safe exposure level的意思|示意

Really, the safe level of exposure is no exposure.

吸烟真正的安全水平就是一点儿都不吸。

There is no safe level of exposure to second-hand tobacco smoke.

关于二手烟草烟雾，不存在安全接触水平。

"When you look at the biology, there is no safe level of exposure to tobacco smoke," he says.

他还说：“当你看了生物学以后就会发现，任何级别的烟雾含量都是不安全的。”