快捷搜索: 紐約時報  誠信  教育  經濟學人  中國  香港 

夏日護膚:防曬霜的紫外線過濾劑是否安全

Sunscreen: What science says about ingredient safety
夏日護膚:防曬霜的紫外線過濾劑是否安全

Melanoma is one of the deadliest cancers. It’s also one that – while still the least common form of skin cancer – is rising in prevalence around the world. Since the early 1990s, rates of melanoma in the UK have increased among every age group. Rates of non-melanoma have increased too. In the US alone, cases of non-melanoma skin cancers have grown by around 77% over the past two decades.

黑色素瘤是致死率最高的癌癥之一。盡管這種皮膚癌并不常見,但其患病率在全世界正在上升。自20世紀90年代早期以來,英國各年齡層的黑色素瘤患病率均有所增長。非黑色素瘤皮膚癌也在上升。僅在美國,過去20年間非黑色素瘤皮膚癌病例就增長了77%左右。

Exposure to UV radiation is the main cause of the most common forms of skin cancer. And one of the most effective ways to avoid it, of course, is sunscreen.

皮膚過量暴露在紫外線中是引發皮膚癌的最主要因素。顯而易見,最有效的預防方式就是使用防曬霜。

“Any conversation on sunscreen must start with acknowledging that there is robust evidence that it prevents skin cancer,” says Richard Weller, honorary consultant dermatologist at the University of Edinburgh.

英國愛丁堡大學名譽顧問皮膚科醫師維勒(Richard Weller)表示,“任何關于防曬霜的討論,前提都必須是承認有足夠的證據證明防曬霜可以預防皮膚癌。”

This is why, although skin cancer is rising in some countries, it’s decreasing in others – particularly those that have raised the most awareness around the importance of using sunscreen. “Skin cancer rates are increasing among older generations – they’re carrying damage from decades earlier in their lives, because things have changed now,” says Adele Green, senior scientist of the cancer and population studies group at QIMR Berghofer Medical Research Institute in Australia. “Countries where rates are falling have had the biggest investments in communicating awareness, such as New Zealand, Denmark, the US and Australia.”

這就是為什么某些國家的皮膚癌患病率在上升的同時,其他國家,尤其是那些人們意識到使用防曬霜重要性的國家,皮膚癌患病率卻在下降。澳大利亞昆士蘭QIMR伯格霍夫醫學研究所(QIMR Berghofer Medical Research Institute)癌癥及人口研究資深科學家格林(Adele Green)表示,“皮膚癌在老年人群中發病率上升,因為他們皮膚在人生前幾十年已開始曬傷,進入晚年后,曬傷的皮膚發生了癌變。在宣傳皮膚癌防范意識投入最多的國家,皮膚癌發病率正在下降,其中包括新西蘭、丹麥、美國和澳大利亞。”

But some researchers have raised concerns that, despite being an undeniably important tool in our fight against skin cancer, the formulation of sunscreen may need to be improved to contain safer ingredients – and, at worst, some sunscreens could be damaging our health.

但一些研究人員擔心,雖然毫無疑問,防曬霜是預防皮膚癌的重要工具,但其配方可能需要進一步改善、使用更安全的成分,而且最壞的情況是,有些防曬霜可能危害健康。

Earlier this year the US Food and Drug Administration (FDA) – one of the two main global regulators of sunscreen ingredients around the world alongside the European Commission – removed 14 of the 16 chemicals found in sunscreens from its GRASE (generally accepted as safe and effective) category.

今年年初,歐盟以外的全球最大防曬霜成分監管機構美國食品藥物管理局(FDA)將防曬霜里常見的16種化學物質中的14種從“公認安全有效(GRASE)”類別中移除。

So what is the reality?

那么,事實究竟如何呢?

Double filter

兩種過濾紫外線的防曬劑

Two types of UV filters can be used for sunscreen. The most commonly used are known as organic filters, which absorb UV radiation and convert it into safer radiation. Inorganic UV filters like titanium dioxide and zinc oxide – which are broadly considered safe – reflect and scatter UV radiation away from the skin.

有兩類紫外線過濾物質可用于防曬霜。最常用的一種被稱為有機過濾防曬劑,能吸收紫外線,然后將其轉化為對人體皮膚較安全的輻射。另一種是氧化鈦和氧化鋅等無機紫外線過濾物質,能夠反射、散射紫外線,使其無法傷害皮膚,廣泛認為很安全。

It’s long been established that some organic filters are absorbed through the skin and into the bloodstream. This alone doesn’t mean sunscreen is unsafe, but there is growing focus on the potential adverse effects of the most common UV filter worldwide: oxybenzone.

