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Author Topic: Are mineral sunscreens effective?  (Read 6029 times)

Mary Hill

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Are mineral sunscreens effective?
« on: 06/06/2009 19:30:02 »
Mary Hill  asked the Naked Scientists:
   
Dear Chris,

Please would you advise me as to whether natural mineral sunscreens using titanium dioxide and zinc oxide to reflect UV rays away from the skin are as effective as chemical sunscreens?

Your programme is absolutely fantastic!

Many thanks

Mary Hill

What do you think?


 

Offline Bored chemist

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Are mineral sunscreens effective?
« Reply #1 on: 06/06/2009 19:43:28 »
TiO2 and ZnO are both chemicals.
 

Offline Chemistry4me

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Offline Yomi

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Are mineral sunscreens effective?
« Reply #3 on: 08/06/2009 07:18:52 »
he titanium dioxide and zinc oxide used in Mexitan is micronized, with a coated variable particle size in the range of 100-200nm. (Nanoparticles are considered to be less than 100nm in size). This allows our sunscreen lotions to be more cosmetically appealing compared to coarser particles. The protection is less visible, yet remains on the skin's surface.
 

Offline Raghavendra

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Are mineral sunscreens effective?
« Reply #4 on: 08/06/2009 07:53:54 »
adsorption... causes the effect
 

Offline Yomi

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Are mineral sunscreens effective?
« Reply #5 on: 08/06/2009 07:55:39 »
they save us from getting skin cancer so adsorption is not to be worried.......
 

Offline Raghavendra

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Are mineral sunscreens effective?
« Reply #6 on: 08/06/2009 09:02:22 »
 But the DNA & RNA depend on that....
 

Offline Yomi

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Are mineral sunscreens effective?
« Reply #7 on: 08/06/2009 09:04:24 »
depends on what please specify........
 

Offline Kevan Gelling

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Are mineral sunscreens effective?
« Reply #8 on: 08/07/2009 12:50:59 »
Is there any evidence that sunscreens are effective at preventing skin cancer?

There's this ambiguous statement from Cancer Research UK which suggests that they don't have any evidence:
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Some researchers have failed to show that using sunscreens can lower the risk of melanoma.

Whereas here's quote from Wikipedia with 6 citations that suggest sunscreens don't prevent skin cancer:
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It has been found that sunscreen use is correlated with malignant melanoma

 

Offline Kevan Gelling

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Are mineral sunscreens effective?
« Reply #9 on: 08/07/2009 14:10:55 »
Here is more background to the sunscreen debate - from Wikipedia.

It would appear that sunscreen did not protect against UVA light.  Modern sunscreens do (look for the 5 stars UVA circle on the back of the bottle).
 

Offline mad scientist

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Are mineral sunscreens effective?
« Reply #10 on: 10/07/2009 13:13:55 »
Actually the answer is depends but in general the inorganic sunscreens are more effective as they block or adsorb both UV A and UV B wavelengths.
Most chemicals sunscreens up until a few years ago only protected against UV B radiation until the FDA approved Parsol 1789 or avobenzone.
Plus if you are a fisherman like me you don't want the chemical sunscreens on your hands/equipment. The ethylhexyl methoxy cinnimate is an effective repellant for fish and geese and other animals.
Did you know that sunscreens are regulated as an over the counter drug?
 

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Are mineral sunscreens effective?
« Reply #10 on: 10/07/2009 13:13:55 »

 

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