To explore this further, the researchers drew on 8022 child participants in the Tasmanian Longitudinal Health Study (TAHS), all of whom had tests to assess their lung function (spirometry). These included spirometry to assess two measures of lung function (FEV 1 and FVC), as well as questionnaires on demographics and respiratory symptoms/disease. More than two-thirds of the fathers (nearly 69%) and more than half of their children (56.5%) had been exposed to passive smoking during their childhoods. But children whose fathers had been exposed to passive smoking as a child were twice as likely to have below-average FEV 1 if they, too, had been exposed to passive smoking during their childhood. “This is of importance from a public health perspective, as passive smoke exposure affects about 63% of adolescents, which is significantly higher than the approximately 7% affected by active smoking.