Tens of thousands of vaping cartridges holding high concentrations of the active ingredient in marijuana were seized from a home in Coon Rapids this week in what authorities say is the largest haul of its kind in the state.

Many of the 75,000 cartridges were in packages illustrated with younger users in mind. Some sported famous cartoon characters or themes of sweet flavors. One called Fruity Pebbles showed a smiling Fred Flintstone. Cherry Kush, Candy Land and Strawberry Shortcake were among the other names.

Unlike legally purchased medical marijuana products that are tested by state regulators, health experts say the ingredients inside illicit vape cartridges aren’t always clear.

“We urge everyone: Do not use illegal THC cartridges. They can be very dangerous,” Daniel Huff, an assistant commissioner with the Minnesota Department of Health, said at a news conference Tuesday. “You just don’t know what’s in them.”

Officers seized the stash of preloaded THC cartridges from a condominium Monday in the 3600 block of Coon Rapids Boulevard and arrested a 22-year-old man from Champlin. The inventory had an estimated street value of $3.8 million.

The drug bust comes amid a nationwide health scare triggered by nine vaping-related deaths, including one in Minnesota of a patient older than 65 who died in August after a prolonged hospitalization. While the person suffered from an underlying lung disease, further review determined the hospitalization was due to a lung injury associated with vaping an illicit THC product, state officials said. The patient’s age is unusual; the majority of people hospitalized in Minnesota for vaping-related lung injuries have been in their teens and early 20s.

Overall in Minnesota, state epidemiologists have counted 43 confirmed and probable cases of vaping-related illness and another 24 are under review. All 43 individuals reported smoking THC e-cigarette products, but many also used nicotine.

Since 1995, law enforcement agents say the average marijuana leaf potency has more than tripled from 4 to 14%. But today, many black-market vape cartridges test in excess of 90% THC content — a potency health experts say is extremely dangerous.

“You can put vitamin E oil on your skin, you can ingest it; we just don’t know the impact of what it does when you inhale it,” Huff said. “That’s the danger of vaping. We have not studied the health impacts of what vaping does to one of our most sensitive organs.”

Health officials have been trying to counter the rise in vaping, especially among teenagers who view it as a safer alternative to smoking and like the fruity flavors. A new national survey found that vaping among high school-age students doubled from 2017 to 2019 and that 1 in 9 high school seniors use e-cigarettes daily, according to the New England Journal of Medicine.

‘Hundreds more’ illnesses

In Washington, D.C., a public health official said Tuesday that the number of vaping-related illnesses in the U.S. could soon climb much higher.

Anne Schuchat, of the Centers for Disease Control and Prevention, told a congressional subcommittee that she believes “hundreds more” lung illnesses have been reported to health authorities since last Thursday, when the CDC put the tally at 530 confirmed and probable cases.

While the CDC has yet to identify a common electronic cigarette or ingredient, the illnesses, which resemble an inhalation injury, have helped trigger a swift backlash against e-cigarettes. The Trump administration has proposed a federal ban on flavors, and state-level restrictions are in place in Michigan and New York. Walmart ended vaping sales nationwide.

“Have conversations with your kids, with your loved ones,” said Brian Marquart, statewide gang and drug coordinator for the Minnesota Department of Public Safety’s Office of Justice Programs. “Stop using them. Get help. Go to treatment. … Don’t wait until it’s too late.”

Authorities first got wind of the Minnesota trafficking operation in July from a confidential informant, who told law enforcement that the suspect “sells large quantities of THC cartridges, commonly in the thousands,” according to the search warrant affidavit.

An undercover officer from the Northwest Metro Drug Task Force purchased vape cartridges from the suspect while under surveillance by other team members, who then followed the man to his home. A search of the residence and nearby vehicles Monday yielded many of the cartridges in the garage but also in each bedroom and near the living room, according to a search warrant inventory filed in Anoka County District Court.

Also seized from the property were THC gummies, prerolled marijuana cigarettes, marijuana vials and more than $23,000 in counterfeit U.S. currency.

Court records show that the suspect has three convictions for drug-related crimes, two of them felonies. His most recent conviction put him on probation until March 2021.

He remains jailed as the County Attorney’s Office sizes up the case for charges. The Star Tribune generally does not identify suspects before they are charged.

Next-door neighbors, who were unaware of the arrest or the bust, described the man and his 20-year-old girlfriend as model residents who rarely, if ever, got deliveries. Neighbors say they had not noticed any suspicious behavior at the condo complex.

New Hope Police Chief Tim Fournier praised the seizure Tuesday but offered a cautionary note as voters consider legislation to legalize marijuana.

“If you think this is a problem now, wait until cannabis products become commercially available in Minnesota,” he said. “This is yet another example of why we should pause, take our time before passing similar laws in this state. Black-market suppliers don’t go away when you legalize this kind of product.”

Star Tribune staff writer Jeremy Olson and the Associated Press contributed to this report.