Human Biological Responses to Low Level Ozone

To investigate if low level ozone exposure will cause measurable inflammation in nasal cells.

Air pollutants including ozone have been implicated in affecting health outcomes. In particular, high level ozone exposure has been shown to affect pulmonary function and cause pulmonary inflammation. Troubling community-based work has implicated high ozone levels as being correlated with increased pediatric asthma emergency room visits. Because of adverse health effects, EPA standards for safe ozone levels have been set, currently at 0.07 ppm. Still, it is estimated that 100 million Americans live in areas where ozone levels periodically remain above the EPA standard. And while this EPA standard had been set based on available data, it remained unclear at the time whether naturalistic low-level ozone exposure, such as fluctuations between 0.06-0.08 ppm throughout the day, might affect health as well. This group previously examined lung function and inflammatory response in adults exposed to low-level ozone, 0.06 ppm exposure for 6.6 hours, while undergoing intermittent moderate exercise. The investigators found that in response to low-level ozone exposure (0.06 ppm) with exercise, lung function declines and neutrophilic airway inflammation is observed. What remains unclear, is whether low-level ozone alone - without exercise - will cause similar health effects. To mimic exposure to ozone on a typical summer day in a polluted city, the investigators will expose subjects to a varying level of ozone, form 0.06 ppm to 0.08 ppm, rather than a constant 0.07ppm. The variation from 0.06ppm to 0.08ppm, then back to 0.06ppm will occur each hour.