Background & objectives: Exposure to environmental tobacco smoke (ETS) can lead to airflow limitation, similar to that seen in smokers. However, the effects have not been conclusively proven. In the present study an attempt was made to characterize the effect of ETS exposure at home on airflow mechanics in asymptomatic healthy women.
Methods: Fifty women volunteers with no apparent health related problem, exposed to household ETS (group I), and 50 age-matched women not exposed (group II) were studied. Vital capacity (VC), forced expiratory flow in first second (FEV1), FEV1/VC ratio, peak expiratory flow (PEF), maximal midexpiratory flow (FEF(25-75%)), airway resistance (R(aw)) and specific airway conductance (sG(aw)) were measured, and compared between the two groups. Conditional logistic and linear regression analysis were done to assess contribution of household ETS exposure to decreased lung function.
Results: FEV1 and PEF values were marginally lower among women in group I (mean difference 0.13 l and 0.20 l/sec respectively). FEF(25-75%), R(aw) and sG(aw) were significantly impaired in this group. Ten (20.0%) women in group I and five (10.0%) in group II had abnormal R(aw) (adjusted odds ratio 6.72, 95% confidence limits 1.15-39.42), while eight (16.0%) women in group I and one (2.0%) in group II had abnormal sG(aw) (adjusted odds ratio 21.08, 95% confidence limits 1.30-341.05). Cumulative life time ETS exposure was, not significantly related to a reduction in FEV1, VC, PEF, FEF(25-75%), R(aw) or sG(aw) after adjustments for potential confounders.
Interpretation & conclusion: Exposure to household ETS resulted in subtle impairment of airflow mechanics in asymptomatic women, possibly attributed to small airway narrowing. Further investigations are required to study the progression of this impairment with time.