It wasn’t so long ago that North Americans worshipped the sun in pursuit of perfect bronze skin.
It’s nice looking, but doesn’t weigh up against the well-known dangers of sun exposure.
Sun has ultraviolet rays which penetrate the atmosphere.
UVA and UVB both play roles in;
- premature skin-aging
- eye damage (including cataracts)
- skin cancers
UVA is long wave ultraviolet and UVB short wave ultraviolet. UVA penetrates deeper into the skin, and is more associated with aging skin, whereas UVB causes redness and sunburn. Both are associated with cancer. (UVA is used in tanning booths).
The tan is actually a response from UVA damage to the skin’s DNA.
The skin darkens to protect more damage.
- Seek shade, especially between 10:00 a.m. and 4:00 pm
- Avoid tanning and tanning booths
- While in the sun, wear a broad-rimmed sunhat, sunglasses (with uv block), loose tightly-woven clothing in bright or dark colours. Pastels and bleached cottons are less effective. Tightly-fitting clothing is more porous and lets more rays in.
When choosing a sunscreen, it should have an SPF (Sun Protection Factor) of at least 15 and should be broad spectrum, meaning it should say on the label that it blocks UVA and UVB.
SPF means the amount of time it would take for your skin to redden. So, if your skin normally turns red after 10 minutes in the sun, SPF 15 would give you 150 minutes of protection. SPF 15 blocks 93% of UVB rays, SPF 30 blocks 97% of UVB rays and SPF 50 blocks 98%. There is not a huge benefit to going over SPF 15.
All need to be re-applied after about 2 hours.
In order to be effective, it needs to be applied 30 minutes before sun exposure, every 2 hours thereafter and immediately after being in the water or sweating, regardless if it is labelled sweat-proof or water-proof. It should be applied thickly. Some studies are suggesting that chemical sunscreens can cause hormonal disruption and allergic reactions.
For people who find chemical sunscreens irritating, there are mineral sunscreens.
Most common is zinc oxide and titanium dioxide. Zinc is the ingredient found in diaper rash cream and is the only sun protection considered safe for babies. It was what lifeguards used to wear on their noses. It doesn’t entirely block the sun’s damage, but it does scatter the rays, making it a better block. It needs to be applied less frequently than chemical sunscreen.
To be more cosmetically attractive, these blocks now come in nano-particles, so that thick creamy look is gone.
There are some concerns that these non-particles get absorbed in to the bloodstream and deposited into vital organs.
Not a big deal in cold-water diving when pretty well the skin around your lips is the only exposure. For warm-water diving, considering unreliable water-proofing, the pain of getting sunscreen under your mask and your hands being all slippery, the simplest thing is to wear a skin under your shorty or over your swimsuit if you don’t need a shorty.
While on the boat or shore, seek shade before and after your dive.
Although undoubtedly beneficial to human well-being, sunscreens can harm aquatic life, the extent to which is currently under investigation.
• It’s estimated that between 4,000 and 8,000 metric tons of sunscreen washes of swimmers’ bodies annually.
• The nano-particles in zinc oxide and titanium dioxide never degrade, and mineral oils degrade slowly.
• Like any oil, they can be harmful to birds and aquatic life.
The nano-particles can harm;
• marine worm
Embryonic sea urchins exposed to nano-particles become more vulnerable to other toxins. They either did not develop into larvae, or appeared to develop normally, but could not eat, so they died.
Many “swim with the dolphins” or “snorkel with the rays” programs request that customers do not wear sunscreen.
This concern is more tangible because of the immediate effect of potential irritation of the skin and eyes.
The good news is that there are several companies doing research on truly biodegradable sunscreens.
Hopefully it won’t be long before protecting your skin does not mean harming our oceans.