too—being swept up to great heights, traveling  with the wind, and raining back down on Earth. 

也是如此--被捲到很高的地方，隨風而行，然後雨點般落在地球上。

And now an international team  of scientists have figured out  

而現在，一個國際科學家團隊已經找出了

where they're coming from—and the places are  probably not what you'd expect. But how does  

他們來自哪裡--這些地方可能不是你所期望的。但如何

all this plastic in the air affect our health?

空氣中的所有這些塑膠影響我們的健康？

Let's start with the basics. Microplastics  

讓我們從基本知識開始。微塑膠

are tiny specks of plastic less than 5  millimeters long—think anything shorter than the  

是不到5毫米長的微小塑膠斑點--認為任何短於5毫米的東西都是不可能的。

width of a pencil eraser. They come in two main  categories. The first type is known as primary,  

鉛筆橡皮的寬度。它們主要有兩大類。第一類被稱為初級。

which are already small plastics, like glitter,  and are directly released into the environment.  

其中已經是小的塑膠，像閃閃發光，並直接釋放到環境中。

The other type is secondary microplastics,  which form when larger plastics degrade. 

另一種類型是次級微塑膠，在較大的塑膠降解時形成。

Most plastics are broken down through  weathering, like when they're exposed to waves,  

大多數塑膠通過風化作用被分解，比如當它們暴露在海浪中時。

wind abrasion, and UV radiation. And depending on  the type of plastic, it can take up to hundreds  

風的磨損，和紫外線輻射。而且，根據塑膠的類型，它可能需要多達數百個

of years to break down, if at all. And because  microplastics are so tiny and lightweight, they  

如果有的話，也需要幾年的時間來分解。而且，由於微塑膠是如此之小和輕，它們

can be transported over long distances globally.

可以在全球範圍內進行長距離的運輸。

-We were really interested  

-我們真的很感興趣

in first understanding how much plastic is  being deposited. But then we wanted to ask,  

在首先了解有多少塑膠正在被沉積。但後來我們想問。

Where is it coming from? How long can  it stay in the atmosphere? And how is  

它是從哪裡來的？它能在大氣中停留多長時間？以及如何

it getting into the atmosphere to begin with?

它開始進入大氣層？

So, Dr. Brahney and her colleagues tackled  

是以，Brahney博士和她的同事們解決了

those questions using atmospheric  transport modeling and data from  

使用大氣傳輸模型和數據對這些問題進行研究。

sampling sites in the western United States.

在美國西部的採樣點。

-We estimated that somewhere between 1000 and  

-我們估計，大約有1000至

4000 tons of microplastics are being  deposited into Western protected areas. 

4000噸的微塑膠正在沉積到西部保護區。

And this is the equivalent to about 100 million  to 400 million plastic bottles every single year. 

而這相當於每年約1億至4億個塑料瓶。

The team found that 84 percent of those  microplastics likely originated from roads. With  

研究小組發現，這些微塑膠中有84%可能來自於道路。隨著

the rest coming from oceans and agricultural dust.

其餘的來自海洋和農業灰塵。

So, why are we seeing so much microplastic  

那麼，為什麼我們會看到這麼多的微塑膠？

coming from roads? Well, roads and  the cars that drive on them provide  

來自道路？嗯，道路和在其上行駛的汽車提供了

the mechanical energy needed to make plastic  airborne. As you're racing down the highway,  

使塑膠升空所需的機械能。當你在高速公路上飛馳時。

tiny bits of tire and other microplastics  stuck to your tire fling off and fly away. 

粘在你的輪胎上的微小的輪胎碎片和其他微塑膠會被甩掉並飛走。

-I think of it much like the way  people move sand away from a beach,  

-我認為這很像人們從海灘上移走沙子的方式。

cars can move plastic away  from cities, and then also  

汽車可以把塑膠搬離城市，然後還可以

move those plastics high into the atmosphere.

將這些塑膠轉移到高空。

-We're already seeing the negative effects  

-我們已經看到了負面的影響

of microplastic pollution. Limited research  has also revealed that microplastics affect the  

的微塑膠汙染。有限的研究還顯示，微塑膠影響了

health of plants and animals, which has impacts  on the entire food chain. And as microplastics  

植物和動物的健康，這對整個食物鏈都有影響。而由於微塑膠

clutter our land, waterways, and atmosphere in  higher concentrations, we'll have to monitor  

在我們的土地、水道和大氣中的濃度更高，我們將不得不監測

if and how they might change atmospheric  processes too. There's also the unsettling  

如果它們也可能改變大氣過程，以及如何改變。還有一個令人不安的問題

potential of how they could be affecting us.  Some of these microplastics are small enough  

它們如何影響我們的潛力。 這些微塑膠中有些小到足以

to be inhaled into the human pulmonary system.

