Cardiovascular function and ozone exposure: The Multicenter Ozone Study in oldEr Subjects (MOSES)

Area of Science:

• Environmental Health
• Cardiovascular Science
• Toxicology

Background:

• Observational studies link ambient ozone to cardiovascular events and mortality.
• Limited research exists on acute cardiovascular responses to controlled ozone exposure.

Purpose of the Study:

• To investigate the acute cardiovascular effects of controlled ozone inhalation in healthy older adults.
• To test the hypothesis that ozone exposure induces autonomic imbalance, repolarization abnormalities, arrhythmia, and vascular dysfunction.

Main Methods:

• Randomized crossover study with 87 healthy volunteers (55-70 years).
• Exposure to 0, 70, and 120 ppb ozone for 3 hours with intermittent exercise.
• Comprehensive cardiovascular endpoints measured before, during, and after exposure.

Main Results:

• No significant effects of ozone exposure on autonomic function, repolarization, ST segment, arrhythmia, or vascular function.
• Systolic blood pressure and flow-mediated dilation remained unaffected.

Conclusions:

• Three-hour exposure to relatively low-level ozone did not demonstrate acute cardiovascular effects in this cohort.
• Potential effects at higher concentrations, longer durations, or in vulnerable populations cannot be ruled out.
• Pre-existing exposure to ambient pollutants may have influenced biomarker responses.