Portable pools have become common summertime backyard fixtures. Available in a variety of configurations (from shallow, plastic wading pools to family-size inflatable contraptions), they can be bought at toy stores and home-improvement stores. They typically don’t require the kind of investment or maintenance that in-ground pools require.

And somehow, by virtue of their relatively low cost and ease of ownership, it seems people tend not to take them quite as seriously as they should.

A sobering report published online this morning in the journal Pediatrics should be required reading for anyone who owns, or is considering purchasing, a portable pool. The report, the first to review pediatric deaths and non-fatal “submersion events” in portable pools, found that from 2001 to 2009, 209 children under 12 died after becoming submerged in such pools. An additional 35 survived after having been submerged.

The vast majority — 94 percent — of the events took place among children under 5 (41 percent among 1-year-olds). Fifty-six percent of the children involved were boys. Thirty-two events took place in wading pools. And 73 percent took place in the child’s own back yard.

The data draw attention to the fact that it doesn’t take much water to cause a drowning: The water depth in the reported cases ranged from 1 inch to 4 feet.

One inch.

Though the records on which the report is based (from data compiled by the U.S. Consumer Product Safety Commission) were incomplete, the authors note, they still offer a glimpse at how these awful events transpire. Little children let themselves out of houses via doors left open or unlocked. They climb the pool ladder and get into the pool unsupervised. And nobody notices until it’s too late.

In some cases, children drowned while technically under adult supervision, slipping into trouble when the adult has run into the house to answer the phone, gone to the fence to chat with a neighbor or fallen asleep.

The report notes that people don’t tend to build fences around portable pools because fences cost way more than the pools themselves. They don’t tend to remove pool ladders because it’s a pain in the neck to do so. All kinds of seemingly benign circumstances can lead to a child’s drowning.

To prevent that, the report calls for public education initiatives that would help parents understand the dangers of portable pools and teach them basic safety techniques to help keep children from harm. Manufacturers should consider ways to make their portable pools and related products (ladders, safety covers) safer for consumers, the report suggests.

Obviously, the number-one precaution is to keep a vigilant eye on your child all the time. But who among us hasn’t fallen short in that area at some point in our parenting career?

Still, putting that pool in your yard, even if it’s just a tiny wading pool, demands a whole new level of commitment to supervising your child. (The same is true if a neighbor puts up a portable pool; nearly a quarter of the drownings reported in Pediatrics took place among children who’d left their own yard and wandered into another.)

Do you have a wading pool or other above-ground pool? What steps do you take to keep your children — and your neighbors’ kids — safe around it?