Nitrous acid (HONO) is formed both indirectly from the reaction of nitrogen dioxide (NO2) with water on indoor surfaces, and directly during combustion.
This gaseous pollutant may be a previously unrecognized causal factor in assessments of nitrogen oxide exposure effects.
The present study is the first attempt to evaluate exposure effects of HONO on the human airways and the mucous membranes of the eyes and nose.
Fifteen healthy adult nonsmokers were exposed for 3.5 h in a double-blind, balanced protocol to clean air, 77, and 395 ppb HONO.
Each exposure was preceded by a 1-h baseline measurement period, and exposures were separated by 1 wk.
There was a 10-min exercise period during exposure.
Effects measurements included assessment of bronchial reactivity, measurement of specific airway conductance, spirometry, acoustic rhinometry, nasal lavage, tear-fluid cytology, a CO2 eye-provocation test, evaluation of eye redness, and subjective sensations.
Effects of HONO exposure on the eyes were found as exposure-related changes in tear-fluid cytology.
In particular, the number of squamous cells increased by 20,67, and 80% following exposure to clean air, 77, and 395 ppb HONO, respectively (p=0.004).
Possible indications of exposure effects on sensitivity to CO2 eye provocation and on specific airway conductance were also measured.
Mots-clés Pascal : Pollution air, Nitreux acide, Exposition, Voie respiratoire, Muqueuse, Oeil, Réactivité, Bronche, Volume pulmonaire, Lavage, Nez, Cytométrie, Exploration, Résultat, Homme, Larme, Appareil respiratoire, ORL
Mots-clés Pascal anglais : Air pollution, Nitrous acid, Exposure, Respiratory tract, Mucosa, Eye, Reactivity, Bronchus, Lung volume, Washing, Nose, Cytometry, Exploration, Result, Human, Tear, Respiratory system, ENT
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 95-0340488
Code Inist : 002B30A02A. Création : 01/03/1996.