THC In Seattle Water 'Highest Detected In The World'

SEATTLE, WA - Perhaps it shouldn't come as a surprise that there's a lot of THC in Seattle's water - after all, it's the largest city in a state that has legalized recreational marijuana. But the highest levels of THC in the world? That's what a new University of Washington study on drug use found.

"Based on the current science, it appears that the level of carboxyTHC measured was among the highest detected in the world," the researchers wrote in the paper.

UW researchers in 2016 tested Seattle's wastewater to get an idea of how prevalent marijuana use is. They found that the rate of THC in Seattle water is about 416 milligrams per 1,000 people. A joint filled with a gram of marijuana will likely contain, on average, 18 milligrams of THC, according to High Times Magazine.

Seattle's population in 2017 stands at about 704,000 people, which means there's an estimated 300,000 milligrams of THC in total in Seattle's water. That's about 17,000 individual joints, if High Times' math is correct.

And although they claim Seattle's water is the most THC-infused on Earth, they also have to hedge that claim. Seattle is the only city in the U.S. that participates in an international wastewater drug monitoring program. So it's impossible to tell if cities in other legal states - Oregon, Colorado, California - have higher THC levels in wastewater.

"Note that wastewater testing for drugs is an area of evolving science and that THC and 2016 metabolites are complicated to analyze chemically and statistically so results can be difficult to interpret and compare over time and between locations," the researchers wrote.

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