被吸入人的肺部系統。

Once these tiny plastics get into the body,  

一旦這些微小的塑膠進入體內。

they can have quite a big number of effects.  Some larger microplastics can be filtered out of  

它們可以產生相當多的影響。 一些較大的微塑膠可以被過濾掉。

our respiratory system when we cough, sneeze, or  blow our nose. But limited research suggests that  

當我們咳嗽、打噴嚏或擤鼻涕時，我們的呼吸系統就會出現問題。但有限的研究表明

smaller microplastics can reach and remain  in the respiratory system, and continued  

較小的微塑膠可以到達並留在呼吸系統中，而持續的

exposure to plastic, like when you're working in a  synthetic fiber factory, can lead to inflammation,  

接觸塑膠，如在合成纖維工廠工作時，會導致發炎的發生。

lesions, and respiratory conditions.  

病變和呼吸系統疾病。

Unfortunately though, we don't have 

但不幸的是，我們沒有

enough info on how everyday exposure to plastics  affects us. I.E. not in a plastic factory. So,  

足夠的資訊表明每天接觸塑膠對我們有什麼影響。即不是在塑膠工廠。所以。

some scientists are trying to find out more.

一些科學家正試圖找出更多的線索。

In 2019, an international team of  

在2019年，一個國際團隊的

scientists used dummies to mimic the  inhalation of microplastics indoors.  

科學家們用假人來模擬在室內吸入微塑膠的情況。

The study found microplastics in every sample  of air. A more recently published study from  

該研究在每個空氣樣本中都發現了微塑膠。最近發表的一項研究來自

Florida State University focused on the impacts  of microplastic exposure on the cellular level.  

佛羅里達州立大學重點研究了微塑膠暴露在細胞水準上的影響。

After exposing human lung cells to  polystyrene microplastic spheres,  

將人類肺部細胞暴露於聚苯乙烯微塑膠球后。

the team saw their metabolic processes slow down  and rings of microplastics form around the nuclei. 

研究小組看到它們的新陳代謝過程放緩，核周圍形成了微塑膠環。

But none of the cells died. These studies are still  

但沒有一個細胞死亡。這些研究仍然是

very limited, but they are getting us closer  to understanding how the accumulation of  

非常有限，但它們讓我們更接近於瞭解

plastic in our environment, particularly  our atmosphere, is affecting human health. 

我們環境中的塑膠，特別是我們的大氣，正在影響人類健康。

What we know for sure is that if our plastic  production and consumption continues to grow in  

我們可以肯定的是，如果我們的塑膠生產和消費繼續增長，在

the coming decades as expected, plastic pollution  will increase too. And we're just starting  

在未來的幾十年裡，正如預期的那樣，塑膠汙染也將增加。而我們才剛剛開始

to understand what those impacts will be. -Well, I think we can't ever begin to start  

以瞭解這些影響將是什麼。-嗯，我認為我們永遠不能開始

mitigating an issue until we really understand it.  So understanding not only how plastics are  

在我們真正瞭解一個問題之前，要減輕它的影響。 是以，不僅要了解塑膠是如何

being deposited and moving through the atmosphere,  but how they're getting into the atmosphere is, is  

沉積並通過大氣層移動，但它們是如何進入大氣層的，是

really critical for us mitigating the  amount of plastics that are emitted. 

這對我們減少塑膠的排放量真的很關鍵。

-If you want to learn more about the creative ways  scientists are combating COVID's plastic problem,  

-如果你想了解更多關於科學家們對抗COVID塑膠問題的創造性方法。

check out that video here. Let us know in  the comments what else you want to know  

在這裡查看該視頻。請在評論中告訴我們你還想知道什麼

about microplastics. Make sure to subscribe to  Seeker for more groundbreaking science news.  

關於微塑膠。請務必訂閱Seeker，瞭解更多突破性的科學新聞。

Thanks so much for watching and  I'll see you next time on Seeker.

非常感謝你的觀看，我們下次在Seeker上見。