Development and Testing of a Time-Resolved Personal Ozone Monitor.

摘要

Ground-level ozone is a common urban pollutant that has been linked to various health problems. Due to measurement challenges, not many experimental studies on personal ozone exposure have been conducted that provide time-resolved concentration data. In this research project, a new personal ozone monitor was built that provides increased temporal resolution. The monitor also measures temperature, relative humidity and location via GPS. Six monitors were built, calibrated and tested. Calibrations of the monitor showed a linear response to varying ozone concentration. Side-by-side comparison of the monitors showed reasonable correlations but revealed some issues with consistency across monitors. A major issue with the monitor was that it had poor or no detection at ozone levels at or below 20 ppb, which limited its usefulness.;To examine the feasibility of using the monitors in personal exposure studies, they were deployed in a small pilot study focusing on the personal ozone exposure of senior citizens. As a group, senior citizens are believed to be susceptible to health problems if they are exposed to elevated ozone concentrations. Understanding exposure patterns in older adults is important in interpreting health effects of ozone and in designing mitigation strategies.;The monitors were deployed for a pilot study conducted in Arvada, Colorado. The study was done in two five-day periods, with a six hour testing time frame between 11am and 5pm, during July and August of 2011. The volunteers were also given an activity diary, in which they recorded the amount of time they spent indoors, outside and in transit. The results from the ozone monitors were then compared to the Arvada stationary monitoring site to observe the difference between levels of personal exposure versus levels recorded at monitoring sites. The results from the study were inconclusive due to the majority of the data being below detection levels or in error. More development is needed to improve the sensor performance at lower detection limits before it can be deployed for exposure studies.