ABSTRACT
I. Introduction 159
II. Material and Methods 160
A. Studying the Children 160
Clinical Symptoms 161
Predisposing Factors 161
B. Studying the Animals 161
Ultrastructural Studies 161
Optical Microscopy 162
Scanning Electron Micrography 162
III. Results 162
IV. Discussion 164
Acknowledgment 167
References 167
I. Introduction
Contamination of the atmosphere is the most important factor affecting the
environment. Environmental pollution is recognized as a respiratory health
hazard and some epidemiological studies have focused on the prevalence of res-
piratory illnesses in adults and in children exposed to outdoor air pollution (1-3).
The initial studies by Lunn (4) and Melia (5) provided evidence that the number
of diseases was increasing in proportion to the poor quality of the atmosphere.
It appears that the elderly and infants are the most sensitive population groups (6).
Moreover, children may be more susceptible than adults because their organs are
still growing (7-9).
