Related: I found the old measure (burn time) much easier to use than the new UV index, and while having it standard across countries is good, it’s not straight forward to convert.
https://www.niwa.co.nz/our-services/online-services/uv-and-o...
Not sure what the health qualms are with lack of Vitamin D bit I'm certain I don't want to advocate in favour of potentially harming people as much as my girlfriend experienced.
Rickets and Osteomalacia are the big ones, I think. Both are a form of softening of the bones. Vitamin D apparently helps regulate the absorption and use of calcium, magnesium, and phosphate in the body.
My sunbathing policy is to go without sunscreen but only for 20-30 minutes daily around noon.
I think this must be cultural. Certainly in my experience in the United States, the lust is for tanned skin. There are even tanning salons, where one can lie down in a machine which floods one's skin with UV.
Now, I personally love fair skin, and have never understood why others seem to love a tan so much.
1 - https://www.bloomberg.com/features/2016-tanning-salon-indust...
1 - https://www.bloomberg.com/features/2016-tanning-salon-indust...
If most people work outside for a living, then the sign of wealth is that you don't have a tan. If most people work in offices, then the sign of wealth is that you have a tan, implying that you went on vacation or otherwise have the available leisure time.
When most people do manual labor, having impractically long fingernails demonstrates that you don't have to do that.
When most people have two or three sets of clothing, changing clothes several times a day demonstrates your wealth.
When most people eat a subsistence diet, being fat is demonstrating wealth. when most people eat fast food, being thin demonstrates your superior resources.
If most people need to pay attention to what they are wearing at their jobs, dressing in a way which signals that you don't have to pay attention is a status marker.
If everybody drives a car, picking an unusual vehicle can be a status marker. What's the difference between a Chevy Silverado 2-door and a Ford F-150 SVT Raptor? They demonstrate different spending priorities.
I burn in front of a monitor, I have fair skin because factor 50 and covering everything I can are simply required.
[1] https://www.cancer.org/cancer/skin-cancer/prevention-and-ear...
It's not particularly clearly worded but to me that seems to suggest that tanning increases melanin and that melanin helps prevent cancer regardless of whether your dark skin is natural or tanned.
For a fixed amount of sun exposure, spreading out the duration is better both to establish a tan and to allow more time for skin recovery. But there isn't really a case where tanning increases safety, because you get the tan via exposure.
It's like saying pilots who practice a lot are safer; for any given flight it might be true, but cumulative risk can only rise.
https://www.scientificamerican.com/article/fact-or-fiction-a...
You clearly get more than SPF 3 with a deep tan as you can spend 8 hours in direct sun without obvious problems. Without any tan you get a burn in under an hour suggesting ~SPF 10+.
> people who were previously were at lower risk of cancer due to their skin pigmentation/higher melanin
So think about it this way:
If you're genetically predisposed to having very dark skin, you will be able to tolerate more UV exposure without significantly increasing your risk of cancer. And by continuing to be exposed to high UV levels, your body will continue to produce melanin to keep you protected. It's a feedback loop.
If you're genetically predisposed to having pale skin, but then expose your skin to higher levels of UV than your low melanin levels can guard against, you will sustain significant sunburn, and if you do this repeatedly you'll significantly increase your risk of skin cancer. But if you gradually expose yourself to moderate levels of UV you can gradually increase your melanin levels more safely, but only as far as your genetics allow. (This is theoretical of course; we know very well that it's very hard for fair-skinned people to expose themselves to UV light from the sun or tanning beds without overdoing it, hence the widespread occurance of skin cancer.)
My educated guess about the notion that dark skinned people are experiencing higher levels of cancer would be that if a dark-skinned person keeps avoiding UV for long enough, their melanin levels start to decline (due to it not being an optimal use of resources), but then if/when sun exposure happens, the protection isn't as strong and the risk of cancer is higher.
I'm curious as to whether your educated guess derives from a clinical background, or reddit?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2671032/
http://www.skincancer.org/prevention/skin-cancer-and-skin-of...
https://theconversation.com/amp/sun-damage-and-cancer-how-uv...
