Ammonia in the human airways: neutralization of inspired acid sulfate aerosols

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Science  08 Jul 1977:
Vol. 197, Issue 4299, pp. 161-163
DOI: 10.1126/science.877545


In the human being, expired ammonia concentrations from 7 to 520 micrograms per cubic meter are controlled by the last airway segment traversed by the air, and such concentrations are higher in the mouth than nose. Inspired submicrometric sulfuric acid aerosol at a mass concentration of 600 +/- 100 micrograms per cubic meter was found to be an ammonium salt with an average ammonium to sulfate molar ratio of greater than or equal to 1, when sampled within 0.5 second after exhalation.