塑料的危害

Plastic is everywhere: water bottles, dental sealant, the odd floating trash island. Over the years, researchers have raised the alarm about how chemicals from plastics might affect human health, often focusing on one chemical in particular: bisphenol A (BPA).

塑料無處不在：水瓶、牙科密封劑、怪異的浮動垃圾島。多年以來，研究員就塑料中的化學物質或影響人類健康提出了警告，尤爲關注雙酚A（BPA）這一化學物質。

BPA is used to make a hard, clear type of plastic called polycarbonate. It's so ubiquitous that a 2009 study conducted by the Centers for Disease Control found that of the 2,517 people they tested, nearly all of them had detectable levels of BPA in their urine. New research hints that BPA-free plastic alternatives may not actually be any safer.

BPA被用來製作硬質透明型塑料，這種塑料被稱爲聚碳酸酯。BPA遍地都是，2009年疾病預防控制中心開展的一項研究發現：在2517位受試者中，幾乎所有人的尿液都可檢測到BPA。新研究表明不含BPA的塑料替代品可能也並不安全。

It all started 20 years ago, when researchers in the lab of geneticist Patricia Hunt realized that something was very wrong with their mice.

這一切始於20年前，當時遺傳學家帕特里夏·亨特（Patricia Hunt）實驗室的研究員意識到：他們的小鼠有問題。

The process of making a healthy egg cell involves a series of cell divisions, during which chromosomes (the long strands of DNA that make up an organism's genome) are divided up into the newly-formed cells. If something goes wrong and the cells end up with an abnormal number of chromosomes, that's usually a very serious problem.

製造健康卵細胞的過程包括一系列的細胞分裂，在此過程中，染色體（構成生物體基因組的長鏈DNA）會被分開形成新的細胞。如果出現問題，細胞的最終染色體數量便會異常，通常是一個非常嚴重的問題。

The researchers in Hunt's lab were studying this process when suddenly the egg cells of their mice--including the ones that were supposed to be normal--started showing major genetic abnormalities. Something in the environment of these mice was causing their egg cells to have problems dividing. It turned out that the problem was the plastic cages.

當時，亨特實驗室的研究員正在研究該過程，突然間，小鼠的卵細胞--包括本該正常的小鼠--開始顯現主要的遺傳異常。這些小鼠所處環境的某些因素導致了它們的卵細胞分裂有問題。結果發現：這一因素是塑料籠。

The mice were living in cages made of polycarbonate. A worker had accidentally used a harsh detergent to clean them, which caused them to release BPA. When the researchers replaced the cages, the egg cells went back to normal, and when they tried giving the mice BPA on purpose, the egg cells had the same problems as before. The researchers concluded that BPA is capable of causing genetic abnormalities in mice.

這些小鼠被關在由聚碳酸酯製成的籠子裏。一位工作人員不小心使用了強效清潔劑清潔籠子，從而導致BPA的釋放。當研究員替換這些籠子後，小鼠的卵細胞重新迴歸正常。但當他們有目的地給這些小鼠釋放BPA時，它們的卵細胞又出現了與之前一模一樣的問題。研究員得出結論：BPA這一化學物質會導致小鼠遺傳異常。

So, does this mean we should all go home and throw out all our plasticware? Maybe, maybe not. Humans have different metabolisms than mice, so it's completely possible that consuming the same substance could have a different impact on us, or have no impact at all.

所以，這是否意味着我們應該趕緊回家，扔掉所有的塑料製品？也許是，也許不是。人類的新陳代謝與小鼠不同，所以攝入同樣的物質可能會對我們產生完全不同的影響，甚至一點兒影響都沒有。