I know, I acknowledged that in my comment.
My main point was only about the extent to which people with genetically high melanin levels are at much lower risk of cancer (which your first link confirms), but how their risk might increase if their melanin levels drop.
I don't dispute that it's a complex and dangerous topic. And as someone with genetically very pale skin, I most certainly steer well clear of direct sunlight and make no efforts to develop a tan.
I'm curious as to whether your educated guess derives from a clinical background, or reddit?
That's a low blow :)
I rarely go anywhere near Reddit, certainly not for anything to do with health. I have spent 10+ years researching health topics for reasons to with serious, chronic, illnesses I've endured, and have now largely overcome thanks to what I've learned.
And even last year I heard girls talk about building up a 'base tan' before summer. Roasting like rotisserie chickens under the solarium lamps.
If they did, we would know, because workers compensation would be paying for it.
Yes, they do.
> If they did, we would know, because workers compensation would be paying for it.
While state workers comp laws vary in ways which make this different from state to state, workers comp is paying for it for some subset of people who work outside.
http://blogs.findlaw.com/injured/2015/06/can-i-get-workers-c...
"However, compared with the general population, the rates for certain diseases, including some types of cancer, appear to be higher among agricultural workers, which may be related to exposures that are common in their work environments. For example, farming communities have higher rates of leukemia, non-Hodgkin lymphoma, multiple myeloma, and soft tissue sarcoma, as well as cancers of the skin, lip, stomach, brain, and prostate."
https://www.cancer.gov/about-cancer/causes-prevention/risk/a...
My father, who worked outdoors most of his life, always wore long pants and long sleeves even on the hottest summer days. I did not understand why when I was younger. I now get it.
Science is trying to work this out, it is complex. We know that sun exposure both protects from and causes skin cancer depending on the study. This is a complex subject, the only thing I think I can safely say is don't get a sunburn.
https://wiki.cancer.org.au/skincancerstats/Settings:_Workpla...
It is estimated that around 200 melanomas and 34,000 non-melanoma skin cancers per year are caused by occupational exposures in Australia.[1]
http://www.cancer.org.au/content/pdf/PreventingCancer/BeSuns...
The 2006 Report on indicators for occupational disease highlights there was an increase in skin cancer claims per million employees/persons over a six-year period to 2004. The report says that given the long latency period associated with exposure and the onset of skin cancer, it is also likely that compensation claims greatly understate the real incidence of occupational skin cancer6 .
This is believed to be due to sun exposure of the left side while driving.
That's a bit of a blasé thing to say... I have lost direct family members through melanoma due to their work requiring them to be in the sun all day, and clearly many other people here have too. I can't fathom how you would form such an opinion.
My dad died of malignant melanoma. He wore sun screen all the time. He didn't swim. He would wear sun hats. He was paranoid, and likely had premonition of it. Unfortunately, his prevention methods might have actually exacerbated his odds even further because he was depriving his skin of one of its few natural healing modalities.
Talk to some people in the southern hemisphere (australia and nz). There is a LOT of awareness of sun damage in these countries.
It's a complex, dynamical issue and there is conflicting evidence about the effectiveness of sunscreen to just blanket reduce melanoma: https://www.ncbi.nlm.nih.gov/pubmed/22994908
Not only that, there have been some controversies about sunscreens themselves containing questionable ingredients, some of which might actually be carcinogenic. If you're going to market your product as cancer preventative, but go and put carcinogens into that very same product, my trust level in your industry has been reduced by somewhere in the range of 25%-75%.
Somehow, in all this, there are people who think any raw sun exposure is going to cause cancer. That's actually misinformation. Melanin is known to be a protective. How can one go about increasing melanin? By tanning in moderation, letting your skin adapt to the sun. Of course there are people who simply don't tan easily, and yes, they should be cautious. But I'm fortunate to have skin that tans, and I'm going to let it do that!
Check out JoeAltmaier's comment.
