Figure 5: Effects of ozone on lung function.Ozone reduces the maximal inspiratory position (at the left of the curves) and may slightly increase the residual volume (at the right). Reduction in maximum inspiration reduces forced vital capacity (FVC), and this causes a reduction in expiratory flow measurements, such as flow at 50% of FVC expired (FEF50%). Because ozone causes only a relatively small increase in airway resistance, the relationship between flow and volume is not changed to a large extent. Source: Devlin et al. (1997)