It can form free radicals and is thus a powerful oxidant. Exposure to elevated ozone concentrations can disrupt the barrier function of the lung, alter mucociliary bronchoalveolar clearance, the function of alveolar macrophages, and immune competence. These effects increase susceptibility to bacterial respiratory infections and lessen lung function. 1,2 Most studies of the health effects of ozone have focused on the respiratory system. As the concentration of ozone increases, there is an increase in symptoms such as cough, nasal irritation, throat irritation, chest pain with deep inspiration, shortness of breath, and decreased exercise performance.
Ozone causes increased airways responsiveness and sensitivity to allergens.
Effects in Healthy Individuals . The influences of duration of exposure and level of activity can be seen in Table 1. The FEV 1 decreases by about 50 ml for every 0.1 ppm of ozone exposure. Fortunately, the decreased lung function is of short duration and reversible in healthy individuals, but it is not known whether repeated short-term exposure to ozone can permanently injure the lungs. Effects in Sensitive Individuals .