A 2018 study by Quest Diagnostics found that "increases in positivity rates for marijuana in the general U.S. workforce were most striking in states that have enacted recreational use statutes since 2016. Those states include: Nevada (43%), Massachusetts (14%) and California (11%). These three states also saw significant increases in marijuana positivity in federally-mandated, safety-sensitive workers: Nevada (39%), California (20%), and Massachusetts (11%)." Per Quest's senior director of science and technology: "These increases are similar to the increases we observed after recreational marijuana use statues were passed in Washington and Colorado. While it is too early to tell if this is a trend, our data suggests that the recreational use of marijuana is spilling into the workforce, including among individuals most responsible for keeping our communities safe."