Some pilots, truck drivers, rail operators, and bus drivers are flunking their drug tests, according to a new study.

A newly released survey from Quest Diagnostics of federally mandated "safety-sensitive workers," who must receive pre-employment as well as random drug and alcohol testing, found a 33% jump in testing positive for cocaine during 2011.

The data, collected from 1.6 million drug tests done last year, also show a nearly 26% spike in testing positive for amphetamines.

These upward trends come on the heels of stricter government drug testing rules, which took effect in October 2010, along with new lower drug testing cutoff levels for substances, such as cocaine and amphetamines.

At the same time, the U.S. Department of Transportation also added a few other substances, including heroin and ecstasy, to its required drug testing list for private and public sector workers in the transportation industry.

These "safety-sensitive workers," who are subject to random drug testing via urine sample, include flight crews, air traffic controllers, ship captains and crew members, subway operators, and locomotive engineers, to name a few.

Whether on the road, rails, water, air, or underground, these workers are put into a distinct category because people count on them to be as clear-headed and alert as possible during their shifts to ensure safety.

But as a recent survey from the National Sleep Foundation found, sleepiness is a common problem for some transportation workers: One in four pilots and train operators admitted to feeling sleepy on the job to the point that it affected their performance at least once a week.
An Upswing in ‘Uppers’

An estimated 12 million transportation workers in the U.S. are subject to these new drug testing rules.

Safety-sensitive workers tested positive for cocaine at the highest levels since 2008, and methamphetamine use was at the highest level since prior to 2007. Both of these drugs are stimulants.

Researchers suspect the increase in positive tests for these substances likely stems from the newly reduced cutoff point, as well as from greater use of prescription medications containing amphetamines to treat ADHD.

Among transportation workers in 2011, testing positive for marijuana was at the lowest levels since prior to 2007.

To give a broader perspective on overall trends and shed light on the potential use of these substances among workers, the survey also included findings from 6.4 million drug tests in U.S. workplaces in general.

Compared to 2010, the number of positive tests in the general workforce for amphetamines is up nearly 17%, and it is up by 75% since 2007. Positive cocaine tests are also up 8% in 2011 compared to the previous year.

Perhaps one encouraging finding from last year's data is that the number of positive drug tests among safety-sensitive workers is lower at 1.7% compared to 4.1% in the general workforce.