My friend called me with a 911 from the sunscreen aisle at Whole Foods -- SO CONFUSING! Which one to chose? Which one is reef safe? Which one is safe for our kids? Which one will actually prevent a sunburn? We are going to take a sunscreen deep dive ... but if you want the summary, skip to the bottom.
So in Hawaii, kids are outside ALOT. Recess, walking to other buildings, gym, music, art, science, lunch, sports -- these activities can all be outside. They don't always keep their hats on, and forget about sunglasses on the little ones. What is a mom to do? More on that in a bit ...
The Sun and Skin Cancer
The doctor in me wants to prevent you from getting this: malignant melanoma, a deadly skin cancer. Some of the biggest risk factors are UV exposure (obviously), age, family history, genetics and fair skin. My kids are on the fairer side, so we definitely take sun precautions. It only takes 15 minutes before those UV rays start to do their damage.
Ugly, malignant melanoma
UV rays damage DNA, DNA damage can cause cells to proliferate out of control, which can cause some types of cancer. The sun produces UVA (long wave ultraviolet) and UVB (short wave ultraviolet). Both cause cancer. UVAs go deep into the dermis also causing darkening and aging. UVB causes sunburns and skin cancers by being almost completely absorbed by the epidermal top layer of the skin. Side note: tanning beds give off UVA, and dangerous UVCs come from welding torches! Check out an even deeper dive into UV rays here. Interestingly, SPF (sun protection factor) only applies to UVB.
Some easy things that you can do that don't involve sunscreen include:
staying out of the sun between 10am and 4pm
covering up with dry, tightly woven fabric
wearing sunglasses, rash guards, leggings
and finally ... sunscreen on sun exposed areas!
Sunscreen and Cancer Protection
So, we want to block UVB and UVA. We can do this 2 ways with sunscreen: with a chemical cream and with a physical barrier cream (like zinc oxide sunscreen: think white nose). Let's be clear: both chemical creams and physical barrier creams work to reduce the risk of skin cancer.
Chemical creams work by absorbing the UV rays that come into contact with the cream, and then releasing them as infrared rays. They don't all cover UVA and UVB together, and they aren't as stable as physical barriers, degrading more quickly. However, it turns out that a chemical like oxybenzone blocks both UVA and UVB rays. These sunscreens are cheap, easy to find, easy to apply, and I find that the kids like their feel.
Physical barrier creams containing zinc oxide and titanium dioxide do just that: create a physical barrier on the skin and actually reflect those UVA and UVB rays off the skin. Think chalky, white, highly reflective. And yes, titanium dioxide comes from titanium. They can feel kind of gritty and greasy, unlike the chemical barriers. Both zinc and titanium block both UVA and UVB but zinc blocks against the full UVA and UVB range (290 to 380 nm), whereas titanium misses the longer range UVA rays.
Sunscreen and its environmental impact
Hawaii's sunscreen ban which goes into effect January 1, 2021, and bans the sale or distribution of over-the-counter sunscreens containing oxybenzone and octinoxate. These chemical compounds have been linked in multiple studies to cause "bleaching, deformities, DNA damage and ultimately death in coral" when they get into the water (apparently the mechanism is through a viral infection of the coral aided by these chemicals). Bleaching doesn't mean sudden coral death, but it severely weakens and stresses coral and can lead to death. Death in coral means death of algae, which disrupts a delicate food chain where fish and marine life spawn and feed.
According to some research, damage to coral starts at 62 parts per trillion of oxybenzone. Apparently, beaches in Hawaii have oxybenzone levels higher than 700 parts per trillion early in the morning even before swimmers even arrive.
Coral bleaching according to NOAA: "when water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white"
The short list of chemicals found to bleach coral include:
What about zinc oxide and titanium dioxide? Do they harm the reef?
Nanotechnology grinds up zinc oxide into smaller nanoparticles (20 to 60nm), which are still effective in blocking UV rays, but feel aesthetically smoother and nicer on the skin. They then coalesce into particles 200 to 500 nm in size in lotions and creams.
Both zinc and titanium in a nanoparticulate form can cause coral bleaching, found in one recent study I read in the Smithsonian. Nanoparticles less than 35 nanometers in diameter can be toxic to corals, fish and other reef organisms and can enter the cells of organisms and bleach coral.
Check out this cool nerd-friendly post on nanoparticular zinc oxide from the German Federal Health Institute. Some people might be concerned that these small particles could enter the body at such small sizes, but apparently according to this site the zinc in nanoparticular size is safe for humans, and does not penetrate beyond the dead skin cell layers of the epidermis.
The good news is that NON-NANO (GREATER than 150 nm) zinc oxide and titanium dioxide is NOT harmful to coral reefs.
PHEW! Still with me?
(We do have controversy here though, which I think reflects the nature of changing habits when it comes to the environment, that is, it is never black and white. I have a friend who is a dermatologist, and she is really very worried about the possible uptick in sun-related cancers as pictured above. Skin cancer advocates are worried, but interestingly looking into this I found that the Skin Cancer Foundation since its inception has advocated sunscreen alongside other preventative measures too.)
So.....What Sunscreen Do I Buy?
Disclaimer: While I am a doctor, these tips are what I personally am doing for my family on Oahu...I encourage you to read and to do your research!
The short answer: zinc oxide or titanium dioxide, NON nano!
First, cover up and avoid the sun, so that the amount of sunscreen you use is less and you are using multiple strategies to protect yourself. Stay in the shade, stay out of peak sun. Try rash guards (there are many rated to SPF 50 now), hats, leggings (yes, these are a thing and come in crazy colors and patterns for example!) and sunglasses. Apply sunscreen to hands, face, feet.
Second, avoid anything with Oxybenzone, Butylparaben, Octinoxate or 4-Methylbenzylidine Camphor, which bleaches coral.
Third, opt for physical barrier sunscreen with zinc oxide or titanium dioxide. Remember that zinc oxide is going to protect you from more UV rays than titanium dioxide but titanium is still a pretty good bet. Really really rub it in, to get the white and grease absorbed into your skin. If it is still a little white, that's ok: you'll see where you missed!
Fourth, look for a zinc oxide or titanium dioxide that is NON-nano particular, greater than 150nm. (Smaller zinc and titanium particles also bleach coral).
Fifth, don't trust anyone: read your labels. "Reef safe" and organic and "eco-friendly" labels aren't regulated. Check the back of the container! Simpler formulas are better (even beeswax and plant based oils can be dangerous to coral).
This is a small collection of leftover sunscreen just laying around our kitchen. Only the locally made Mineral Sun Block on the left is zinc non-nano!
I'll update you after I investigate my local Whole Foods selection, but I know there are several locally made sunscreens...let's see which ones the kids tolerate!
Here is a product I found online from Stream2Sea that I was impressed with. Given the carbon footprint of shipping to our island, and the amount of sunscreen my kids will use, I probably won't be ordering it -- but I'll look for it!