The fact that they’re small, cheap, and temporary doesn’t make them any less deadly. A new study out today from the American Academy of Pediatrics published in the Journal of Pediatrics finds that portable backyard pools are “a significant risk” to children younger than 5. The inflatable pools have claimed 209 children’s lives since 2001; 94 percent of those were children under 5.

We’ve written about the dangers of inflatable pools before, noting that the inexpensive, temporary character of this style of pool makes it unlikely that the proper layers of protection will be installed to keep kids safe. But that’s a bad call; last year, industry estimates put sales at 30,000 to 40,000 annually. That’s a boatload of potential tragedy for kids, especially when you factor in that in the U.S. accidental drowning is the second leading cause of injury-related death for children 1 to 14.

The pliable sides on inflatable pools sag under the weight of a child and can allow a head-heavy toddler to topple in. And since they hold thousands of gallons of water, the pools won’t be emptied after each use. That can leave an attractive backyard hazard up all summer long. Although constant adult supervision is the best protection against drowning, parents can’t be vigilant 24/7. And despite how vigilant you might be with your own children in and around the pool, a wandering neighborhood child is all too vulnerable to a silent, tragic death.

No single precaution can keep kids safe. A piece of equipment this dangerous requires multiple layers of protection to ensure it’s safe. Every pool should be surrounded by a non-climbable fence, at least 4 feet high, with a self-latching, self-closing, locking gate. Any door from the house to the pool should have an alarm on it. Pools should also have an alarm that sounds at the pool as well as in the house should someone fall in, and a safety cover. We are not aware of an adequate pool alarm or safety cover designed for inflatable pools.

We think that it’s highly unlikely that consumers will pay at least 10 times the cost of the pool for necessary layers of protection. Consumer Reports continues to urge consumers not to buy inflatable pools.

For more on this issue, see this segment from this morning’s NBC Today Show.