Outdoor/indoor/personal ozone exposures of children in Nashville, Tennessee

An ozone (O-3) exposure study was conducted in Nashville, TN, using passive O-3 samplers to measure six weekly outdoor, indoor, and personal O-3 exposure estimates for a group of 10- to 12-yr-old elementary school children. Thirty-six children from two Nashville area communities (Inglewood and Hendersonville) participated in the O-3 sampling program, and 99 children provided additional time-activity information by telephone interview. By design, this study coincided with the 1994 Nashville/Middle Tennessee Ozone Study conducted by the Southern Oxidants Study, which provided enhanced continuous ambient O-3 monitoring across the Nashville area. Passive sampling estimated weekly average outdoor O-3 concentrations from 0.011 to 0.030 ppm in the urban Inglewood community and from 0.015 to 0.042 ppm in suburban Hendersonville. The maximum 1- and 8-hr ambient concentrations encountered at the Hendersonville continuous monitor exceeded the levels of the 1- and 8-hr metrics for the O-3 National Ambient Air Quality Standard. Weekly average personal O-3 exposures ranged from 0.0013 to 0.0064 ppm (7-31% of outdoor levels). Personal O-3 exposures reflected the proportional amount of time spent in indoor and outdoor environments. Air-conditioned homes displayed very low indoor O-3 concentrations, and homes using open windows and fans for ventilation displayed much higher concentrations.