Some are looking at the opioid epidemic and marijuana legalization, and others are questioning if drug testing invades the rights of workers.

Employers across the country are worried that a reliable workforce is going up in smoke.

Recent statistics show an increasing number of failed drug tests by job applicants and employees in 2016.

This is putting pressure on companies looking for workers, and on the economy as a whole.

According to Quest Diagnostics, one of the largest organizations involved in conducting workforce drug tests, ”positive” drug tests are at their highest rate in 12 years — the finding was based on more than 10 million workforce drug tests.

Quest Diagnostics has been publishing data on their workforce drug tests since the late 1980s.

“We have ups and downs, but I think what is striking in the 2016 data is the major illicit drug classes: cocaine, methamphetamine, marijuana, have all shown increases across every testing category and nearly every specimen type,” Barry Sample, PhD, a senior science and technology director at Quest, told Healthline.

For many, the question of the rise in failed drug tests is. “Why?”

Is it a symptom of the opioid epidemic? Marijuana legalization?

It’s hard to say for certain at this point. However, as a recent story in The New York Times pointed out, policy makers and experts are starting to pay attention to how certain drugs are affecting the economy.

“I don’t know that you can summarize it as being any one thing,” said Matthew Nieman, a lawyer who serves as general counsel for the Institute for a Drug-Free Workplace.

It’s clear, however, that the opioid epidemic has taken a toll on human life, as well as on the economy.

According to The New York Times, a federal study conservatively estimated that prescription opioid abuse cost the U.S. economy nearly $80 billion in 2013.

Federal Reserve Chairwoman, Janet L. Yellen, also commented that opioid abuse was part of declining participation in the workforce.

However, of the drugs in Quest’s reporting, heroin detection actually plateaued while prescription opiates declined. Sample explained that they could be looking at two different data sets.

“Perhaps [opioid] use by those subject to workforce drug testing is declining,” he said.

If Yellen and Sample are right, it would indicate that although opioid prescription abuse is rampant, users simply aren’t showing up to work.

Marijuana, on the other hand, has seen an uptick in positive drug tests, according to Quest.

Not only has it increased nationally, but on the state level there have also been dramatic changes.

This year, Quest paid close attention to two states where recreational marijuana usage is legal: Colorado and Washington. Those states could serve as potential litmus tests for the effects of legalized marijuana on positive workforce drug tests.

In these two states, prior to 2016, the rate of change for drug positivity in the workforce increased more than the rest of the country, said Sample.

More positive marijuana test results following legalization make sense, according to advocacy groups.

“Predictably, increased rates of adult cannabis use — particularly among those residing in legal states — is associated with an increased prevalence in those testing positive on workplace mandated drug tests,” says Paul Armentano, deputy director of the National Organization for the Reform of Marijuana Laws (NORML).

“This increase in positivity should not overshadow the more important reality that these policy changes are not associated with any demonstrable adverse impact in workplace safety, productivity, or participation,” Armentano told Healthline.

Those using marijuana who live in states with medical marijuana and/or recreational usage laws are in a bind.

“The fact that a state has legalized marijuana doesn’t mean that an employer can’t continue to drug test. If a state legalizes the police can’t arrest you, but your boss can still fire you,” Lewis Maltby, president of the National Workrights Institute, told Healthline.

The debate surrounding workforce drug testing becomes incredibly delicate when viewed from Maltby’s perspective.

For both marijuana advocates and workers’ rights advocates, the attitude of employers seems overtly hostile toward marijuana.

“When people like me have been pointing out to employers that there’s no difference in job performance between pot smokers and social drinkers, employers always say, ‘But, marijuana is illegal, that’s why we treat it differently.’ So now, marijuana isn’t illegal in some states and employers still treat it differently than alcohol,” said Maltby.

The response is always the same.

“From an employer side the issue has never been what is the substance, so whether we’re talking about opiates or marijuana or cocaine, it’s about safety,” Nieman told Healthline.

Employers interviewed by The New York Times echoed that opinion, particularly those in heavy industry.

“If something goes wrong, it won’t hurt our workers. It’ll kill them — and that’s why we can’t take any risks with drugs,” one said.

Safety is the framework that allows companies to drug test. And turning down an applicant who fails a drug test may make sense to employers, regardless of the substance.

“You’d much rather avoid the accident altogether than figure out after the fact what happened,” said Nieman.

Few jobs have federally mandated drug testing. Those that do are typically in transportation: pilots, truck drivers, train operators, etc. Other occupations deemed “safety sensitive” may also be subject to the federal mandate.

The majority of jobs, however, are not.

Private employers have the leisure of choosing whether or not to conduct the tests — and when. Companies, including Quest Diagnostics, provide testing for both federal and private institutions, but there is little oversight over private company drug testing.

An individual’s rights regarding drug testing vary from state to state, but, Maltby cautioned, there are few options left to an employee or potential hire if they fail.