Branford resident Alex London uses cannabis to help with lingering back pain and migraines that stem from a car crash.

London said he used to buy it from medical marijuana dispensaries near his home. But now, because of changes in how Connecticut regulates cannabis, he’s back to using his “local guy” — a grower in Maine.

“At least with him, I’m aware of where it comes from,” London said.

That matters for London because he’s worried about the amount of mold in the marijuana he smokes.

Mold is present wherever we go: It’s in our food, our medicine and our air. Because avoiding mold entirely is impossible, the U.S. Food and Drug Administration allows for small amounts of it in lots of consumer products. But because marijuana isn’t legal at the federal level, it’s up to states to decide how much mold in the product is too much.

And in Connecticut, that limit has been in flux. It’s currently set at 100,000 colony-forming units per gram of cannabis (a measurement expressed as CFU/g). A review by The Accountability Project found that that’s 10 times higher than the threshold in most other states that have a numeric limit for mold in marijuana.