If you spend some time in the sun without getting a tan, it's still good for you even if you don't tan, as long as you're not burning.
do some product research and pick a reputable brand. but don't try to scare people off sunscreen by implying that it causes cancer!
If you have concerns about the chemical sunscreens, please use zinc oxide. It is totally non reactive.
Sun damage is cumulative, a tan is a reaction to damage. People with a tan have sun damaged skin.
Naturally very dark skinned people are different, and also have enhanced mechanisms to allow damaged cells to self-euthanize.
Ah! Research, gotta love it. UVA darkens directly as a result of action on the melanin. UVB damages DNA resulting in long-lasting production of more melanin.
Here's another study arguing that sunscreen might inhibit the inflammatory response without actually reducing the burn. Their abstract concludes "As such, sunscreens might promote instead of protect against melanoma." : http://journals.lww.com/melanomaresearch/Abstract/2005/02000...
SPF is actually measured by reduction of redness. That study points out that reduction of redness doesn't necessarily come with a reduction of damage!
If people are preventing their body from expressing its natural sun defenses and going out and overexposing themselves to the sun, believing themselves to protected... If that protection is illusory, that's kind of a recipe for disaster. People could be getting burned and not even know it... They won't even know to put aloe on.
Take that one with this one, which postulates that sun exposure isn't what causes malignant melanoma, sunburns are:
> Although there is convincing evidence that nonmelanoma skin cancer is related to cumulative sun exposure, there is less evidence of that association with CMM. If CMM were related to cumulative sun exposure, one would expect that outdoor workers would have a greater incidence of CMM than indoor workers. However, that is not the case. The incidence of CMM is actually increasing among indoor workers who receive three to nine times less solar UV radiation than outdoor workers. Furthermore, there is a higher incidence of CMM among whites living in northern states such Delaware, Vermont, and New Hampshire (>30 per 100,000), which enjoy less year-round sunlight and UV radiation than southern states such as Texas, Florida, Arizona, and New Mexico (<25 per 100,000). In California, whites living in San Francisco had a CMM incidence of 30.5 per 100,000, whereas those living in Los Angeles had an incidence of 24.9 per 100,000. There are a few studies that suggest that chronic, low-grade exposure to sunlight may be protective against CMM. In one Austrian study, those with chronic sun exposure without sunburn had a reduced incidence of CMM compared with those with recreational sun exposure. In Germany, outdoor activities during childhood, in the absence of sunburn, were associated with a lower risk of melanoma. Chronic, repeated sun exposure may allow the skin to accommodate to UV radiation by increasing melanin production, thereby reducing the risk of sunburn. An English study published in 2011 showed that regular weekend sun exposure had a protective effect against CMM, and the researchers postulated that this may be mediated by photo-adaptation or higher vitamin D levels.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3409870/
Anyway, please wear shades and a hat.
My point is that moderate sun exposure is healthy and good melanoma prevention. From what I've seen, there is quite a bit of research to back this up.
I think that better education about this would encourage people to develop healthy relationships with the sun at a young age. Right now the conventional wisdom seems to be "just throw sunscreen at it" / "stay out of the sun unless you are wearing sunscreen" and I think this totally misses the point.
My caution is that it's unwise to tell people to avoid sun exposure in total. While sunscreen does seem to be helpful in slowing sun damage, it'd also be unwise to suggest that sunscreen will protect people from overexposure, there isn't really evidence for that. There is a whole body of research. Take a look at some of the studies cited in this article http://m.jabfm.org/content/24/6/735.full
It's like avoiding eating food altogether because you might became obese, or worse (given the odds) choke on it.
Sun lotion can only prolong your safe time, but 0 times whatever is still zero, as in her case. So there is a difference.
On good old Earth, one can sit in the sun for hours on end without a burn. In fact people frequently do, like all the time.
https://www.livescience.com/46701-andes-highest-uv-index-mea...
More exposure to UV (eg sun exposure) leads to a greater chance of developing skin cancer.
Which is good because if I remember correctly the human skin has quit a bit natural sun protection, but is only fully developed in the twenties.
If I got that mixed up with something else please correct me if I'm wrong.