Respiratory and cardiovascular functions among smoking and nonsmoking girls from two regions with different air pollution degree

Abstract

Aim: The aim of the present study was to analyze the respiratory and cardiovascular functions among smoking and nonsmoking girls attending two schools situated in regions with different levels of air pollution. The characteristic of air pollution is based on the data gathered by stations 1 and 2 belonging to the Uniform National System for Monitoring the Air Pollution in Bulgaria. The participants (n=108, 16.07+/-0.80 years) were separated in two groups: smokers (S1 - from school 1, S2 - from school 2) and nonsmokers (NS1 - from school 1, NS2 - from school 2). All of them performed pulmonary function testing and .cardiopulmonary exercise testing on a treadmill using our modification of the Balke protocol (Marinov et al., 2000). Reference values for European children, previously validated for the Bulgarian population, were used.

Results: There are no significant differences in mean levels of VC, IC, FEV1, MEF50 and MEF25 (as a percentage from the predicted value as well). The average level of the Tiffneau index is noticeably higher among nonsmokers from the two regions and is the lowest among smokers from the more polluted area, but a significant difference exists between S2 (88.7+/-5.9) and NS2 (92.6+/-4.7), p=0.047; T(L,CO)%pred: S1 (85.4+/-7.2) vs. S2 (86.7+/-8.2), p=0.048 and NS1 (88.3+/-8.2) vs. NS2 (92.8+/-14.5), p=0.037; V(E)%pred: S1 (127.5+/-9.6) vs. S2 (123.7+/-6.1), p=0.035; higher levels of total lung capacity (TLC%pred), S1 (107.3+/-9.2) vs. NS2 (104.3+/-9.1), p=0.009 and alveolar ventilation (VA), S1 (5.0+/-0.6) vs. NS2 (4.6+/-0.5), p=0.008.

Conclusions: 1. The negative effects of the combined influence of tobacco smoking and air pollution on some respiratory and cardiovascular functions of adolescent girls are more pronounced than each influence alone. 2. The cardiopulmonary exercise test gives adequate information about the combined effect of air pollution and smoking and using it for preventive purposes is an advisable method.