radiation

Ultraviolet radiation and myopia

Ultraviolet radiation and myopia 2

I feel like writing another article about the possible benefits of something we’ve all heard is bad for us. Ultraviolet radiation (UV) sounds bad. Maybe because of the word radiation (not a bad word though) and then maybe all the news warning us about UV exposure. I’ve had many sunburns and believe it’s contributed to a couple of skin problems I’ve had so I believe the redness and pain associated with sunburns is a pretty obvious sign of too much sun. As a kid in the 70’s I remember putting zinc oxide on my nose. It was a thick bright white cream that definitely was noticeable. I wish I had a picture of that when I was sitting on the lifeguard stand watching all the other kids get their UV (and chlorine) exposure at the pool.

You’ve got to wonder though how our species ever survived with that constant stream of the suns rays just bearing down on us all the time. Scientists have divided up that UV band of radiation into 3 forms….A, B and C. A is the least harmful and C is the worst but C doesn’t even reach us because the atmosphere’s ozone absorbs that band. Why did we even call it UV-C if it doesn’t reach us? We can create UV-C ourselves through welding however. See the chart at the end showing the UV ranges.

One huge benefit of UV exposure is our body uses it to produce vitamin D. We can also get vitamin D from other sources and you’ll find plenty of foods supplemented with vitamin D. That just makes me wonder why all the news about vitamin D deficiency. I have read that too much UV-B exposure can actually destroy vitamin D production but that article I read didn’t say if that was 1% destroyed or 100%. That’s what bothers me about some of the information we get unless you dig further in the research. And this is where I think some organizations have gone too far with their warnings. They make the sun sound like it’s horrible! Too much of anything isn’t good for you but articles talking about avoiding UV just seem wrong. Life wouldn’t exist without it. Too much vitamin D supplementation isn’t good either….that’s toxic. Do they talk about that? Rarely. Instead of warnings, we should talk about moderation.

Here’s another thing I’ve been interested in regarding UV radiation. Most of the contact lenses I prescribe have an FDA approved UV blocking agent in the lenses. I don’t know when that all started. Since I don’t wear contact lenses and neither do most other people, will those that wear these UV filtering contact lenses be better off than the rest of us? And then there are glasses that have UV protecting effects. Will people that wear glasses be better off when the results of UV accumulation over a lifetime are more obvious regarding diseases attributed to UV exposure? I do wear sunglasses outside….sometimes. Most sunglasses, even cheap ones, block practically all UV radiation and our car windshields block that as well. I’d like to know how I can measure my lifetime UV exposure. Have I exceeded it? How can I possibly know if I have a little left over so I can go play outside?

But there’s one more thing that is interesting about the possible benefits of UV exposure…in children. It’s thought that the outdoors might provide some protective effects against myopia development. That means some very credible studies are finding the sun is good for kids. There’s even at least one study that shows that UV exposure may provide a certain protective effect against myopia. Instead of “protective” can I say benefit?

I say get outside and enjoy whatever weather you’ve got. Put down the ipads and back off the consoles and let me put up a permanent basketball goal at my house! The kids need to be outside more!

Here’s a study about UV and myopia.

http://www.ncbi.nlm.nih.gov/pubmed/22669720

 

UV graphic

UV graphic

 

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Zealand to New Zealand, Rutherford to protons

Zealand to New Zealand, Rutherford to protons 0

If there’s a New Zealand there’s got to be an old one. We keep a lot of old things around, even countries and cities. A little later in this post I’m going to talk about a New Zealander named Ernest Rutherford. He did an amazing experiment. His “microscope” was as phenomenal as the LHC….Large Hadron Collider. And to me my little light microscope is pretty amazing but worlds apart from subatomic particle microscopes.

Back to part of the post title, Zealand. This is where I started getting confused. But let me try to explain this. Zealand is the largest island in Denmark. It’s Danish. Not Dutch. If you are from the Netherlands, you’re referred to as Dutch (apparently Dutch people are really a native ethnic group from the Netherlands). Let’s not go any further because I’m sure I’ll probably say something that isn’t correct (right). But there are some very famous Dutch people…very famous….van Gogh is probably someone practically everyone knows about.

On to Ernest Rutherford who is neither Dutch nor Dane. He was born in New Zealand however (a Kiwi 🙂 ). And what his microscope did (in the UK) was find that the center of the atom (we call the nucleus) had a positive charge. If you remember anything about an atom, you probably remember that electrons carry a negative charge and the protons (in the nucleus) have a positive charge. It makes you wonder how over 100 years ago someone figured that out. To me it just doesn’t seem like someone without an iphone could possibly have figured that out. I know that sounded stupid but it’s just amazing what science has known for a long time. You know where we stand…on the shoulders…..

A tad bit more about his “microscope.” There is no way to see an atom with ordinary light. An atom is too small to see with visible wavelengths. He sent alpha particles (radium decayed positively charged helium particles that had no electrons) through a thin sheet of gold and measured what came out on the other side. He also measured what was reflected and didn’t go through. That was his microscope. He expected all the alpha particles would go through the other side but not all did. Some bounced back. Remember, positive repels positive. But there is a large empty space in an atom so most particles went through. And just remember, any ordinary light hitting a thin sheet of gold doesn’t go through the gold. It takes a way smaller particle to do that.

So, a patient I had some years ago had a tumor in his eye. I found it and took a picture of it. Showed it to the patient.  He ended up seeing a doctor somewhere in California for proton beam radiation treatment. Yep, thanks to all the scientific discoveries, protons were eventually harnessed for our benefit. And thanks to the Zealands, new and old. May they keep adding on to our rich wealth of history and discovery.

Here’s a fun website that compares the various sizes of things in our universe…big to small. http://htwins.net/scale2/

 

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