diagnostic testing firm, and the company responsible for testing millions of Americans a year in the workplace for illicit substances, released its latest analysis , known as the Drug Testing Index, on workplace drug usage. Having tested more than 10 million urine samples in 2018, Quest found that 4.4% resulted in a positive test, which includes a combination of illicit (i.e., illegal) drugs and prescription medicines. This 4.4% workforce positivity rate is a 14-year high, and it's a 25% increase from the all-time low of 3.5% recorded between 2010 and 2012.

What's driving higher workplace drug use? According to data from Quest Diagnostics, it's not oxycodones, opiates, heroin, or cocaine. For the general population and safety-sensitive workers (e.g., truck or bus drivers, mechanics, pharmacists, nurses, and so on), usage of these illicit and/or prescribed medications has fallen or been relatively steady between 2012 and 2018.

Meanwhile, amphetamine and marijuana use has risen significantly over the same period. Just over 1% of the general population now tests positive for amphetamines, up from just under 1% in 2012. But the biggest increase is seen with the cannabis positivity rate, which has increased by 40% between 2012 and 2018 to 2.8% among the general population. It rose ever so slightly to 0.88% from 0.84% for safety-sensitive workers between 2017 and 2018. Combining the two categories, the national positivity rate in the workforce for urine tests was 2.3% last year.

Should we be blaming cannabis for this increase?

How does that stack up on a state-by-state basis? With the understanding that 2.3% is the national average, here's the workplace positivity rate, according to Quest, in the 10 states to have legalized recreational weed:

• Alaska: 1.6%.
• California: 2.5%.
• Colorado: 3%.
• Maine: 5%.
• Massachusetts: 3.3%.
• Michigan: 3.3%.
• Nevada: 4%.
• Oregon: 4.3%.
• Vermont: 3.7%.
• Washington: 2.4%.

With the exception of Alaska, we do see a considerably higher rate of positive cannabis use in recreationally legalized states. Understand that a handful of states where adult-use pot is illegal were also above the national average, so it's not simply a line in the sand of legalized recreational states versus states that haven't legalized adult-use marijuana. However, there is a pretty consistent correlation that broader legalization has led to higher drug positivity rates, with many of the illicit states that are above the national average being adjacent to a fully legalized state.

Just as concerning is that positivity following an accident has been increasing substantially. As Quest noted, "In the federally mandated, safety-sensitive workforce, positivity for post-accident urine testing jumped more than 51% year over year (3.1% in 2017 versus 4.7% in 2018) and increased by nearly 81% between 2014 and 2018." But the report is clear that prescription opiates were the primary driver in 2018.

This, of course, isn't the case with a handful of recent state-level studies. One 2018 study from the Highway Loss Data Institute finds that while fatalities aren't necessarily up as a result of cannabis use, crashes in recreationally legal states are. In Washington, Oregon, and Colorado, crash statistics have risen as much as 6% since weed was fully legalized.

These are some pretty big hurdles to overcome

This new data brings to light a number of bigger problems.

To begin with, there's no consistent workplace policy when it comes to cannabis, even in legalized states. Some companies test for cannabis, while some do not, and the legality of medical and/or recreational marijuana becomes tenuous when a company tests for a drug that's legal at the state level but illicit at the federal level.

For instance, federal contractor Boeing (NYSE: BA) , which employed just over 153,000 people at the beginning of 2018, has stated previously that it has no intention of changing its drug-testing policy , regardless of the individual states that pass cannabis policies. Boeing's Drug Free Workplace policy is based on federal standards, and according to the federal government, marijuana remains a Schedule I drug. Despite employing a lot of folks in California and Washington state, Boeing is not going to change its policies for these safety-sensitive employees.

It also brings to light concerns over accurate testing. Whereas there are pretty concrete guidelines for peace officers to use when determining alcohol intoxication behind the wheel, such as blood-alcohol content, determining the level of impairment with regard to cannabis consumption isn't easy. Not only do most states lack a concrete guideline, but there's little means to determine recency of use. Tetrahydrocannabinol, the cannabinoid that gets a user high, can stay in a person's system for weeks, making it difficult for an officer, or even a testing company, to determine recency of use.

To be certain, there are solutions in the work for this problem. A couple of companies are working on marijuana breathalyzers that'll aid law enforcement in determining the level of impairment for drivers. These devices are designed to help determine recency of use, too, albeit they're still probably a few years away from real-world application.

There's no doubt that marijuana has been an economic boon and a jobs creator for states that have legalized. But at the same time, its rise has created a host of new problems. This is something lawmakers and the investing public can't sweep under the rug.