After a dozen people in Newark, New Jersey, became ill from the synthetic marijuana K2 this week, activists say legalizing pot could help bring an end to such incidents.

Since a state law banning those substances went into effect four years ago, authorities say reports of poisonings have declined.

Bruce Ruck with the New Jersey Poison Education and Information System said calls are down to the poison center about the products treated with chemicals designed to mimic the effects of marijuana.

"We have seen those numbers go down somewhat," he said. "I think there is other stuff on the market taking its place, hard to say what that is, and as you knock one thing down something else tends to pop up."

The synthetic marijuana products are dangerous, Ruck said.

"They cause significant agitation, significant hallucinations. They can cause other side effects as well," he said. "There are reports in various states where some people have developed renal failure from it."

Thursday night, Newark police responded to a report of a sick person foaming at the mouth in the city. When they arrived at the scene, they found a dozen people experiencing similar symptoms.

They were taken to area hospitals. No fatalities have been reported.

Roseanne Scotti with the Drug Policy Alliance said the continued use of the synthetic pot bolsters the case for legalizing the recreational use of marijuana in New Jersey.

"Give people safe, legal access to marijuana, and they're not going to be using these dangerous substances that they're getting from who knows where," she said.

It's unlikely New Jersey will legalize recreational use in the state anytime soon. Gov. Chris Christie adamantly opposes such a move.