There is renewed interest in inhalation toxicology regarding 'susceptibilit
y' as associated with host variables, including genetics, age, diet, and di
sease. This interest derives from epidemiology that shows air pollution-rel
ated human mortality/morbidity, especially among individuals with cardiopul
monary disease. Several animal models with experimental or genetically-base
d cardiopulmonary diseases are now being incorporated into inhalation toxic
ology studies to investigate mechanisms that underlie host susceptibility.
However, current models have strengths and limitations as to how they mimic
the essential features of human diseases. To date, animal models of pulmon
ary hypertension, bronchitis, asthma, and cardiovascular disease; but not e
mphysema, appear to exhibit greater susceptibility to air pollution particu
late matter. As in humans, host susceptibility appears to involve multiple
genetic and environmental factors, and is poorly understood, but the databa
se of information is growing rapidly. As existing models gain wider use, ou
r understanding of the models will improve and encourage refinements/develo
pment of models that integrate both genetic and environmental factors to be
tter mimic the human condition. (C) 2001 Elsevier Science B.V. All rights r
eserved.