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I sunburn super easily.
我超容易曬傷的。
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It just takes a few minutes sitting in my garden or on a beach, and then a couple days later my skin starts peeling off.
只要在我家庭院或海灘坐上幾分鐘,幾天後,我就會開始脫皮。
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It’s seriously pretty gross—not exactly the effect most people go for when they sunbathe.
真的超噁心 — 這絕對不是普羅大眾做日光浴所追求的效果。
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But, what really happens when you get a sunburn?
但曬傷時,到底是發生什麼事啊?
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I’m Anna Rothschild, and this is Gross Science.
我是 Anna Rothschild,這裡是《噁心科學》頻道。
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Most burns occur if you come in contact with something hot, like when you scald the roof of your mouth on a slice of pizza.
大部分的燒傷在你碰觸到燙的東西時才會產生,比如說,吃比薩的時後燙到上顎。
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But sunburns are actually not caused by heat.
但曬傷其實不是因為高溫而造成。
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Sunlight is made up of a bunch of different types of radiation.
陽光是由一連串不同種類的光所組成。
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One of them is infrared radiation, which is primarily what makes sunlight feel hot.
其中一種為紅外光,它就是讓陽光產生熱的原因。
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But there’s also visible light, which allows us to see sunlight, and then there’s ultraviolet radiation.
還有可見光,它讓我們能看見陽光,另外還有紫外光。
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Ultraviolet, or UV, radiation is what causes a sunburn.
紫外線,或稱 UV 光,才是造成曬傷的元兇。
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It can wreak havoc on skin cells by disrupting important molecules, like DNA.
紫外線能藉由干擾皮膚細胞裡重要的分子,如 DNA,大肆破壞細胞。
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So, your body does its best to protect you from it.
所以身體會盡全力保護自己。
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When UV radiation hits your skin, pigments called melanin absorb it, and shield your DNA from harm.
當 UV 光照到肌膚時,黑色素會將其吸收,保護 DNA 不受其害。
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Now, melanin is present in our skin cells all the time—it’s what gives your skin its particular color.
黑色素一直都存在於皮膚細胞中 — 它就是讓我們有特定膚色的原因。
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It’s created by special cells called melanocytes, which then distribute the melanin to other cells called keratinocytes.
黑色素是由稱為黑色素細胞的特殊細胞製造,然後再被分配至角化細胞。
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Those are the most common cells in your outermost layer of skin.
角化細胞是外層皮膚最常見的細胞。
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When your skin is exposed to UV, the melanocytes ramp up their melanin production, and also transfer more melanin to the keratinocytes.
當肌膚照射到 UV,黑色素細胞就會提高黑色素的產量,並且運送更多黑色素至角化細胞。
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This happens to varying degrees based on your genetic makeup, but that’s why your skin might turn darker, or tan, if you’re out in the sun for a while.
反應程度取決於你的基因組成,這就是為什麼你在太陽底下晃一會兒,皮膚就會變黑、變深。
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But, the melanin defense is far from foolproof—regardless of how dark your skin is, or how much you tan, some UV rays can sneak past.
但黑色素的防禦是絕對不夠靠譜的 — 不管你本來膚色多黑、或把自己曬得多黑,有些 UV 光就是能避開這層防禦。
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And when they do, they can damage your DNA.
一旦通過防護,它們就會傷害你的 DNA。
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This can actually happen in a few different ways.
它傷害 DNA 的方式其實有好多種。
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Sometimes the radiation will directly zap your DNA, damaging it in just a trillionth of a second.
有時紫外線會直搗 DNA ,只需要不到兆分之一秒就能造成損傷。
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Alternatively, UV rays can do something more sinister—they can actually turn your melanin against you.
或者,UV 可以更邪惡一點——讓你的黑色素造反。
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The radiation can make your cells produce these harmful molecules called free radicals.
紫外線可以讓細胞產生稱為自由基的有害物質。
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Now, this is a little bit complicated, but essentially the free radicals excite an electron in your melanin. I'm excited!
事情有點複雜,但基本上,自由基會激發黑色素的一顆電子。我被激發了!
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The melanin then bumps into your DNA and excites an electron there. I'm excited too!
被激發的黑色素碰到 DNA ,進而激發 DNA 的一顆電子。我也是!
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—which can cause the DNA to kink.
——那會讓你的 DNA 變得病懨懨。
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Regardless of how it happens, once your cells are damaged they start producing warning molecules, signalling that something bad is going on.
無論是怎麼發生的,一旦細胞受損,它們就會開始製造警示物質,藉此來傳送噩耗。
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If enough cells produce the signal, your body will mount an inflammatory response, sending lots of different types of blood cells to the area to stop and repair the damage.
如果產生這種訊息的細胞夠多,身體就會啟動發炎反應,派出各種血球細胞到曬傷的地方,來制止並修復傷害。
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And it’s this influx of blood that causes the redness you typically see with a sunburn, depending on how light your skin is.
也就是因為血液匯集,才會形成典型曬傷的發紅症狀,發紅的情況要看你的膚色有多白。
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So, what about the peeling?
那麼,脫皮又是怎麼回事呢?
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Well, your skin cells are shedding all the time without you noticing it.
皮膚細胞其實一直在脫落,只是你沒注意到。
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You actually have stem cells in your skin that live for decades.
其實皮膚裡有幹細胞,它可以存活數十年。
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The stem cells produce layers of keratinocytes, which fall off and are replaced over time.
幹細胞製造層層的角化細胞,它會隨著時間脫落及更新。
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But those keratinocytes don’t mature properly when they’re damaged by UV.
但被 UV 損傷的角化細胞,它們不會正常地長大成熟。
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So instead of flaking off inconspicuously, they all clump up and peel off together.
它們不會小片小片、默默地剝落;而是成群結隊,一起脫皮離開。
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Now, your body actually has enzymes that repair a lot of the DNA damage caused by UV rays.
其實身體裡有些酵素,它們能修復很多 UV 光所帶來的 DNA 傷害。
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But, it can’t always repair all of it.
但它不是每次都能修復所有的傷害。
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And if the damage isn’t fixed in one of your stem cells, you might have a real problem.
如果其中一個幹細胞裡的傷害沒被修復,事情就大條了!
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When those cells replicate, they might create a mutation at the site of the damage.
當幹細胞複製時,受傷的地方可能會發生突變。
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And depending on where the mutation occurs, this could lead the cell to become cancerous sometime down the road.
根據發生突變的不同位置,之後很可能會讓細胞轉變成癌細胞。
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Remember, even if you don’t tend to burn, UV radiation can damage your DNA.
記住,就算你不容易曬傷,UV 光還是會傷害你的 DNA。
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So if you know you’re going to be out in the sun for a while, make sure you’re covered up or wearing sunscreen.
所以如果知道自己等等要頂著太陽外出一下,請確保把自己遮好或是擦上防曬。
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For me, being outside and exploring the world is super important for my happiness, and excites my curiosity.
對我來說,在外探索世界是件超重要的樂事,它能激起我的好奇心。
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But it’s way more fun to go on an outdoor adventure without coming home to disgusting peeling skin.
但如果可以出外大肆探險、回家時又不會有噁心的脫皮的話,就太完美了。
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Got a question about sunburns? Let me know in the comments.
還對曬傷有問題嗎?留言讓我知道吧!
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And for more gross science, hit subscribe.
按下訂閱以了解更多《噁心科學》。