Workers and job applicants are testing positive for marijuana at the highest rate in 14 years, due to the legalization of recreational pot in some states.
In 2018, about 4 and a half per cent of workers had positive results for pot, up 5% over 2017.
Quest Diagnostics says an analysis of 10 million workplace tests showed positive tests rose 16 per cent over 4 years.
And the positives are up 24% in safety-sensitive jobs, like pilots, law enforcement, and train conductors.
There are also indications more people are trying to cheat the tests.
From 2017 to 2018, the percentage of urine specimens rejected due to inconsistencies - suggesting attempts at altercation or substitution - jumped 80% in safety-sensitive workforce and 40% in the general workforce.
While marijuana positives were up, those for opioids, heroin, and cocaine fell last year.
More workers and applicants test positive for pot
Positives higher in sensitive jobs like pilots, law enforcement