Relationship between environmental exposures in children and adult lung disease: the case for outdoor exposures.

There is a growing understanding that chronic respiratory diseases in adults have their origins in early life. Adverse environmental exposures occurring in vulnerable periods during lung growth and development in the fetal period and in early childhood that alter lung structure and limit the growth in lung function may have lifelong consequences. Evidence is increasing that exposure to the ambient environment, including air pollutants, persistent toxic substances, water pollutants and respiratory viral infections, can inhibit lung function growth and predispose to chronic non-malignant lung diseases. These exposures generally interact with a genetic predisposition, and gene-environment interactions and epigenetic phenomena are attracting considerable study. An understanding of how ambient exposures impact on normal lung growth and development will aid in understanding of how chronic respiratory diseases of adults develop and may lead to new preventative strategies.