PITTSBURGH &

To the list of simple childhood pleasures now endangered, add this: eating snow.

A recent study found that snow &

even in relatively pristine spots like Montana and the Yukon &

contains large amounts of bacteria. Parents who warn their kids not to eat dirty snow (especially the yellow variety) are left to wonder whether to stop them from tasting the clean, new-fallen stuff, too, because of Pseudomonas syringae, bacteria that can cause diseases in bean and tomato plants.

But experts say there's no need to banish snow-eating along with dodgeball and unchaperoned trick-or-treating.

"It's a very ubiquitous bacteria that's everywhere," says Dr. Penelope Dennehy, a member of the American Academy of Pediatrics' committee on infectious diseases. "Basically, none of the food we eat is sterile. We eat bacteria all the time."

Children practically bathe in bacteria when they go to the playground, and Dennehy says they won't get anything from snow that they wouldn't get from dirt.

"We eat stuff that's covered with bacteria all the time, and for the most part it's killed in the stomach," says Dr. Joel Forman, a member of the pediatric academy's committee on environmental health. "Your stomach is a fantastic barrier against invasive bacteria because it's a very acidic environment."

There are exceptions. "Tiny kids on formula a lot of times don't have the acid in their stomachs," making them more vulnerable to bacteria, says Dr. Lynnette Mazur, a professor of pediatrics at the University of Texas Medical School. Also, Forman and Mazur say that Pseudomonas can be a threat to people with cystic fibrosis.

The study, published last week in the journal Science, didn't examine the effects on people. And experts say without further detail, it's impossible to say what the bacteria could do to an infant or child who eats extraordinary amounts.

In any case, because of ordinary air pollution in snow, it's probably wise not to eat of lot of the stuff, pediatricians say. For parents in search of guidance, Mazur offers this: Licking a little snow off a glove is probably OK. "A meal of snow" is not.

Some parents say they are not going to worry about their kids eating snow that looks clean.

"My snow-eating concerns are generally more of the dirt-urine variety," says Kristin Lang, 37, of Maplewood, N.J., whose 2-year-old son Charlie has swallowed his share of snow.

"When I heard bacteria, at first I went 'eew,'" says Tricia Sweeney, a mother of three in Cornwall-on-Hudson, N.Y. But as long as the kids eat snow as it's falling, "I think it's OK. I tell them not to eat it if it's on the ground."