Enhanced sensitivity of the postnatal lung to environmental insults and oxidant stress.

Examination of the current state of health in the United States suggests that childhood lung diseases are increasing at an alarming rate. Looking more closely at the data, it can be seen that this increase is especially true for chronic respiratory diseases such as allergic asthma. This is a disease that is thought to have its roots in childhood insults. The demographics of the current wave of asthma and other chronic lung diseases reveal that the incidence is highest among children in polluted inner cities, where it seems to have reached epidemic proportions. This gives rise to a number of serious questions as to causality. Has the nature of the urban environment changed to such an extent as to lead to increased disease? Are current populations more sensitive to existing environmental insults? Is the increase real, or has our ability to detect it improved? This article addresses the possibility that factors intrinsic to the lung and its development have combined with specific environmental risk factors to have an adverse impact on children's health.