A survey conducted by the New York Medical Marijuana Cannabis Industry Association claims it found tainted marijuana at 20 unlicensed businesses in the city.
They say many of them were contaminated with E. coli, salmonella, heavy metals, and pesticides. Those contaminants can cause illness and infection in the human body.
75 percent of the businesses said their product came from California or the West Coast, the survey detailed.
The trade groups estimate that there are likely tens of thousands of illegal marijuana businesses operating in NYC.
The city just recently approved the first licenses to sell recreational marijuana. The Office of Cannabis Management received over 900 applications for those licenses.
The approval of licenses is a major step that came as cannabis regulators stress that they're trying to stop those unlicensed sellers.