1. the airway mucosa. This response can be an effort by the Iung to neutralize and
2. described as graded in that it seems to be remove the offending stimulus to minimize
3. proportional to the magnitude of the stimu- tissue injury. In this light it is somewhat
4. lus and its duration. Thus a minor or brief ironic that this protective mechanism can
5. irritant exposure may produce a localized itself be both a target of inhaled pollutants