The barricades and signs warning of danger in Montgomery County's approximately 200 parks have had little impact on the summer crowds, according to park officials.

"It's going much more smoothly than I imagined, and there is much less panic than I expected," said Stan Ernst, county parks director, as Montgomery officials proceeded with the clean-up of crushed stone that has been found to contain cancer-causing asbestos fibers.

Ernst said his office gets about 20 calls a day, most of them from groups who want to know if the playgrounds are open.

In bright letters the signs throughout the parks warn that serpentinite rock that "may be hazardous to your health" covers paths and play areas in the parks. The play areas have been barricaded.

The signs do not say so, but the rock has been found to contain dangerous amounts of asbestos fiber that can cause mesothelioma, a fatal form of cancer that does not show up in the lungs of its victims for 20 to 40 years after exposure to the fibers.

Ernst said that playgounds at the four regional parks - Cabin John, Wheaton, Onley Manor and Rock Creek - probably will be reopened by July 1. Play areas at the 23 parks where the recreation department will hold summer programs are expected to be open June 27, starting date for the programs.

Despite the signs and widespread publicity last week when the Environmental Protection Agency urged Montgomery County to close or restrict access to the parks, thousands of visitors were at Cabin John Park one day last week. None of the persons interviewed expressed fear of the harmless looking blue stone that the signs warn against.

At the ticket station for the train that snakes through the park there is a sign warning that the hazardous crushed stone is used on the tracks.

A harried-looking woman with three young boys in two said she didn't care.

"Yes, I read about it in the paper," she said, while paying for her tickets. "But it just doesn't seem that dangerous. It seems like every day they're finding that something else causes cancer. A couple of years ago it was bacon, then saccharin, now gravel. What next? Water?"

One of her sons pulled on her skirt. "Mommy, are we going on the train?" he asked. "Of course," she smiled, then got on the train, the gravel crunching beneath her feet.

The ticker seller, a college student, said business was brisk. "Gee, I've been coming out here 20 years, and I'm not scared," she added.

Striding down the path, her long brown hair swinging behind her, another park employee called a greeting. "I'm going to look at the poisoned blue stone," she said, heading for the playground. She said she "was one of the persons who put the gravel in" but that she did not fear for her health. "I'll live," she said, smiling.

The only park visitor who seemed to have fears was Timmy, a 7-year-old resident of Rockville.As he left he park with his family, he turned to the playground and said, "I hope the fort is still there. They're not going to take it out, are they?"