多久洗一次床单最合适？

We spend more than a third of our lives in bed - but that place can quickly blossom into a "botanical park" of bacteria and fungus , according to New York University microbiologist Philip Tierno.
我们有超过三分之一的时间都待在床上，但纽约大学的微生物学家菲利普·提艾诺表示，那里可能会迅速变成细菌和真菌的“植物园”。

If left for too long, the microscopic life within the wrinkles and folds of our bed sheets can even make us sick, Tierno said.
如果床单褶皱里的微生物停留的时间太长，它们甚至会使我们生病，提艾诺说道。

To stem the invisible tide, he said sheets should be washed once a week.
他表示，为了阻止这种暗藏的趋势，我们应该一周洗一次床单。

Humans produce roughly 26 gallons of sweat in bed every year. When it's hot and humid outside, this moisture becomes what scientists call an "ideal fungal culture medium."
人类每年在床上会流下大约26加仑的汗水。当外面又热又潮的时候，这些水分会变成科学家口中“理想的真菌培养基”

In a recent study that assessed the level of fungal contamination in bedding, researchers found that pillows between 1.5 and 20 years old can contain between four and 17 different species of fungus.
最近的一项研究检测了床上的真菌污染水平，研究人员发现，用了一年半的枕头里可能有四种不同的真菌，而用了二十年的枕头里可能有十七种不同的真菌。

And it's not just your own microbial life you're sleeping with. In addition to the fungi and bacteria that come from your sweat and skin cells, you also share your bed with foreign microbes.
你睡觉时藏在你周围的微生物不仅仅来自你自身。除了你的汗液和皮肤细胞带来的真菌和细菌，你的床上还有外来的微生物。

These include animal dander, pollen, soil, lint and dust mite, to name a few.
举几个例子来说，这包括动物毛屑、花粉、土壤、纤维屑以及尘螨带来的微生物。

Tierno says all that gunk becomes "significant" in as little as a week. And unclean bedding still exposes you to materials that can trigger the sniffing and sneezing, since the microbes are so close to your mouth and nose that you're almost forced to breathe them in.
提艾诺表示，所有的这些讨厌的微生物在一周的时间里就会变得“不可忽略”。因为这些微生物离你的鼻子和嘴那么近，而不洁净的床上用品使你接触到那些会让你抽鼻子和打喷嚏的物质，你几乎是被迫把那些微生物吸入了体内。

"Even if you don't have allergies per se, you can have an allergic response," Tierno said.
“即使你本身不过敏，你可能也会有过敏性反应，”提艾诺说道。

Another reason your sheets get dirty quickly has little to do with your behaviour or sweat patterns - the issue is simply gravity.
你的床单很快就变脏的另一个原因与你的行为或流汗关系不大，这只不过是引力的问题。

"Just like Rome overtime was buried with the debris that falls from gravity, gravity is what brings all that material into your mattress," Tierno said.
“就像重力会引起碎片的坠落，而超过一定时间，罗马就会埋葬在这些碎片中一样，重力也会把所有的那些物质带到你的床垫上，”提艾诺说道。

One to two weeks of this build-up is enough to leave anyone with a scratchy throat - especially those with significant allergies or asthma.(One in six Americans have allergies.)
这些物质积累一到两周就足以让任何人喉咙沙哑，特别是那些有严重过敏症或哮喘的人。（六分之一的美国人都有过敏症。）

"If you touched dog poo in the street, you'd want to wash your hands," said Tierno. "Consider that analogous to your bedding.”
“如果你在街上碰到了狗便便，你就会想洗一下手，”提艾诺说。“你的床上用品也是一样的。”