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The chemical neutralization of inhaled sulfuric acid aerosol
Author(s) -
Larson Timothy,
Frank Robert,
Covert David,
Holub Dick,
Morgan Michael
Publication year - 1980
Publication title -
american journal of industrial medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.7
H-Index - 104
eISSN - 1097-0274
pISSN - 0271-3586
DOI - 10.1002/ajim.4700010323
Subject(s) - neutralization , sulfuric acid , inhalation , aerosol , medicine , respiratory system , micrometer , formaldehyde , environmental chemistry , anesthesia , chemistry , immunology , inorganic chemistry , organic chemistry , physics , antibody , optics
We hypothesize that gaseous ammonia (NH 3 ) released into respiratory airways can neutralize inhaled acidic particles and alter or mitigate their toxicity. To test this hypothesis, we have examined the relationship between respiratory NH 3 and the chemical neutralization of inhaled sulfuric acid (H 2 SO 4 ) aerosol in the surgically isolated upper airways of anesthetized dogs. With air entering via the mouth, the NH 3 concentration measured at the larynx, ranged between 30 and 225 parts per billion (ppb). The extent of neutralization at this point ranged from 8%‐70% (n = 16) for the 0.5‐μm particles and 7%‐22% (n = 6) for the 1.0‐μm particles. With air entering via the nose, the laryngeal NH 3 concentration ranged between 50 and 220 ppb. Neutralization values were between 15%‐65% (n = 8) for 0.5‐μm particles, and between 16%‐18% (n = 3) for 1.0‐μm particles. For both routes of entry, the extent of neutralization was correlated with the laryngeal NH 3 concentration. We conclude that the chemistry of acidic particles is significantly altered by respiratory NH 3 during inhalation. The extent of neutralization is related to both the NH 3 concentration in the airway and the size of the particle entering the airway. The extent of neutralization per ppb of laryngeal NH 3 is related to the route of entry, being greater for the mouth than the nose.