One child drowns every five days in a portable pool during warm weather months, according to a new U.S. study.

The study by the Center for Inquiry Research and Policy investigated incidents in portable pools, from small wading pools that are no deeper than 18 inches to inflatable pools and other soft-sided pools that can be deep as 4 feet.

The study used the data compiled by the U.S. Consumer Product Safety Commission for cases of drowning or near-drowning in these types of pools reported to the commission.

The statistics showed 209 children below 12 years of age died in portable pools from 2001 to 2009. Twenty-five children almost drowned during the same period. Ninety-four percent of these events involved children younger than five years. Fifty six per cent were boys and 81 per cent of the incidents happened during the summer months.

The results are comparable to findings for in-ground pools.

The study suggested having adequate safety devices such as a ladder locker; fencing and pool alarms can prevent these incidents. However, these options are too expensive for many families to afford it. Also proper education and training on water safety could prevent these accidents as well.

It was also suggested that when parents are outside and cannot supervise their children, parents should make sure the pool is emptied.

Study author Dr. Gary Smith, head CIRP at Nationwide Children's Hospital in Columbus, Ohio warned of the quickness with which drownings take place.

The problem with submersion underwater is it's very quick...and once (a kid's) heart and breathing stops it's very difficult to revive them, he told Reuters Health. You don't get a second chance.

He also said parents must know that pools can bring serious risk to their children.

The study was published in the July issue of Pediatrics.