So before the hot sunshine comes, have a read of 7 questions about sunscreen.
1. What
is the history of sunscreen?
The ancient
Egyptians considered lighter skin to be attractive, making potions to prevent
sunburn. Some of the ingredients they used are in our sunscreens today.
A pharmacist
in South Africa produced the first sunburn cream as we know it, in the early
1930’s.
The founder
of L’Oreal refined this preparation, making the first sunscreen in 1936.
In 1938 an
Austrian Piz Buin chemist came up with the sun protective factor, SPF. SPF is
“a standard for measuring the effectiveness of sunscreen when applied at an
even rate of 2milligrams per square centimeter.” His original cream had a SPF
of 2.
After more
experimenting, in the 1980’s, the company Coppertone developed their first
UVA/UVB sunscreen.
Research
continues with ideas of developing a sunscreen pill…!!!?
2. How
does sunscreen work and what are the benefits of using one?
A sunscreen is
a protective layer which has inorganic chemicals that reflect the sunlight, and
organic molecules that absorb the UV rays releasing it as heat, hence
preventing or minimizing the amount of UV rays getting through to the skin.
UV rays
consist of UVA and UVB
– UVB are shorter in wavelength so
don’t penetrate deeply into the skin. These rays are the main cause of sunburn
and skin cancer and cause damage to DNA. The SPF factor in a sunscreen only protects
a person from the UVB rays.
– UVA are longer in wavelength,
penetrating to deeper levels of the skin, they are linked to the cause
premature aging of the skin. Only sunscreens that carry the words “broad
spectrum” will protect from UVA rays.
Australian
research at Queensland Institute of Medical Research in Brisbane in 2013, found
regular sunscreen application helped to counter the premature aging of skin.
Researchers however did say that as well as the lack of sunscreen use, there
are other factors that contribute to premature skin aging and skin cancer, such
as smoking, sun exposure history, skin colour and wearing sun protective
clothing including hats – these conditions are not prevented by the use of
sunscreen alone.
3. Are
there any concerns about sunscreens?
Babies of 6
months and younger should not use sunscreen at all because of its chemical
ingredients. It is best to keep babies in this age group in the shade or indoors
during the hottest time of the day, 10am – 4pm.
“One of the main constituents of sunscreen is
the ZnO particles. ZnO nanoparticles are sought out for UV-filter applications
thanks to their inherent optoelectronic properties and are, therefore, broadly
used today in cosmetics and polymers. Preliminary toxicological data, however,
point out that they can induce significant DNA damage and genotoxicity due to
their Zn2+ ion leaching. It has become important for the nanotechnology
industry, to devise scalable, safer-by-design approaches to minimize the ZnO
nanoparticle dissolution and toxicity without altering their desired
optoelectronic properties.” “In our center we
developed a safer formulation concept to mitigate toxicity by encapsulating the
materials in a thin layer of Silica.” Feb 2014.
4. What
is the correct way to put sunscreen on?
* Apply
before going outside
* Some say
use a shot glass full of sunscreen as a quantity guide to cover your body,
however bodies are different in size. Professor Leffell of Yale School of
Medicine says, “use enough to evenly cover the skin and massage it in, and be
systematic about it. There’s no such thing as using too much.”
* Reapply 2
hourly, more often after swimming or heavy sweating. The skin literally uses it
up. Apply and wait a few minutes to give time to be absorbed before swimming,
otherwise you simply wash it all off.
5. What
do different SPF scores mean?
“Products with a higher SPF
allow fewer of the photons that produce sunburn to strike the skin. In simple
terms, you can view an SPF 10 sunscreen as allowing 10 out of every 100 photons
to reach the skin and an SPF 20 product as allowing only 5 out of every 100
photons to reach the skin.” http://www.scientificamerican.com/article/how-does-sunscreen-protec/
A product with SPF 30+ will block out 96% of sunburn from UVB rays.
A product with SPF 60 or more will only very slightly increase that
protection. There is no product that can give 100% protection.
Specialists therefore warn of the need to never trust in sunscreen
alone, but add wearing a wide brimmed hat, sunglasses, tightly woven fabrics or
clothing that absorbs UVA and UVB rays and avoid being out in direct sun for
long from 10am – 4pm. Stay in the shade.
Moisturizers and makeup foundations often have SPF in them. Foundation
with SPF does not give sufficient protection as it fades through the day and
when applying you put less quantity of foundation on your face than the
quantity of sunscreen you would apply.
Moisturizers with SPF however do give effective sun protection.
6. Are there benefits from being in the sun?
In just a few decades we have gone from promoting summer sun worship
to sun dread over the summertime.
But sun on the skin does have benefits – it relaxes,
eases off depression and mind anxiety. It lifts our emotions. Going out into
the sun promotes outdoor sport, real play for children and gardening, which are
all essential contributors for our wellbeing.
It is questionable if the level of vitamin D deprived
people today was as high a few decades ago. Being in the sun is a natural and
the best way to receive vitamin D. Getting 10 to 15 minutes of sunlight on your
face, arms, back, or legs without sunscreen a few times a week is enough to
generate your body’s vitamin D needs for a week.
7. Do sunscreens last forever?
The active ingredients in sunscreens do deteriorate
over time, becoming less effective, so check the expiry dates of the sunscreens
in you cupboard.
To be available and handy for use sunscreens are often
stored in the car glove box or boot all year round. This exposes them to
extreme high temperatures, which also may result in their effectiveness being
compromised.
Cathy