長期以來,人們一直認為某些有機過濾防曬劑會被皮膚吸收,然后進入血液。僅這一點并不意味著防曬霜不安全,但人們越來越關注全球最常見的紫外線過濾劑羥苯甲酮潛在的不利副作用。

“Little is known about systemic exposure for most active ingredients” in sunscreens, the FDA stated in its report, referring to the effects of large volumes of sunscreen absorbed through the skin and into the body.

美國食品藥物管理局的報告提到經皮膚大量吸收進體內的防曬劑之作用時稱,有關防曬液“中最活躍物質如何系統性起作用的真相,我們所知少之甚少”。

FDA scientists authored a paper focusing on four ingredients found in sunscreen into the skin, including oxybenzone, and concluded that absorption of sunscreen into the body may be more than a theoretical concern. However, the trial was very small – involving only 24 people.

美國食品藥物管理局的科學家們撰寫了一篇論文,對4種防曬霜中進入皮膚的化學成分進行研究,其中包括羥苯甲酮等,得出這樣的結論:被人體吸收的防曬劑確實可能影響健康。但是,實驗規模非常小,僅有24人參與。

Some lab and mice studies have found that some organic UV filters, including oxybenzone, as well as ingredients including parabens and phthalates, which can be found even in sunscreens that use inorganic UV filters, are suspected endocrine disrupters: chemicals that interfere with our hormones. But no research on humans has backed this up.

一些實驗室對老鼠的研究發現,包括羥苯甲酮在內的某些有機紫外線過濾劑、以及用于無機紫外線過濾防曬霜中的對羥基苯甲酸酯和鄰苯二甲酸鹽等成分,都可能是內分泌干擾物,即會干擾動物激素的化學物質。但是目前沒有針對人體的此類研究可以證明這一結論。

Laura Vandenberg, associate professor at the University of Massachusetts Amherst's School of Public Health and Health Sciences, says most endocrine disrupters affect male foetuses and embryos.

美國馬塞諸塞州立大學阿默斯特公共衛生與健康科學學院(Amherst's School of Public Health and Health Science)副教授范德堡(Laura Vandenberg)表示,大多數內分泌干擾物會影響男性胎兒和胚胎。

High-level exposure to phthalates, in particular, has been found to disrupt development of male genitals. This could lead to problems later in life, such as reduced sperm count or increased risk of testicular cancer. However, this effect has only been found in very high doses.

接觸高劑量的鄰苯二甲酸鹽,尤其會干擾男性生殖器官的發育。這可能導致以后人生的許多問題,例如精子數量下降或睪丸癌風險上升。但這一影響僅在劑量極高時發生。

These compounds aren’t just in sunscreens, either. Phthalates also can be found in various other cosmetics, including some soaps, shampoos, nail polishes and hair sprays, and parabens are in many hair care and make-up products.

這些化合物也不只是存在于防曬霜中。某些香皂、洗發水、指甲油、頭發噴霧等其他美容產品也含有鄰苯二甲酸鹽,而許多護發和美妝產品中則含有對羥基苯甲酸酯。 紐約時報中英文網 http://www.uydujn.live

Meanwhile, Vandenberg has found through her research that oxybenzone can affect the size of mice’s mammary glands. Oxybenzone also has been detected in breast milk. That means it could also be in the breast tissue, Vandenberg says, which could affect its development, function and health.

與此同時,范德堡還通過研究發現,羥苯甲酮可以影響老鼠的乳腺大小,而且在老鼠母乳中也檢查到有這種化學物。范德堡表示,這意味著乳房組織內可能也含有羥苯甲酮,這會影響乳房的發育、功能和健康。

However, we should always be cautious when applying the findings of mice studies to humans, says David Leffell, professor of dermatology and surgery at Yale School of Medicine, who was not involved in the research.

但是,沒有參與研究的耶魯大學醫學院皮膚科及外科教授勒費爾(David Leffell)表示,我們不應輕易地將老鼠實驗的研究結果推定到人體上。

Critics also say research showing adverse effects of UV filters on rodents typically involved much higher levels of UV filters than human use.

批評者也表示,在老鼠身上做的實驗顯示,在這些嚙齒類動物身上使用紫外線過濾物產生不利作用,其劑量遠遠高于人類日常的使用量。

For example, in 2011, a group of researchers writing in the journal Environmental Health Perspectives put into perspective the findings of one study from 2001. In that study, researchers observed that feeding oxybenzone to young rats caused their uteruses to grow by 23%.

