A new study by UC Davis found samples of medical marijuana from Northern California that contain potentially deadly bacteria and fungus.

The state of California will mandate dispensaries do testing starting January 1, 2018. Until then, there is no real penalty for dispensaries that do not test.

“In general the better quality dispensaries, those are the ones getting lab testing because it’s not required,” said Samuel David, the CEO of Coastal Analytical Labs in Vista.

He says some dispensaries have their marijuana tested for potency, or THC levels. However because the other tests are expensive, they may opt out of having them done.

“The state’s mandating five. That’s potency, terpenes, micro bacterial, residual solvents, and pesticides,” he says.

Medical marijuana patients with low immune systems may really want to pay attention to the last three. High levels of certain bacteria, and pesticides could be dangerous, especially for those fighting leukemia, lymphoma or AIDS.

“We want immunocompromised patients to be aware of the risks,” says UC Davis Dr. George Thompson, author of the original study. “Vegetative products by nature contain a host of bacterial and fungal microbes. Directly inhaling these provides access, and potentially pneumonia, in those with weakened immune systems.”

There are some simple ways you can minimize your risk. David says just ask what tests your dispensary does.

If you’re using an online service like WeedMaps, it may be worth calling before you place an order. Ultimately, until law mandates tests next year, it’s on you to be your own advocate.

“People have been smoking weed for thousands of years,” David said. “But would I want to know? Absolutely. So I would test for it and I would ask for the results.”

Original Article via NBCSanDiego