On Monday, St. Charles County passed an emergency ordinance banning K2 and similar substances, and other Missouri lawmakers are looking to do the same. In the meantime, some stores are reporting a spike in K2 sales while some people who have tried this marijuana substitute are reporting adverse reactions, such as hallucination.

How does a mixture of dried herbs and spices attract so much attention and alarm?

Here's a look at what all the buzz is about.

What exactly is K2?

Also known as "spice" or "fake weed," K2 is a mixture of herbs and spices with different aromas that's often marketed as incense but can be smoked as a legal substitute for pot. It's purported to give users a similar -- and in some cases more potent -- high, although some have questioned that assertion.

According to Anthony Scalzo, a professor of toxicology at St. Louis University and the director of the Missouri Poison Center at Cardinal Glennon Children's Medical Center, the herbal mix is sprayed with "a potent psychotropic drug."

Who sells it?

A variety of smoke shops and convenience stores offer K2, which sells for roughly $36 to $40 for a three-gram bag. It's also available over the internet.

Why the local attention?

Scalzo said he's been contacted over the last six weeks by a range of emergency-room physicians reporting patients with adverse reactions to K2. (He's been consulted on roughly 30 such cases across the state.) "It's up and coming -- the frequency of problems is increasing," he said.

What are the symptoms?

They can include hallucination, severe agitation, elevated heart rate and blood pressure, vomiting, tremors, seizures and pale skin.

Who are these patients?

Most of the documented cases in Missouri of people seeking medical attention involve people between 14 and 21.

What's the greater medical concern?

The synthetic compound JWH-018, named after John W. Huffman, the Clemson University chemist who first synthesized it in the mid-1990s, is, according to the Missouri Poison Center, purportedly sprayed on the dried herbs and spices to make K2. JWH-018 typically makes users calm and relaxed. But some people seeking medical help are experiencing the opposite effects, which concern researchers like Scalzo. He said patients' symptoms suggest that the drug affects users' cardiovascular and central nervous systems, and some people are experiencing vastly increased heartbeats and blood pressure at "urgent levels."

Huffman, for his part, has said that the synthetic drug isn't meant for recreational use.

Why are patients experiencing these symptoms?

It remains unclear. Scalzo said that elevated amounts of JWH-018 might be responsible for the hallucinations, but the Missouri Poison Center put out an alert saying that it does not suspect that the health problems users are reporting are due to this synthetic cannabinoid.

K2 is an unregulated substance, which means one batch can be different from the next. In some cases, K2 may be contaminated with an unknown toxic chemical causing the adverse reactions.

Scalzo emphasizes that not all K2 might be contaminated in this way, and that there are useful synthetic chemicals. "I'm concerned with some bad batches or perhaps excessive doses of the cannabinoid in some K2 products," he said.

Scalzo is working with university researchers, the Centers for Disease Control and Prevention and the Missouri Department of Health and Human Services to study how the synthetic compound affects the human body. SLU's forensic toxic laboratory is looking to study patients' urine samples for possible contaminants, but Scalzo said many patients are hesitant to agree to participate.

Is K2 usage really a widespread problem?

It's hard to say. The Missouri Poison Center said the use is "likely widespread ... and appears to be big in St. Charles, Greene (Springfield), West Plains and some mid-Missouri counties."

Scalzo said in an e-mail that "there is a public health concern, it's not thousands of individuals but many cases in the Midwest are now cropping up around the country."

Physicians in other states report seeing patients displaying alarming symptoms, and poison control centers are spreading the word about the danger of K2 across the country.

Dan Duncan, director of community services with the National Council on Alcohol & Drug Abuse - St. Louis, said although he's heard anecdotally that K2 is widely used, he has his doubts. Counselors at his health agency haven't been hearing about it or seeing increased use among young people.

Duncan said the news media have brought a lot of attention to K2 and he fears that the coverage only makes people more likely to try it. That criticism has come from many corners, including a recent piece in Newsweek that says fears of a K2 crisis are premature. 

Still, Duncan said, if K2 is as damaging to users as what's being reported, "there's plenty of reason to be alarmed."

What are the political ramifications?

Last month Kansas became the first state to pass legislation banning K2, and the bill is awaiting the governor's signature.

Missouri lawmakers are considering similar legislation. State Rep. Ward Franz, R-West Plains, introduced a bill to place the compounds in K2 and similar products on the state's list of controlled substances. Debate on the bill has begun on the House floor. The Senate is also considering a bill, introduced by Sen. Kurt Schaefer, R-Columbia.

Meanwhile, the St. Charles County Council passed an emergency bill on Monday night that makes it a misdemeanor to possess or sell products containing synthetic cannabinoids, known or sold under product names like K2. The bill, requested by St. Charles County Sheriff Tom Neer, goes into effect immediately, but penalties for violating the ban won't be enforced until next month.

Expect to see more debate and legislative action in the coming weeks.