PORTLAND, Ore. (KOIN) — A recent study revealed that drugs like methamphetamine and fentanyl are found in the air and on the surfaces of public transit vehicles in Oregon and Washington.

Although researchers determined that the small traces of drugs weren’t enough to pose a health risk to passengers or drivers, TriMet is still looking to crack down on drug use in its vehicles.

The University of Washington conducted this study with funding from five transit services: TriMet, King County Metro, Community Transit, Everett Transit and Sound Transit.

On 28 nights from March 27 to June 22 of this year, researchers gathered air and surface samples of fentanyl and methamphetamine in 11 buses and 19 train cars.

The data was collected during times and routes that transit employees identified as popular for drug use. Additionally, the samples were taken near operators and other areas where smoke typically accumulates.

“A work environment that includes drug use and drug smoke can make it harder for transit operators to safely and effectively do their jobs, regardless of the level of exposure that operators may face,” Dr. Marissa Baker, an assistant professor at UW, said.

Across all of the transit vehicles, 98% of the surface samples and 100% of the air samples tested positive for methamphetamine. For the fentanyl tests, 46% of the surface samples were positive and 25% of the air samples were positive.

The tests didn’t determine whether secondhand fentanyl or methamphetamine was detected in the drivers’ systems, nor did it determine if long-term exposure can lead to permanent health effects.

Still, researchers say transit services should consider the physical and mental health conditions that operators face as a result of drug exposure.

“The potential long-term health effects associated with daily exposure have not been adequately researched, so until these relationships are established, we’re suggesting protective measures that transit agencies could implement to keep operators safe,” UW Research Industrial Hygienest Marc Beaudreau said.

After the results of the assessment were released, TriMet issued a statement on its efforts to curb drug use in its vehicles.

The transit service noted that smoking is prohibited on all buses, trains, MAX and WES platforms, etc. Anyone who violates this policy faces a fine of up to $175 and could be banned from riding.

“We’ll continue doing everything we can to keep drug use off of our buses and trains,” the TriMet statement said. “But we can’t do it alone — and we urge our state and local leaders and our law enforcement partners to address drugs and addiction in our community.”

“Smoking in all forms is prohibited on TriMet vehicles, on platforms, and that’s part of us increasing a security presence is limiting that behavior,” added Andrew Wilson, who is in charge of TriMet safety.