GRAND HAVEN -- As a disabled U.S. Army veteran, Dan Higgins suffers severe nausea from pain medication for his damaged back.

The only thing that helps, he said, is marijuana.

Today he plans to be in Lansing as Michigan's medical-marijuana law, approved by voters in November, takes effect. On Monday, the state Department of Community Health begins accepting applications from those with doctors' permission to use marijuana.

For Higgins, 34, of Grand Haven, the law is based on compassion. "It's to give people their medication. ... I just can't keep the food down."

But, he said, there's this, too: "This is marijuana. It's not cocaine. It's not heroin."

MARIJUANA AS MEDICINE

Key points of the law, which goes into effect today:

• Qualified users can possess 2.5 ounces of usable marijuana or grow as many as 12 plants. Designated caregivers can provide that amount to a patient and supply as many as five patients.

• The state compiles a confidential database but will verify to police if an individual is registered.

• Registered users cannot use marijuana while driving; possession is banned in school buses, schools and correctional facilities, and smoking is prohibited on public transportation or public places.

• Employers may prohibit use at work.

The ballot initiative took effect Dec. 4, but no one could apply for six months while the Department of Community Health developed administrative rules. The law provided medical-marijuana patients a defense to charges, but criminal penalties will be gone for those with an identification card.

While the proposal was framed as a way to help seriously ill patients, many area police leaders warned it was a step toward legalization and that it put motorists at risk and threatened families.

Kent County Undersheriff Jon Hess has worked with police agencies in California, Oregon and Washington, which have medical marijuana laws. He said he has concerns because other states reported that marijuana laws have become "so watered-down."

The Sheriff's Department was trained in the new law and continues to study information from the Department of Community Health.

In other states, police report those busted for illegal possession of pot sometimes say they are legal medicinal users, and, Hess said, "I anticipate there will be those that try to use this as an excuse."

In Ottawa County, the Sheriff's Department has "opened a line of communication" with a Holland-area Compassion Club, one of numerous such groups across the state.

"We recognize that legislation has been changed allowing manufacture and use of marijuana under very specific guidelines," Ottawa County Undersheriff Greg Steigenga said. "It's our intention to work within established guidelines as a law-enforcement agency that is also commissioned to enforce the law of illegal propagation of marijuana."

Police are used to changes in the law, but this is a little unusual.

"We'll work through it. It's something that's new for the entire state," Steigenga said.

He said the new law provides guidance for police and legal users and appeared fairly straightforward. But he expected legal challenges.

So does Grand Rapids attorney Bruce Block, who has researched marijuana laws and put information on his Web site. He also represents perhaps the area's most high-profile alleged user, suspended Press columnist David Mayo, busted after police tracked growing equipment he bought from an advertiser in High Times magazine.

He sees a lot of problems, including driving laws that hold motorists responsible with any amount of drugs in their system.

"That's one of the Catch 22s," he said.

The federal government said it won't target medical-marijuana users or growers, but "technically, it is still illegal" under federal law, Block said.

Also, "Where do you get the seeds or the plants? ... If someone has a medical-marijuana card, they are basically buying from someone on the street. People selling to them can still be busted," Block said.

Greg Francisco, executive director of the Michigan Medical Marijuana Association, said the number of underground users is large and includes those from all backgrounds and professions. He discounted the notion that prescribed drugs better relieve nausea and pain.

"I kind of believe the patients," Francisco said.

E-mail John Agar: jagar@grpress.com