There is a lack of confident knowledge about the properties and usefulness of sunblock. Sunblock is intended to protect the skin from ultra violet electromagnetic wavelengths. This is a portion electromagnetic spectrum which is invisible to human sight. There are several categories of ultraviolet light. There is ultra violet A, B, and C. Each of them have different affects on the body and highly dangerous.
Ultraviolet A (UVA) waves are between 320 nm and 400 nm in length and damage the collagen in the skin, causing it to lose elasticity and begin to wrinkle. Ultraviolet B (UVB) waves are between 290 nm and 320nm in length and cause the skin to tan and burn by stimulating the melanocyte cell. In addition, it is known to have a carcinogenic effect by “a process of direct photochemical damage to DNA from which gene mutations arise”1. As it is believed of now, ultraviolet C (UVC) is not as much of an issue because the ozone blocks a majority of these waves, but with the depletion of the ozone this will become more of an issue.
However, there is the problem which arises from avoiding sunlight. That is the deficiency of vitamin D, a essential component to nutrition which prevents helps prevent an assortment of dysfunctions. It is under my impression that the trade-off for skin cancer for a deficiency in vitamin D is well worth it, especially since a proper diet can replenish this lack of vitamin D.
So, in order to protect yourself from the adverse effects of being exposed to the sun, you must use sunblock. Gasp! Unfortunately a majority of retail stores sell chemical based sunblocks. A chemical based sun block defers the energy of the electromagnetic waves by absorbing the energy. Essentially it is photolabile and reacts with your skin. This is as bad as it sounds and it too is believed to be dangerous to your health. Which is why people are ranting and raving about physical sunblocks, which reflect a large portion of the energy, absorb less, and are not photo reactive with the skin.
There are two kings: zinc oxide and titanium dioxide. Also there is Mexoryl, which was recently approved by the FDA, by L’Oreal, but it only blocks UVA waves and needs help from chemical based sunblocks to block UVB waves. Not to mention, the products from L’Oreal are equal in price or far more expensive, depending on what product you choose. As for zinc oxide, it is by far the best sun blocking agent one can find in the market today. It blocks wavelengths between 290 nm and 380 nm, which is nearly the entire UVA and UVB spectrum. In comparison to titanium dioxide, “microfine zinc oxide is less white than titanium dioxide at all concentrations” due to having a lower refractive index2. This appeals to the public interest for consumers would like to have their sunblock invisible. Actually titanium dioxide and zinc oxide are very comparable in protection, but its higher ability to conduct and increased whiteness leaves it less desirable when compared to zinc oxide. Refer to Microfine Zinc Oxide is a Superior Sunscreen Ingredient to Microfine Titanium Dioxide Sheldon R. Pinnell for a more complete comparison.
The only negative aspect that would concern most consumers about using zinc or titanium is that it is a heavy metal and may clog pores, thus resulting in a breakout. However, as you may or may not know, zinc oxide is a cream treatment for acne and it might actually benefit your skin. This differs from person to person and it is recommended that you find the perfect product for yourself. For me, it was Sensitive Australian Sunscreen by Blue Lizard. Boasting a 10% concentration of zinc oxide and 5% for titanium dioxide. It is a highly reliable product and does not hit the wallet to hard. I have found it at every CVS for about nine dollars.
Other recommend products: Solar RX from Keys Soap (very expensive), UV Sport from UV Natural (less expensive than Solar RX, but just as good), baby version from Blue Lizard (same as sensitive version).
Overall summary
Zinc oxide: best standalone protection, may/may not clog pores, and less white than titanium.
Titanium dioxide: second standalone protection, may/may not clog pores, believed to be reactive like chemical sunblocks, and healthier than most shelf products.
Mexoryl: only blocks UVA waves, paired with chemical sunblocks, and typically expensive.
Articles
1: Department of Dermatology, University Medical Center, Utrecht, The Netherlands.
<http://www.ncbi.nlm.nih.gov/pubmed/10907526>
2: Sheldon R. Pinnell MD, David Fairhurst PhD, Robert Gillies PhD, Mark A. Mitchnick MD, Nikiforos Kollias MD (2000) Microfine Zinc Oxide is a Superior Sunscreen Ingredient to Microfine Titanium Dioxide
Dermatologic Surgery 26 (4) , 309–314 doi:10.1046/j.1524-4725.2000.99237.x
This is a great article. I never think of zinc and titanium as more than a nose guard. Thanks for bringing it to my attention. Keep up the good blogging and good luck with the bunnies.