Skin Cancer Scare

[d k]

In terms of being safe if you don't burn through your non-expensive non-UPF clothing, I do worry that what blocks the UV that causes sunburn may not necessarily block all the UV that contributes to skin cancer. Info is sometimes conflicting on the web, but looks like UVB causes sunburn and contributes to skin cancer. UVA is responsible for most tanning (which causes skin damage over time), and for damage deeper in the skin since it penetrates more deeply (is not blocked by glass). Some writings indicate that UVA is closely linked to melanoma.

So while long sleeved non-"UPF" clothing blocks some of the UV, not sure if it blocks both types equally. Tightly woven, loose fitting, bright or reflective cloth is supposedly better at protecting you than loosely woven/tight fitting items. And any way you look at it, any protection is better than the protection you can't afford and don't wear!

Sierra Trading Post is sometimes a great place to pick up sun-protective shirts and pants, by the way…

[jscott]

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[Roger Caffin]

> when leaving work, to drive for an hour just doesn't make sense.
Oh, I totally agree.

However, do you need sunblock inside a car? From PubMed at http://www.ncbi.nlm.nih.gov/pubmed/19614895

'Laminated glass totally blocked UVA radiation, while smooth ordinary glass transmitted the highest dose (74.3%). Greater thicknesses of glass implied less radiation transmitted, but without a significant difference. Green glass totally blocked UVA radiation, while blue glass transmitted the highest dose of radiation (56.8%). The presence of a sunlight control film totally blocked UVA radiation. All glasses totally blocked UVB radiation.'

Cars have laminated windscreens and windows, so they will block UVA. If they block UVA they will also block UVB and UVC. House windows are usually green glass.

> with my driver arm resting on the window,
Yeah, your arm will get sunburnt.

Cheers

[steven franchuk]

When I go hiking I wear nylon shirt, long pants (that can be converted to shorts), and a hat to protect the front, sides of my head. The hat rim is also wider on the back side so that it does a decent job covering the back side of my neck. I also wear sunglasses. bue sure your sun glasses do block UV (not all cheep or expensive glasses do). Most of the time I don't use sun screen because dirt sticks to it, Sweat washes it off or into my eyes, or I don't apply enough. Over the years I found that just using sun sceen was almost a sure way to get a sun burn. I have found covering up to be far more effective.

I also carry a small amount of sun screen that blocks UVA and UVB rays for the occasional problem areas. On longer trips my hands can burned which I can address with sun screen or wear gloves. On hot days when I switch to shorts and then apply sun screen to my legs.

Unfortunately your body need some UV to make vitamin D. In the past our ancestors spent most of the day outside and most had enough vitamin D. Vitamin D is necessary for a healthy immune system. Today most of us spend most of the day inside and therefore most of us don't get enough UV and therefore are deficient in Vitamin D.

For years doctors have been telling people to use sunscreen to prevent skin Cancer. and the use of sun screen has gone up significantly over the last 40 years. Yet with the increased use of sun screens, skin cancer rates have continued to go up. A lot of people are asking why and some of the theories are:

1. Most Sunscreens don't block uVA and UVB rays. My doctors now recommend using sunscreens that block UVA and UVB.
2. Skin cancer may be a symptom of vitamin D deficiency. Doctors on occasion see the immune system rally and cure the cancer before the doctors have started the treatment. The theory is that most cancers are detected and cured by the immune system without us being aware of it. The worst cancers are the ones the um immune system can't fight which are the ones we notice.
3. that there might be other factors that might be just as important or more important than vitamin D and or UV.

[Justin Baker]

I am fortunate that I don't get sunburned easily. I worked an entire summer outside in 100+ heat wearing short sleeves and never once got sunburned. My body works up a tan really quickly.
I usually wear shorts, a t-shirt, and a mesh trucker hat (the only hat that will fit my head) with a bandana underneath protecting my neck. I find that my face and neck are the most sensitive areas. My legs and arms are usually pretty resilient to the sun, with my arms being more sensitive than my legs.
However, after reading this thread I am going to take the sun more seriously.

[Jeremy and Angela]

Thanks for the link Roger! The question of windows is a good one.

Cars have laminated windscreens and windows, so they will block UVA.
That often applies only to the windshield and not the side windows. I tried some quick digging, and it seems like you can get UV or laminated glass on some luxury models.

House windows are usually green glass.
Are you thinking green glass as in soda-lime glass? It looks from the details that they were testing different colors of tinted glass (clear, blue, yellow, green, wine).

[Roger Caffin]

> > Cars have laminated windscreens and windows, so they will block UVA.
> That often applies only to the windshield and not the side windows.
Um … I question that. At least here in Oz, ALL glass in cars must be safety-laminated in case of accidents. Can you imagine shards of razor-sharp glass flying around?

Green glass – yeah, I could be misreading there.

Cheers

[Dale Wambaugh]

Glass in general will block UV to some extent. Hasselblad once offered a lens made from quartz crystal for UV research as the glass lenses blocked what was being studied. Yes, the UV filters the guy in the photo store sold you are mostly bogus.

Side windows in cars are tempered glass as they get the stress of rolling up and down and slamming doors. They don't like point pressure and break into small pieces when struck with a sharp point. You can bang on a side glass pretty hard without breaking it. A machinist's automatic center punch will toast a side window in one stroke. There is one taped under the dash in my cars.

Windshields are laminated and have been made thinner over the years and manufacturing techniques have improved. Thinner is better for the foreheads of people who won't wear seat belts. The plastic layer adds to the UV filtering, along with tinting.

You can tell which side of the road this old trucker was driving on:

[Jeremy and Angela]

^^^ What Dale said.

There's a list here of some cars that use laminated glass in places beside the windshield:
http://www.epgaa.com/applications/index.asp

Something to note is that escape devices like a center punch that work on tempered safety glass won't work on laminated glass, a potential problem if one must break a window to escape the vehicle.

[jscott]

After reading Roger's post I Googled this question (again! I did a lot of research two years ago) and BAM: the first hit was a NY Times article. Research showed that 74% of cancerous melanomas on men were on the left side of the face/neck/ears/arms. Drivers. Statistics for women were less, but I have a theory. This is a cancer of long term sun exposure. (As an aside, let me stress that getting a "healthy" tan to keep from burning does nothing to protect from long term exposure; quite the opposite.) In our father's generation, men did the driving. (Well, in MY father's generation). Hence, the results.

Obviously just a theory.

In any case, google this question about whether car glass keeps you safe from uva/uvb and see for yourself. My searches suggest that you need to pay for special coatings for good protection.

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