Acute exposure to acid fog : influence of breathing pattern on effective dose.
Concern about the possible adverse health effects of acid fog has been fed by two observations : air pollution disasters earlier in this century were typically associated with fog, and current samples of fog water can be strongly acid.
To study the acute effects of acid fog on the lung, the authors generated a monodisperse 10 mum MMAD aerosol of H2SO4 with a pH of 2.0 and a nominal concentration of 500 mug/M3.
They exposed seven healthy young men on alternate days to acid or control equiosmolar NaCl aerosol during 40 min of resting ventilation and 20 min of exercise ; the latter was sufficiently intense to induce oronasal breathing.
Exposure was by means of a head dome, a head-only exposure device that permitted continuous measurement (unfettered breathing) of VT, f, VE, and the onset and persistence of oronasal breathing.
In this article the authors compare the relative importance of parameters contributing to the between-subject variability in estimated hydrogen ion dose to the lower airways (HLAW+), based on analysis of variance.
Physiologic parameters accounted for 70% of the variability, of which 34% was due to differences in duration of oronasal breathing (tON) and 36% to differences in ventilation rate during oronasal breathing (VE (ON)) ; inhaled hydrogen ion concentration [H+], the environmental parameter, contributed only 30%
Mots-clés Pascal : Pollution air, Brume acide, Brouillard, Toxicité, Homme, Appareil respiratoire pathologie, Poumon, Rythme respiratoire, Dosimétrie, Volontaire, Inhalation, Aérosol, Transport mucociliaire, Sulfurique acide
Mots-clés Pascal anglais : Air pollution, Acid mist, Fog, Toxicity, Human, Respiratory disease, Lung, Breathing rate, Dosimetry, Volunteer, Inhalation, Aerosols, Mucociliary transport, Sulfuric acid
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 95-0149551
Code Inist : 002B03M02. Création : 09/06/1995.