Most people believe that regular hand-washing is the best way to prevent infections. And they’re right: hand-washing does prevent certain infections, but too much washing can actually help some infections along.What’s going on?
很多人认为经常洗手是预防感染的最佳方法。他们是对的：洗手是可以预防某些感染，但是过多的清洗会滋生细菌。这是怎么回事呢？
Right now, there are millions of bacteria from hundreds of different species happily residing on your hands, not to mention your teeth, gums, eyes and ears. These bacteria are either transients or residents. Washing your hands helps remove transientbacteria that are just visiting from foreign places like the sink, doorknob and even other people’s hands. Washing shouldn’t remove your hands’ own resident bacteria,though.
此时此刻，你的手上有成千上万不同品种的细菌，更不用说你的牙齿，牙龈，眼睛和鼻子了。这些细菌既不是暂住者也不是寄宿者。洗手能够帮助清洗掉短暂细菌，比如来自水槽，门把手或者其他人的手。可是，洗手不会清除手上的寄生细菌的。

While it’s hard to imagine your hands as a bacterial homeland, these residents are perfectly normal and are important in maintaining your health. They help prevent transientbacteria from settling in, and each resident keeps other residents from overpopulating.
虽然很难想象你的手是细菌的家园，但这些细菌是非常正常的，同时它们对维护你的身体健康有着重要的作用。它们能够防止暂住细菌定居，保持整个细菌数量的平衡。
If you scrub your skin too frequently, especially with anti-bacterial soap, you could upset resident bacteria, leading to the overpopulation of certain species and local skin infections. Scrubbing away residents might also let transients move in and cause disease. Finally, over washing could break down the skin itself. This allows harmless skin residents to go beneath the skin, where they can become dangerous transients.
如果你过于频繁地擦洗皮肤，特别是用过抗菌香皂，就可能会打乱寄生细菌的平衡，从而导致某种细菌过剩引起皮肤过敏。洗掉寄生细菌也有可能会让暂住细菌进入定居引起疾病。最终，过度清洗导致皮肤健康垮掉。这会致使无害的皮肤寄生细菌进入皮肤内，在那儿它们可能成为危险的暂住细菌。
So, while a good wash with soap and water is still a great idea, overwashing might lead to some unpleasant symptoms, not to mention inflamed and unsightly hands.
因此，尽管用香皂洗手是很好的做法，可是，过多的清洁也许会导致一些令人不悦的症状，更不用说发炎难看的手了。