When you take a hit of marijuana, you might be inhaling a lot more than pot.

During a recent presentation at Humboldt State University, Jeffrey Raber said a recent study he conducted found that up to 70 percent of the pesticides found on a marijuana bud can transfer to the smoke being inhaled.

”I think that what’s so alarming to us is that such a huge amount of pesticide material could be transferred,” Raber said. “And, you have to consider that when you inhale (something), it’s much like injecting it directly into your blood stream.”

Raber — who holds a PhD in chemistry from the University of Southern California and runs The Werc Shop, a medical cannabis testing laboratory in Los Angeles — spoke at HSU earlier this month as the latest speaker in the Humboldt Institute for Interdisciplinary Marijuana Research’s lecture series.

Titled “Medical Cannabis Quality Control in California: Keeping a Weed Free Garden,” Raber’s talk covered an array of topics focused on laboratory testing of marijuana, including the dangers of lurking contaminants and pesticides.

On the pesticide issue, Raber said it’s important to remember that smoking a marijuana bud that’s been sprayed with chemicals is far different than eating a non-organic tomato. First and foremost, he said, there are no controls over what’s sprayed on marijuana crops. And, while most people would rinse off a tomato before eating it, they can’t wash a bud before putting it in their pipe. The body also has filters in place for things that are ingested, he said, but not for what’s inhaled.

”You don’t have the first pass metabolism of the liver,” he said. “You don’t have the lack of absorptivity going through the stomach or the gut lining. It’s a very different equation when you’re inhaling.”

Raber said about 10 percent of the marijuana that comes through his laboratory for testing registers positive for pesticides. Those samples are only from medical marijuana dispensaries and patients who have sought out testing, he said. In a small random study his laboratory performed, Raber said more than 35 percent of marijuana failed pesticide tests.

”I think all that says is we really, really need some serious regulations within California to help us clean up our supply, especially in the medical patient context,” Raber said. “These are people that are immunocompromised, they’re undergoing chemotherapy, they’re very sick with antibacterial loads. We can’t be subjecting them to more of these types of potentially harmful contaminants when they’re looking to this as a medicine source.”

Humboldt County Sheriff Mike Downey said his deputies have been finding massive amounts of high-powered pesticides at marijuana gardens throughout the county, many of which have posted medical marijuana recommendations — meaning the marijuana grown there could be heading for collectives and, ultimately, to patients.

”I would be very concerned if I were a consumer,” Downey said.

Downey said he’s been looking for a study like Raber’s to quantify the dangers of smoking pesticide-laden marijuana, and he hopes to see more.

”I think there needs to be some type of direct evidence of what (patients) are getting, what they’re smoking, so the general public can start to understand what they’re dealing with,” Downey said.

Raber’s study only goes so far. He said his laboratory tests for 30 to 40 types of chemicals, and works off the United States Environmental Protection Agency intake limits for things like apples and pears. It’s far from an exact science, and he said his laboratory hasn’t done any testing looking at variations between specific pesticides.

Downey said he’d like to see some studies specifically looking at cumulative impacts of inhaling these substances over the course of years, or even decades.

Mary Ellen Jerkavich, executive director of the Humboldt Patient Resource Center, said she believes marijuana is inherently a safe product, but is being turned into something decidedly unsafe by growers looking to maximize profits or save their crops by any means necessary when spider mites or other pests strike.

”When you (use pesticides), you’ve turned it into something different,” she said. “It’s crazy. It’s super scary.”

Jerkavich said her center grows all of its own product and doesn’t use pesticides or other chemicals. The center sends samples to be tested, she said, trying to make sure it is offering patients a reliably consistent product. When initially looking for a testing laboratory, Jerkavich said the center sent samples to four labs to test for levels of THC, Cannabidiol and Cannabinol. Each lab returned vastly different results, she said.

That touches on another problem with the industry, according to Raber, who said that just as there is no licensing or oversight of growers, there is none for testing laboratories either.

”Unfortunately, today in California, anyone can pretty much call themselves a lab, which is sometimes pretty demeaning to the word,” he said. “There’s no qualification.”

The pesticide issue was just a small point in Raber’s larger talk at HSU, which touched on everything from erroneous branding at dispensaries and testing procedures to the various components of marijuana and the ways to determine the best strands to treat specific ailments. One theme was consistent, however.

”Buyer beware,” Raber said. “You should really look for lab-tested products. … With no regulations and no quality control, anything that can be brought out to the market will go out to the market.”

Downey, who has gotten a close-up look at the some of the supply side of that market in Humboldt County, said the state really needs to step up to the plate and regulate the marijuana industry.

”We have legislators that are supposed to be dealing with this kind of thing, but they continue to bury their heads in the sand,” Downey said. “I think the general public is at risk. Where is the common sense in this? There is none.”

On the web:

To view Raber’s full lecture, visit http//humboldt-dspace.calstate.edu/bitstream/handle/2148/1628/HIIMR_Raber_video/html?sequence=5

Thadeus Greenson can be reached at 441-0509 or tgreenson@times-standard.com. Follow him on Twitter @ThadeusGreenson.