例如,2011年一組研究人員在《環境健康視角》期刊中發表的文章就審視了2001年一項研究的觀點。在2001年的研究中,研究人員觀察到,給幼鼠喂食羥苯甲酮將導致其子宮增大23%。

The 2011 researchers calculated that to achieve the same cumulative amount of oxybenzone that was administered to the rats, the average US woman would have to apply sunscreen daily for anywhere from 34 to 277 years, depending on how many times they applied sunscreen per day.

2011年的研究人員經過計算,發現要達到與研究中老鼠同等的羥苯甲酮攝入量,美國女性平均需連續使用防曬霜34至277年,具體時長則取決于防曬霜的每天使用次數。

Even so, some research has found that organic UV filters may affect humans too. In one study from 2015, researchers studied 500 couples who were trying to conceive and found that male partners with higher concentrations of benzophenone-type UV filters had a 30% lower chance of conceiving each menstrual cycle.

即便如此,一些研究也發現,有機紫外線過濾劑可能對人類產生影響。在2015年的一項研究中,研究人員對500對正嘗試懷孕的夫婦展開研究發現,使用含較高濃度的二苯甲酮型紫外線過濾劑防曬霜的男性,其伴侶每月月經周期受孕幾率要低30%。

“The longer time to pregnancy may be influenced by subtle changes in semen quality,” says the study’s author Germaine Louis, professor of global and community health at George Mason University in Virginia, US.

美國弗吉尼亞喬治梅森大學(George Mason University)全球及社區健康教授、該研究的作者路易斯(Germaine Louis)說,“受孕所需時間較長可能受到精子質量的細微影響。”

While this is an important finding, the study does have limitations, Leffell notes, which Louis acknowledges in the paper. These limitations include reliance on only one urine measurement, and the possible variability of the concentration of UV filters measured, as their concentration lowers quickly when in the body.

勒費爾指出,雖然這是一項重要的發現,但該研究確實存在局限性。路易斯也在研究中承認了這一點。這些局限包括僅依賴一次尿液檢測,以及由于紫外線過濾劑在體內時濃度會快速降低,這可能導致所測量的成分濃度發生變化。

While it’s reasonable to be concerned about the clinical impact of certain benzophenones, regardless of their source, Leffell adds that the study doesn’t draw any definite conclusions.

勒費爾補充說,雖然無論二苯甲酮源自何處,擔心某些二苯甲酮的臨床影響是合理的,但這項研究并沒有得出任何確切的結論。

Vitamin D

維生素D

Aside from any one precise ingredient, there are concerns that sunscreen prevents the human body from making vitamin D, which we mostly get from Sun exposure. After all, vitamin D deficiency might be more prevalent than we think – could sunscreen use be to blame?

人們除了對防曬霜的某種確切成分表示擔憂之外,還擔心防曬霜會阻礙人體生成維生素D,因為這類維生素主要通過曬太陽獲得。畢竟,缺乏維生素D可能比我們所認知的要更為常見。那么,使用防曬霜是罪魁禍首嗎?

It shouldn’t be a major cause, says Rachel Neale, associate professor at QIMR Berghofer. “The mechanism of sunburn is different to vitamin D production, and there is a weight of evidence suggesting that applying sunscreen doesn’t seem to influence vitamin D levels much,” says Neale.

QIMR伯格霍夫醫學研究所助理教授尼爾(Rachel Neale)表示,這不應該是一個主要原因,“因為導致曬傷的機制和人體曬太陽產生維生素D的機制并不相同。有大量證據顯示,使用防曬霜似乎不大會影響維生素D的水平。”

“We’re very good at making vitamin D. And sunscreen isn’t like being inside a room – it screens the Sun out and still lets some through.”

尼爾說,“人體非常善于制造維生素D,而且使用防曬霜并不像是待在室內躲避陽光,只是擋住太陽,但還是會讓一些光線穿過。”

A panel of 13 leading experts from around the world met in 2018 to discuss the balance of vitamin D and Sun protection and concluded that sunscreens are unlikely to affect the vitamin D status of healthy adults.

來自世界各地的13位頂級專家組成的小組曾在2018年開會,討論維生素D和防曬霜之間的平衡,最終得出結論,防曬霜不太可能影響健康成年人的維生素D水平。 紐約時報中英文網 http://www.uydujn.live

For those concerned about getting enough vitamin D, Neale still advises wearing sunscreen every day for those living in places where there’s strong sunshine all year round, like Australia. But in places where the Sun isn’t so strong, like the UK, she says it’s easy to get vitamin D from Sun exposure because sunscreen usually is only needed when you’re outdoors for an extended period of time.

