Effects of air pollutants on the allergic response.
There is strong evidence that the prevalence and severity of allergy are increasing in many areas of the world. Pollutants have been implicated as one of the important factors responsible for these observations because they have been shown to act at multiple steps in the allergic response. They can increase immunoglobulin E (IgE) synthesis and potentiate the specific IgE response to antigens. Pollutants also are capable of inducing a primary specific IgE response to an antigen and increase allergic airway inflammation. In addition, pollutants can induce airway inflammation or cause nonspecific irritation. Pollutants also are capable of modulating the allergenicity of airborne substances, which possibly may promote allergic sensitization.