Exposure to air pollution has been linked to increased cardiorespiratory morbidity and mortality. The exact component of air pollution that mediates this effect is unknown, but the link is strongest for fine combustion derived particulate matter derived from traffic sources. It has been demonstrated that inhalation of diesel exhaust impairs vascular vasomotor tone and endogenous fibrinolysis. Recent studies using an inline retrofit particle trap to reduce the particulate component of exhaust have shown that filtering particles leads to a reversal of the endothelial dysfunction seen after diesel exhaust exposure, and have even suggested an augmentation of vascular function. This raises the question of the cardiovascular effects of the gaseous pollutants, the most abundant of which is nitrogen dioxide. In this study we plan to investigate the cardiovascular effects of nitrogen dioxide exposure.

Inclusion Criteria:

• Healthy male volunteers

Exclusion Criteria:

• Current smokers
• Significant occupational exposure to air pollution
• Regular medication use
• Intercurrent illness