對于那些擔心維生素D攝入量是否充足的人,尼爾仍然建議,如果他們居住在澳大利亞等全年日照強烈的地區,還是需要每天使用防曬霜。但她表示,在日照不是那么強烈的地區,例如英國,人們可以很容易通過曬太陽獲得維生素D,防曬霜通常只需要長時間在戶外時才使用。

Concerns around sunscreen blocking vitamin D production also may be overstated because so few people use sunscreen correctly, according to Weller. It’s advised we apply two mg/cm2 to our skin, around six teaspoons, which is the amount used to determine a products’ Sun protection factor (SPF). Most people apply around a quarter of that, he says.

維勒表示,人們對防曬霜阻礙維生素D生成的擔憂也可能是過慮了,因為很少有人能夠正確地使用防曬霜。防曬霜的建議使用量是每平方厘米皮膚應為2毫克,約為6茶匙,這即是用來確認能起到防曬效果的標準劑量(SPF)。他說,大多數人大概只用了建議使用量的四分之一。

But could Sun exposure provide benefits other than vitamin D?

不過,除了幫助生產維生素D以外,曬太陽還有其他的益處嗎?

It’s important to note that any argument emphasising the Sun’s health benefits, rather than risks, remains a controversial theory – and it doesn’t negate the warning that exposure increases the risk of skin cancer however we’re exposed to it.

需要注意的是,任何強調太陽有益健康、卻不談論風險的理論至今都是爭議很大的理論,而且這種理論也不否認無論以何種方式暴露在太陽下,都會增加患皮膚癌的風險。

Still, one such benefit could be that UV radiation releases nitric oxide, a molecule produced in the body that dilates blood vessels and lowers blood pressure, which suggests that sunscreen may prevent these benefits, according to Weller.

維勒指出,即便如此,曬太陽其中一個益處就是吸收紫外線能幫助人體釋放一氧化氮。人體內的一氧化氮可以擴張血管、降低血壓,而使用防曬霜就可能形成阻礙。

“A growing body of evidence suggests [nitric oxide] is important for cardiovascular health and probably reduces cardiovascular disease, which is more important than preventing skin cancer,” he says.

“有越來越多的證據顯示,(一氧化氮)對心血管健康很重要,而且可能減少心血管疾病發病率。其重要性遠遠高于預防皮膚癌。”他說。

Weller argues reducing the risk of cardiovascular disease is more important than reducing rates of skin cancer because, while rates of both are rising globally, heart disease kills a much larger proportion of people. Cardiovascular disease is the number one cause of death globally – 17.9 million people died from the disease in 2016, while between two and three million non-melanoma skin cancers and 132,000 melanoma skin cancers are diagnosed each year. Melanoma, the more aggressive of the two, has an estimated average survival rate of around 92%, and experts say death from non-melanoma cancers is rare.

維勒認為,降低心血管疾病風險遠比降低皮膚癌風險重要,因為雖然兩者的患病率在全球范圍內均有增長,但心血管疾病的致死數量大得多。心血管疾病是全球排名第一的死亡原因,2016年就有1790萬人因此而死亡。相比之下,每年確診的非黑色素瘤皮膚癌和黑色素瘤皮膚癌的病例僅有200到300萬。據估計,即或較為危險的黑色素瘤皮膚癌,患者平均存活率也高達約92%,而且專家表示,非黑色素瘤皮膚癌導致的死亡則非常罕見。

However, Weller acknowledges that his argument is controversial, and that the strongest body of evidence we have clearly points to sunscreen being beneficial to our health.

然而,維勒也承認自己的觀點具有爭議性,大家手頭上最有力的證據也證明防曬霜對人們的健康有益。

Meanwhile, some argue that the confidence sunscreen gives us could be one reason why skin cancer rates are rising, particularly among older generations. Sunscreen emboldens us to spend longer in the Sun than we would otherwise, says Leffell.

與此同時,有的人認為,防曬霜給了人們信心,這可能是皮膚癌發病率上升的原因之一。這一點在老一輩人中尤甚。勒費爾說,防曬霜讓人勇于在太陽下待得更久。

“Talking to patients, it seems people tend to not reapply sunscreen regularly when outdoors, which we need to do. The chemicals act as a sink for UV energy, and they’re not inexhaustible,” he says.

