Phoenix Pools: Are Mineral Sunscreens a Toxic Mix?
By Franklin Everett ShawThe Arizona sun beats down with relentless intensity, especially in Phoenix. We all know the drill: sunscreen is non-negotiable. But what kind? And how does it play with the chlorine in the countless public pools that offer respite from the heat? The answer isn’t as simple as grabbing the first bottle you see at Fry’s.
Mineral sunscreens, with their active ingredients of zinc oxide and titanium dioxide, are often touted as the “reef-safe” and “gentle” alternative to chemical sunscreens. But let’s dive deeper, specifically for those of us cooling off at the Eldorado Aquatic Center or the Washington Park Pool.
First, let’s address the chlorine question. Chlorine, used to disinfect pool water, can react with organic compounds, including some ingredients found in sunscreens. This reaction can create disinfection byproducts (DBPs), some of which are potentially harmful. Mineral sunscreens, being inorganic, are less likely to react with chlorine compared to their chemical counterparts. However, the other ingredients in mineral sunscreens – the emollients, stabilizers, and fragrances – can still react.
Consider this: a study published in Environmental Science & Technology found that certain sunscreen ingredients, when exposed to chlorine, can form DBPs like chloroform. While the study didn’t focus solely on mineral sunscreens, it highlights the importance of considering the entire formulation, not just the active ingredients.
So, what’s a Phoenician to do? Here’s a practical guide:
Read the Label, Carefully: Don’t just look for “zinc oxide” or “titanium dioxide.” Scrutinize the inactive ingredients. Avoid sunscreens with high concentrations of fragrances, oils, and polymers. Look for shorter ingredient lists, which generally indicate fewer potential reactants. Think of it like reading the ingredients on a Sonoran hot dog – you want to know everything that’s going in!
Particle Size Matters: Mineral sunscreens come in two main forms: nano and non-nano. Nano-sized particles are smaller and can be more easily absorbed into the skin. While some concerns exist about the potential for nano-particles to penetrate the skin and cause harm, the consensus is that the risk is low, especially compared to the risk of sun damage. However, from an environmental perspective, non-nano particles are preferable. They are less likely to pass through filtration systems and accumulate in the pool water. Look for sunscreens that explicitly state “non-nano zinc oxide” or “non-nano titanium dioxide.”
Application is Key: This is where most people fail. Slathering on a thin layer right before jumping into the pool is not sufficient. Apply your mineral sunscreen at least 15-20 minutes before sun exposure. This allows the sunscreen to properly bind to your skin. Use a generous amount – about a shot glass full for your entire body. Reapply every two hours, or immediately after swimming or sweating. Think of it as building a protective shield against the Arizona sun, not just a light dusting.
Choose Water-Resistant Formulas: Look for sunscreens labeled “water-resistant” or “very water-resistant.” These formulas are designed to stay on your skin longer, even when submerged in water. However, remember that “water-resistant” doesn’t mean “waterproof.” Reapplication is still crucial.
Shower Before Swimming: This is a simple but often overlooked step. Showering before entering the pool removes excess oils, lotions, and other substances that can react with chlorine. This not only helps protect the pool water but also allows the sunscreen to adhere better to your skin.
Consider Sun Protective Clothing: Sunscreen is just one tool in your sun protection arsenal. Wearing a wide-brimmed hat, sunglasses, and sun-protective clothing (UPF-rated) can significantly reduce your reliance on sunscreen. This is especially important for children, whose skin is more sensitive to the sun.
Be Mindful of the Pool Environment: Some public pools in Phoenix, like those managed by the City of Scottsdale, have specific regulations regarding sunscreen use. Check the pool’s website or ask a lifeguard about any restrictions or recommendations.
The "Rub Test": Mineral sunscreens are notorious for leaving a white cast on the skin. This is because the mineral particles are designed to sit on top of the skin, rather than being absorbed. To minimize the white cast, rub the sunscreen in thoroughly. Look for tinted mineral sunscreens, which contain pigments that help to blend the sunscreen into your skin tone.
Don’t Forget the Sensitive Areas: Pay special attention to areas that are often overlooked, such as your ears, nose, lips, and the back of your neck. Use a lip balm with SPF to protect your lips from sun damage.
Consider the Source: Not all mineral sunscreens are created equal. Some brands use higher-quality ingredients and more effective formulations than others. Look for sunscreens that have been tested and approved by reputable organizations, such as the Environmental Working Group (EWG).
A common pitfall is assuming that all mineral sunscreens are inherently safe for pool environments. The truth is, the entire formulation matters. Another mistake is under-application. People often apply too little sunscreen, which significantly reduces its effectiveness. Finally, neglecting to reapply sunscreen after swimming or sweating is a recipe for sunburn.
Let’s be real: finding the perfect mineral sunscreen for Phoenix pool days is a bit of a Goldilocks situation. It needs to be effective, water-resistant, non-reactive with chlorine, and environmentally conscious. But by following these guidelines, you can make informed choices that protect your skin, the pool water, and the environment. So, go ahead, enjoy that dip in the pool at the Papago Park pool, but do it responsibly. Your skin (and the pool) will thank you.