英语听力文摘 English Digest 478、日光浴床安全吗？（在线收听）

Are Tanning Beds Safe?

Millions of people go to tanning salons, some to get a base tan before they go away on a beach vacation. The idea of the base tan is that it will protect you from burning on your sun excursion, so that what you end up with is a darker tan rather than a lobster face and discomfort.

But does a base tan protect your skin from ultraviolet damage you can’t see? And how safe are tanning beds themselves?

The Truth About Tanning

Dermatologists say that just one trip to the tanning salon can produce DNA damage that can cause skin cancer. Tanning booths emit about ninety-five percent ultraviolet A light and five-percent ultraviolet B light.

For some time, ultraviolet A light was thought to affect the aging of skin only. Now dermatologists know that ultraviolet A light, like ultraviolet B light, also causes genetic damage linked to skin cancer.

One study indicated that people who used tanning beds at least once were two-and-a-half times more likely to develop squamous cell skin cancer, and one-and-a-half times more likely to develop basal cell skin cancer. Tanning bed users are at an increased risk of melanoma too, the deadliest form of skin cancer.

Skin Cancer And SPFs

Not only can tanning inside lead to skin cancer, but the base tan that indoor tanning provides contains a sun protective factor of only about SPF-4. It doesn’t offer good protection against sunburn or the genetic damage that can lead to skin cancer. Dermatologists recommend an over-the-counter sunscreen of SPF-15 or higher.

数百万的人在海滨度假之前去日晒沙龙，一些人的皮肤会晒成棕褐色。把皮肤晒成棕褐色，是因为它可以保护你免于晒伤，因此最终你的皮肤将变得更黑，而不是变红或是感觉不舒服。

但是棕褐色皮肤真的可以使你的皮肤免遭那些你看不见的紫外线伤害吗？

日光浴的真相

皮肤病学家称仅仅去一次日晒沙龙就可以引起致皮肤癌的DNA损害。人工日光浴场放射出约95%的紫外线A光和5%的紫外线B光。

有时，人们认为紫外线A光仅仅是影响皮肤老化。现在皮肤病学家们认识到，和紫外线B光一样，紫外线A光也会产生与皮肤癌有关的遗传性伤害。

有研究表明，至少用过一次日光浴床的那些人得鳞状细胞皮肤癌的可能性要（比没用过的）高2.5倍，得基底细胞皮肤癌的可能性要高1.5倍。日光浴床使用者得黑素瘤的风险也增加了，这是一种最致命的皮肤癌。

皮肤癌和防晒系数

日光浴不仅在内部能让人体得皮肤癌，而且即使是室内日光浴提供的“日晒”防晒系数也只有SPF4.它们没有提供良好的保护以免受致皮肤癌的晒伤或遗传性伤害。皮肤病学家们推荐使用防晒系数15或更高的非处方防晒霜。