他說:“我們在和病人的交談中發現,許多人在室外似乎不會定時補涂防曬霜,而這正是我們需要去做的。這些化學物質就好比紫外線能量儲存池,不是用之不竭,需要不斷補充。”

Animal planet

動物星球

It’s not just human health that scientists are investigating. Dozens of studies have demonstrated that UV filters pose a risk to marine life. Many of these chemicals can contaminate marine mammals, sea birds, fish and corals.

科學家們正在研究的并不僅限于人類健康。數十項研究表明,紫外線過濾劑對海洋生物造成了威脅。其中許多化學物質會污染海洋哺乳動物、海鳥、魚類和珊瑚。

And while even inorganic filters, like titanium dioxide, can have an effect, one of the most toxic culprits is oxybenzone – one reason why some destinations, like Mexico’s ecological park Xcaret and Xel-Ha, have enforced a policy whereby visitors must trade in their sunscreen for one which is more biodegradable.

即便是氧化鈦等無機過濾劑也可能產生影響,其中毒性最大的罪魁禍首之一就是羥苯甲酮,因此墨西哥生態公園Xcaret和Xel-Ha均制定了相關政策,要求游客必須將防曬霜更換成指定的可生物降解版本。

“Chemicals like oxybenzone can act as endocrine disruptors and cause sex change in fish, reduced growth or egg output,” says Cheryl Woodley, research scientist at the US National Oceanic and Atmospheric Administration.

美國國家海洋和大氣管理局研究員伍德麗(Cheryl Woodley)說,“羥苯甲酮等化學物質可以干擾內分泌,進而導致魚類性別發生改變,魚類增長量或產卵量將降低。”

“Pollution in the environment from chemical sunscreens can result in a reduced resilience to climate change events, and even contribute to reproductively impaired organisms, including  coral and fish, that can go locally extinct in a matter of generations by inducing sterility and reproductive failure.”

“防曬化學物質造成的環境污染會降低環境對氣候變化的抵御能力,甚至造成珊瑚、魚類等生物的生殖障礙,進而造成生物不育和繁殖失敗,最終導致當地生物將在幾代人的時間內滅絕。”

In one study looking at coral communities in Hong Kong waters, researchers found higher levels of sunscreen when there is increased human activity on the coast. Some coral samples contained levels high enough to cause deformities and death in immature corals.

研究人員在研究香港水域內的珊瑚群時發現,海邊人類活動增加時,珊瑚中防曬霜的含量就較高。部分珊瑚樣本含有的防曬濃度足以導致生物畸形和死亡。

So what should someone concerned about their health, or that of the seascape, do?

那么擔心珊瑚健康狀況或者相應海域景觀的人們應該做些什么呢?

Until there is definitive research on the potential effects of UV filters absorbed into our bodies, or alternatives that don’t contain ingredients associated with health risks, the consensus among experts is that we need to shield ourselves whenever we’re exposed to the Sun.

不過在有確切研究證明人體吸收的紫外線過濾劑可能有害于健康之前,或者我們可以找到不會有不潛在危險的替代品之前,專家們一致認為,只要我們暴露在太陽光下,就要做好防曬措施。

The healthiest way to do so – for both ourselves and for wildlife – is with clothing, finding shade and avoiding midday Sun. But for times that isn’t possible, we should both wear sunscreen and must apply it properly.

對我們和對野生動植物而言,最健康的方法就是使用衣物遮擋陽光、尋找蔭蔽、及避開正午的當頭日曬。但做不到這些的時候,我們就應該遵照正確的方法使用防曬霜。

For those concerned about potential effects of UV filters being absorbed into your skin or by wildlife, a sunscreen containing inorganic filters may be the better option.

對于那些擔心紫外線過濾劑被人體皮膚或動植物吸收、造成潛在危險的人,較好的選擇是使用含有無機過濾劑的防曬霜。

That may sound simple enough. But rising skin cancer rates suggest the message has been lost.

但聽起來簡單做起來難,皮膚癌發病率的上升意味著很多人只是聽聽而已,并沒有這么做。

網站部分信息來源于自互聯網和網友上傳,只為方便大家查詢瀏覽,請自行核對信息的真實情況,本站將不承擔任何責任!

您可以還會對下面的文章感興趣:

  • 36小時環游新加坡
  • 中國頒布新規,限制未成年人玩游戲
  • 辭掉工作、花了57天,他們找回了走失的狗
  • 改善健康也許很簡單:每天少吃300卡
  • 中國志愿者網絡“樹洞救援隊”用AI救援數百位自殺者
  • 最新評論

    留言與評論(共有 條評論)
       
    驗證碼:
    pk10九码滚雪球计划表