The release this January of the first dissolvable tobacco product by a major company has some public health officials concerned.

"This is a wake-up call for the public health community," says Gregory Connolly of Harvard School of Public Health. "It's a total sea change."

For smokers who can't light up in the office or at a restaurant, a new aspirin-sized tablet, called "Camel Orb," will let tobacco melt in their mouth. The dissolvable product — arriving January in stores in Portland, Ore., Columbus, Ohio, and Indianapolis — is the first such product by a major tobacco company and is part of a booming market in smokeless alternatives to cigarettes as smoke-free laws sweep the nation.

"It's meeting the needs of smokers," says Rob Dunham, of R.J. Reynolds, maker of Orb and Camel cigarettes. With lozenge-like Orb, he says there's no smoke, no spit, no litter.

In the past two years, the nation's two largest cigarette companies, R.J. Reynolds and Philip Morris USA, have moved into the smokeless tobacco market as cigarette sales continue to fall. Each introduced smokeless pouches or "snus, " touted as spit-free products that sit inside the mouth. They also bought smokeless tobacco companies.

"We've been very pleased with the consumer response" to Marlboro Snus, says David Sutton, spokesman of Altria Group, which owns Philip Morris USA. He says smokeless is a "growing category" with sales rising 6%-8% annually. He says cigarette sales are falling 2%-3% each year.

Many public-health advocates are alarmed.

"These products are designed to enhance social acceptability of tobacco," says Connolly. "They've left the realm of traditional tobacco products" and are more akin to food. He says they may pose fewer health risks than cigarettes because they are smokeless, but he says they're dangerous because they keep people addicted. Also, he says, they're attractive to kids, because they're easy to hide.

Cigarette smoking rates among U.S. teens continued to fall last year but their smokeless tobacco use remained stagnant, according to the annual Monitoring the Future study at the University of Michigan.

Teens like risk-taking behavior and a tablet, unlike a cigarette, won't lure them, says Sara Troy Machir, spokeswoman of Star Scientific, a small tobacco company that sells two dissolvable products, Ariva and Stonewall.

After Ariva began selling in 2001, a coalition of public health groups asked the Food and Drug Administration to regulate it as a food but FDA said it was tobacco. Under a pending bill in Congress, which President-elect Barack Obama supports, the FDA would be given authority to regulate tobacco products.