5 Side Effects of Swimming in a Pool With Too Much Chlorine
Pool season isn't complete without the scent of chlorine in the air. But does smelling the chemical mean the pool is overchlorinated? And if so, what happens if you're overexposed to the disinfectant?
Here are the signs and symptoms of too much chlorine in a pool, and how you can test the waters (literally) to stay safe.
What Is Chlorine and What Does It Do?
Chlorine is a chemical element added to pools to kill off bacteria like Salmonella and E. coli, parasites like Giardia, and viruses that cause diarrhea and swimmer's ear. It can kill most germs within a few minutes. Ultimately, it's essential to have some level of chlorine in pools to keep swimmers healthy and safe.
While chlorine has a scent, the strong smell you notice isn't from the chlorine itself. "What you're smelling is chloramine, which is a reaction between chlorine and amines. Amines are compounds that can occur in sweat, urine, and stool. This reaction kills bacteria and causes that chlorine smell," says Brad Uren, MD, an associate professor of emergency medicine at the University of Michigan Medical School in Ann Arbor.
5 Ways Too Much Chlorine in the Pool Can Affect Health
Too much chlorine in a pool can cause several health problems. These include:
1. Irritated Eyes
Chloramine is heavier than air, so it hangs at the pool's surface, Dr. Uren says. If it gets into your eyes, it can cause stinging and irritation.
Chlorine can also wash away the tear film that coats the surface of your eyes and keeps them moist and clear. This reduction of tear film leaves the eyes itchy, watery, and red.
2. Coughing
Chlorine and chloramine gas are both irritating to the respiratory system (the lungs, nose, throat, and airways), Uren says. As a result, you may experience tracheobronchitis, or “chlorine cough,” from unbalanced chlorine in swimming pools. Side effects include coughing, chest tightness, wheezing, and a burning sensation in the throat.
People who spend more time in pools, such as competitive swimmers, and those with asthma may be more likely to experience chlorine cough.
3. Dry Skin, Hair, and Nails
In a properly maintained pool, a brief swim won't harm your skin, says Channa Ovits, MD, a board-certified dermatologist at Summit Health in White Plains, New York. However, if there's too much chlorine in the pool, she says you may notice dry skin and hair, along with weakened nails.
But even if your pool has a safe chlorine level, you may still experience side effects if you swim frequently. "Those who swim often and for extended periods can have the chlorine strip the oils from their skin and hair and get some dryness and irritation, as well as brittle hair," Dr. Ovits says.
4. Chlorine Poisoning
High chlorine levels in pools come with a risk of chlorine poisoning if someone swallows or inhales chlorine.
Symptoms of overexposure to chlorine include:
Blurred vision
Red and blistered skin
Burning in the nose, throat, and eyes
Coughing and difficulty breathing
Nausea or vomiting
Getting to fresh air and rinsing your eyes (if affected) with plain water for 10 to 15 minutes can help, but see a doctor if symptoms persist or get worse.
5. Skin Sensitivity
Chlorine is already irritating to the skin, but some people are especially sensitive. If you're hypersensitive, chlorine can cause your skin to become red, itchy, and painful. You may develop a lesion (an area of the skin that appears different from surrounding skin), rash, or hives (itchy bumps).
You may be more prone to skin issues if you frequently use the pool or if the pool has high chlorine levels.
How to Tell if There's Too Much Chlorine
The good old smell test is a great way to determine if a pool is safe. "It's totally normal to, say, walk into an indoor pool area and initially smell the faint scent of chlorine," Uren says.
But if the smell irritates your eyes and airways, it's a sign that the pool's chemicals are imbalanced.
How to Test for Safe Chlorine Levels
Use a DPD (N, N-diethyl-1,4-phenylenediamine sulfate) test kit to check the pH and chlorine level. A healthy pH range from 7.2 to 7.8 limits chlorine side effects while still adequately killing germs. A safe chlorine level in the pool should be at least 1 part per million (ppm) and not exceed 3 ppm, or the manufacturer's instructions.
If you don't know how much liquid chlorine to add to your pool, consider hiring a pool cleaning specialist to help you learn the ropes before maintaining it on your own. They can teach you the proper amount of chlorine needed and how to lower pool chlorine levels if they get too high.
Stay Safe in Home Pools
Pool chemical injuries often happen to children and teens at home when pool chemicals like chlorine are mishandled.
"Read the instructions, because there are many [chlorine] products. Powdered and liquid chlorine, for example, are both used differently," Uren says.
Storage also matters. For instance, keep chlorine in a well-ventilated place in case of a leak or spill, and store it on a tray to contain any leaks, he says. Similarly, open the package in a well-ventilated area. When pouring chlorine into a pool, follow directions carefully.
How to Prevent Side Effects From Chlorine: 5 Tips
Follow these tips to avoid chlorine's less-desirable side effects:
Stay out of the water if it's not safe. First and foremost, don't swim in a pool that's not properly maintained.
Rinse off before swimming. Take a one-minute rinse shower to remove excess sweat, lotion, and germs from your skin before entering a pool. In addition, get your hair wet. "Saturating the hair with fresh water is helpful, as the hair shaft will absorb less chlorinated water," Ovits says.
Wear protective gear. Swim caps can protect hair, while swim goggles can protect your eyes.
Use lubricating eye and ear drops. Lubricating eye drops can help alleviate any redness or itchiness you develop while swimming. And in addition to cleaning out your ears after swimming, using ear drops to help prevent the buildup of water — and subsequently, possible swimmer's ear — can be helpful.
Use sunscreen, and moisturize after swimming. Apply sunscreen before going into a pool, but save the moisturizer for later. Adding a layer of lotion under sunscreen can make sunscreen less effective, Ovits says, so moisturize once you’re done with outside time to help your skin rebuild its protective oil barrier.
The Takeaway
It's important to use enough chlorine in a pool to kill germs, but too much can cause uncomfortable and sometimes dangerous side effects.
A safe chlorine level is at least 1 part per million (ppm) and no more than 3 ppm, or what the manufacturer's instructions call for. To check the chlorine levels in a pool, use a DPD test kit.
The best way to avoid the unpleasant side effects of too much chlorine is to avoid swimming in unbalanced pools. Rinsing off before swimming, wearing protective gear, using eye and ear drops, and moisturizing after swimming can also help.
