California is set to legalize recreational marijuana on January 1st. And while most people are excited about the impending changes, some experts are warning of potential dangers in the new year.

Some experts are warning about the quality of marijuana that will be available when the new year begins. While the drug will now be legal, there are no legal testing requirements that cannabis must undergo before hitting the shelves. While California will institute stricter testing guidelines for marijuana, existing growers are being given a six-month grace period to sell off their existing crops before those new laws take effect.

Donald Land, a chemistry professor at University of California-Davis, made headlines earlier this year when he found that 93 percent of marijuana samples he obtained from California dispensaries tested positive for pesticides. There was also a significant percentage that contained mold and other contaminants as well. So perhaps those same qualities will be found in marijuana being sold in 2018.

Of course, medical marijuana has also been legal in California for two decades with the same amount of regulation on cannabis growers that will be in effect for the new year. And it doesn't seem like there are any health problems or issues related to contaminated marijuana in the past, so it may just be doomsayers predicting widespread plague from cannabis.

(h/t Associated Press)