ABSTRACT
Asthma is a disease characterized by intermittent bronchoconstriction due to increased airway responsiveness to both allergic and nonallergic stimuli. Airways inflammation is a key underlying feature of this disease. Evidence has been emerging over the last 3–4 years that air pollution, specifically traffic-related air pollutants, may be contributing to new-onset asthma. The evidence suggests that in addition to air pollution acting as an exacerbating agent, air pollutants, particularly traffic-related ones, may be contributing to the development of new-onset asthma. To understand how oxidant pollutants such as ozone, or biological/bacterial-based pollutants such as endotoxin affect the biology of asthma, it is important to appreciate the constitutive state of the asthmatic airway prior to exposure in terms of inflammation, immunology, and physiology. Evidence from epidemiology and cohort-based studies establishes a clear link between exposure to air pollution and asthma exacerbation, and supports a growing trend that traffic-related air pollutants can act as causal agents in the development of new-onset asthma.
