National scale air toxics assessment respiratory hazard index:NFr:Pt:^Patient:Qn
national scale air toxics assessment respiratory hazard index:nfr:pt:^patient:qn
National scale air toxics assessment respiratory hazard index:Number Fraction:To identify measures at a point in time:^Patient:Quantitative
national scale air toxics assessment respiratory hazard index:number fraction:to identify measures at a point in time:^patient:quantitative