"We believe it is the largest effort in California to wipe out old criminal convictions in a single court motion," District Attorney Jackie Lacey said.
Many cases of vaping-related injury seem to involve THC, health officials say. That's led some states to take another look at the safety of the regulated cannabis market, as well as the black market.
As the CDC continues to investigate more than 800 cases of vaping-related lung disease, two states have found that many patients were using THC products sold under the label "Dank Vapes."
The country wants to shake its image as an illicit narco nation. Now it's already home to more than two dozen legit cannabis companies, with exports to Canada and the U.K.
The CDC says it is probing 450 reported cases of illness in people who vaped nicotine or cannabis products. Health officials say it's too soon to pinpoint a single product or substance as the cause.
New Yorkofficials say tests found high levels of vitamin E in cannabis vaping products used by people who developed lung damage. But it's only one of many possible causes still under investigation.
As more than 30 states have liberalized marijuana laws, the use and potency of the drug have increased. The surgeon general says there's no safe amount of marijuana for adolescents and pregnant women.
Current federal law limits scientists trying to study the health effects of marijuana to plants from one farm in Mississippi. The DEA says it will begin moving on applications for new growers.