More states are legalizing the recreational use of marijuana, and it seems that companies are now seeing the impacts of such legislation. According to the Quest Diagnostics Drug Testing Index, the rate at which employees in the general U.S. workforce are testing positive for marijuana following on-the-job accidents is at its highest level in a quarter century.

Quest reports that post-accident marijuana positivity rose to 7.3% in 2022 from 6.7% in 2021. That’s the highest the rate has been in 25 years. In fact, Quest notes a steady increase in such positivity each year starting in 2012. Within the past decade, post-accident marijuana positivity has increased by more than 204% while those rates saw a decline from 2002 to 2009.

The diagnostics company says the increase corresponds with marijuana legalization in a number of states. For example, Colorado and Washington State both legalized recreational marijuana use in 2012, with 19 states and Washington, D.C., following suit since that time. Even more states, 38, have legalized medical use. Both recreational and medicinal use of marijuana are illegal under federal law.

“Intoxicating cannabis products, including marijuana, can have a major impact on safety at work and have been proven to slow reaction time, impact memory and impair skills essential to driving. State legalization of the drug creates new challenges for employers,” says Katie Mueller, a senior program manager at the National Safety Council focusing on cannabis safety. “The Quest data provide compelling evidence that increased use of cannabis products by employees can contribute to greater risk for injuries in the workplace.”

The combined U.S. workforce urine drug positivity for all drugs remained at 4.6% in 2022, which is still the highest level in 20 years. Positivity rates for 2021 and 2022 were the highest since 2001, increasing by more than 30% from all-time lows in 2010-12. Quest also notes that marijuana is not the only culprit.

“Positivity for marijuana in the general U.S. workforce increased 10.3% … amphetamines positivity increased 15.4% … While the company’s data for amphetamines does not differentiate between prescribed medications and illicit drug use, the increase correlates with other data suggesting that the use of amphetamines, prescribed or illicit, has grown in recent years in the U.S.”

Certain industries are experiencing increases in marijuana positivity more than others. Accommodation and food services, retail trade and finance and insurance top the list. When looking specifically at states that permit medical and recreational use, the federally-mandated safety-sensitive workforce, including pilots and some federal positions, experienced a 14% year-over-year increase. In 2022, marijuana positivity increased by 17% in states with legalized recreational marijuana. That rate increased by 5.9% in states with legalized medical marijuana.

Marijuana positivity also increased in states without any form of legalization, rising 12.7% year-over-year. However, Quest notes that positivity rates are still higher in states with marijuana legalization.

“Our 2022 Quest Diagnostics analysis shows that the overall U.S. workforce positivity rate continued to be at a historically elevated level in 2022, even as much of the nation’s workforce returned to the office post-pandemic,” says Keith Ward, general manager and vice president for employer solutions at Quest. “This historic rise seems to correspond with sharp increases in positivity for marijuana in both pre-employment and post-accident drug tests, suggesting that changing societal attitudes about marijuana may be impacting workplace behaviors and putting colleagues at risk. The increase in amphetamines positivity is also notable, given the addictive potential and health risks associated with this class of drugs.”