title: Human activities that may lead to high inhaled intake doses in children aged 6-13.
abstract: This paper focuses on possible activities of children aged 6-13 that may make them susceptible to high hourly intake doses of ozone (O(3)) air pollution. Data from an O(3) exposure modeling exercise indicates that relatively few hours can account for a significant amount of the total cumulative ozone intake dose (D(I)(T)) received in a year. While O(3) concentration levels affected the hourly intake dose (D(Ih)) more than breathing rate (V ̇ (E)), there was a distinct and significant relationship between V ̇ (E) and D(Ih) when hours in a year were stratified by concentration levels. By investigating the V ̇ (E) levels associated with high dose hours, it appears that activities with an hourly V ̇ (E) rate of between 25 and 45 l/min can lead to high intake doses of O(3). The exercise literature was reviewed to ascertain which activities could lead to that range of V ̇ (E)'s and be sustained by children for 1 h. A list of such activities was developed. If an analyst is interested only in modeling high D(Ih) hours for children aged 6-13, an efficient approach might be to focus on those activities and estimate D(I)(T) for the other hours in an aggregated manner.
authors.affiliation: Risk and Exposure Assessment Group, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
authors.forename: T
authors.initials: T
authors.lastname: McCurdy