The percentage of working Americans testing positive for drugs hit a two-decade high last year, driven by an increase in positive marijuana tests amid loosened screening policies amid labor shortages. Of the six million general workforce urine tests that Quest Diagnostics screened for marijuana last year, 3.9 percent came back positive an increase of more than eight percent from 2020. That figure is up 50 percent since 2017. Since then, the number of states legalizing recreational marijuana grew to 18 from eight, plus the District of Columbia. Despite the increase in positivity last year, fewer companies tested their employees for THC, the substance in marijuana primarily responsible for its effects said Quest's Barry Sample, the Wall Street Journal reports. The shifting legal situation and changing cultural attitudes have prompted some employers to stop marijuana testing. Companies in some states are barred from factoring the test results into hiring decisions. Those trends accelerated last year amid the recent shortage of workers, especially in states where recreational marijuana is legal. The percentage of specimens tested for THC declined 6.7 percent nationwide in 2021 from 2020, while that figure fell by 10.3 percent in states where recreational marijuana is legal. “We certainly heard from some of our employer customers that they were having difficulty finding qualified workers to pass the drug test,” said Quest's Sample. Overall, the proportion of U.S. workers who tested positive for the various drugs Quest screened for in 2021 rose to 4.6 percent, the highest level since 2001.