We’re now deep into summer, which means the lucky among us are deep into their swimming pools on a regular basis. Hitting the backyard to cool down and relax in the calming waters of your own pool is indeed a luxury, but with all the chemicals needed to keep the water clean, can it also be a hazard?

Chlorine, the cleaning agent of choice for the vast majority of pool owners, is, after all, a dangerous element. In certain uses, chlorine can pose a major environmental hazard, such as in the production of PVC.

But does the form of chlorine in pools, and the relatively low levels used, present a real risk? The World Health Organization gives a qualified “no.”

WHO explains it’s not chlorine itself that’s a health risk but the chemicals produced when chlorine interacts with other substances in pool water. WHO acknowledges these risks, but concludes, “the risks from exposure to chlorination by-products in reasonably well managed swimming pools would be considered to be small and must be set against the benefits of aerobic exercise and the risks of infectious disease in the absence of disinfection.”

The key phrase there would be “reasonably well managed.” There are some health horror stories as a result of mismanaged pools, but what about when you’re doing everything right with your pool upkeep?

Pool industry group The Association of Pool & Spa Professionals recommends daily testing to ensure a minimum level of 1 ppm of free chlorine – the specific form that acts as the cleanser – in your pool, up to the EPA-mandated maximum of 4 ppm. So optimally you should shoot for around 2 ppm.

However, there are studies indicating even these levels may be hazardous. Research published in 2003 in Occupational and Environmental Medicine shows a link between regular use of indoor pools and asthma, and a 2004 study in the American College of Sports Medicine shows a link between respiratory problems in trained swimmers and chlorine, even at levels as low as 1 ppm.

So how does the EPA reach its 4 ppm recommendation? Remember, it’s not the free chlorine itself, but the chlorine’s interaction with other stuff in a pool – anything from tree litter to splashed-off makeup to urine – that creates the dangerous chemicals. So the APSP sticks by its numbers, and stresses the importance of overall pool procedures, including maintaining proper pH balance, keeping pools clear of debris, properly venting indoor pools, staying out of the water when sick, taking frequent bathroom breaks, showering before swimming, and, of course, not swallowing pool water (good luck with that last one).

But beyond the possible health risks, some people simply don’t like the feel of chlorine in their hair and on their skin, not to mention the smell. There are options:

Ozone generators – These machines release ozone into the water to kill microorganisms, and requires you to use much smaller doses of chlorine. But ozone has its own problems, according to the EPA.

Ion generators – Copper and silver are used to clean out the bad stuff.

Organic cleansing – Probably the most extreme alternative, this system pumps water through rocks and plants to clean your “natural swimming pool.”

So, pool-owners, let us know: How much of a stickler are you on keeping your pool clean?