你知道吗？其实你洗澡时用的淋浴头并没有你所想象得那么干净，甚至可能布满了细菌。由于淋浴头的内部环境经常在潮湿和干燥之间交替并且很少受到外部环境影响，因此非常适合微生物的繁殖。虽然大多数人并不需要担心会因为不干净的淋浴头而染上疾病，但定期清洁淋浴头并去除其中的水垢对我们的健康是有益的。本文浅谈淋浴头中隐藏的健康隐患。

词汇：shower 淋浴

1 This is a city like no other. An invisible army of microbes live here, including bacteria, fungi, moulds and mites, and it's the one place you'd have hoped would be clean – your showerhead.

2 If you unscrew it and take a peek inside, you might be surprised as to what you find – quite possibly a slimy dark biofilm. When you switch on the shower, it's not just steam and water that come out, but a blast of microbes as well. Rob Dunn, an evolutionary biologist from North Carolina State University, calls showerheads extreme environments because they are either bone-dry or soaking wet. Once you've showered, the head remains warm and dries out undisturbed, creating the perfect ecosystem for bacteria to feed on dissolved nutrients from the water.

3 It seems the majority of us don't need to worry about catching a bug from having a shower though. "Only showers contaminated with Legionella and other opportunistic pathogens pose a risk," says Frederik Hammes, a drinking water microbiologist at the Swiss Federal Institute of Aquatic Science and Technology in Switzerland. Meanwhile, one study in the US found that warmer areas, like Florida and Hawaii, with higher chlorine levels tend to have more pathogenic mycobacteria, which can lead to higher rates of a chronic lung infection called non-tuberculous mycobacteria (NTM) lung disease. This is likely because the showerhead has less time to dry out in more tropical climates, so bacteria can grow more easily.

4 Even if becoming ill from your showerhead is highly unlikely, you'd probably still like to reduce the number of bacteria coming out when you're trying to get clean. One study found that the spray pattern of your shower makes a difference – mist mode spreads NTM cells a lot more than a massage or rain showerhead, for example. Higher temperatures have also been shown to spread microbes more easily. The best way to keep bacteria away though is to regularly clean your showerhead by descaling it or soaking it in lemon juice.

5 Since we can't fully eradicate the microbes in our showers, and we like to stay clean, we'll have to learn to coexist with them.

测验与练习

一、为本文选择总结句。

1. Which statement best summarises the article?

a. Showerhead microbes generally originate from human skin cells rather than the water supply.
b. The likelihood of catching a disease is higher if you live in a cool climate.
c. Microbes in your shower head are generally safe for most people.

二、根据文章内容选出正确的选项。

1. Why is it easy for microbes to build up in a showerhead?
a. Because microbes thrive in damp undisturbed environments.
b. Because hot water encourages bacteria to multiply.
c. Because dissolved nutrients can't leave the showerhead.

2. Showers contaminated with Legionella can be deadly.
a. True
b. False
c. Not given

3. Pathogenic mycobacteria is most likely to be found in…
a. a cool environment with high-chlorine levels in the water.
b. a warm environment with high-chlorine levels in the water.
c. a warm environment with low-chlorine levels in the water.

4. Which spray pattern is the worst for spreading NTM cells?
a. mist
b. massage
c. rain

5. What does 'it' refer to in the following sentence? The best way to keep bacteria away though is to regularly clean your showerhead by descaling it...
a. bacteria
b. your shower
c. your showerhead

三、用下列单词完成对本文的总结。

Look inside your showerhead and you might see a 1) _______ film that's full of bacteria. These are the perfect 2) _______ for 3) ________. But you're unlikely to catch a bug unless your showerhead is 4) _______ with Legionella or another dangerous 5) ________.

contaminated
mist
microbes
pathogen
dry out
environment
slimy

（答案见词汇表后）

词汇表

microbe 微生物
mite 螨虫
showerhead 淋浴头
unscrew 拧开
slimy 黏黏糊糊的
biofilm 生物膜
blast 一大股
extreme environment 极端环境
bone-dry 完全干燥的
dry out 逐渐干燥
catch a bug 生病
Legionella 军团菌
opportunistic 投机的
pathogen 病原体
drinking water 饮用水
chlorine 氯
tropical climate 热带气候
spray pattern 喷流模式
mist 雾
descale 去除水垢

答案

一、为本文选择总结句。

c. Microbes in your shower head are generally safe for most people.

二、根据文章内容选出正确的选项。

1. a. Once you've showered, the head remains warm and dries out undisturbed, creating the perfect ecosystem for bacteria to feed on dissolved nutrients from the water.

2. c. Not given. "Only showers contaminated with Legionella and other opportunistic pathogens pose a risk,"… 'Deadly' is not mentioned, only a 'risk'.

3. b. Meanwhile, one study in the US found that warmer areas, like Florida and Hawaii, with higher chlorine levels tend to have more pathogenic mycobacteria…

4. a. …mistmodespreads NTM cells a lot more than a massage or rain showerhead…

5. c. The best way to keep bacteria away though is to regularly clean your showerhead by descaling it…

三、用下列单词完成对本文的总结。

Look inside your showerhead and you might see a slimy film that's full of bacteria. These are the perfect environment for microbes. But you're unlikely to catch a bug unless your showerhead is contaminated with Legionella or another dangerous pathogen.