Passive smoking and children's health: influence on lung function, aerobic capacity, and body mass index

Abstract

Introduction: Passive smoking (PS) is a significant public health problem, especially in children whose respiratory and immune systems are still developing. Although the harmful effects of tobacco smoke on adult health are well known, data on its simultaneous impact on lung function, aerobic capacity, and body mass index (BMI) in children are limited. The aim of this study was to assess the association of prenatal and postnatal exposure to passive smoking with these health indicators in children.

Methods: A cross-sectional study was conducted on 157 children aged 10 to 14 years (89 boys, 68 girls), students of the Elementary School "Trilj" in Trilj, Croatia. Exposure to PS was assessed using a structured questionnaire completed by children and parents. According to the smoking status of their parents, the subjects were divided into children exposed to PS and a control group. BMI was calculated using anthropometric measurements. Pulmonary function was assessed by spirometry (FVC, FEV1, FEV1/FVC, PEF), while aerobic capacity was assessed by the BEEP test. Descriptive statistics, t-test, Kruskal–Wallis test, χ² test, Spearman's correlation, and logistic regression were used for statistical analysis.

Results: 62.4% of children were exposed to passive smoking, with 61.2% already exposed to PP during pregnancy. Children exposed to PP, including prenatal exposure, had significantly lower FVC, FEV1, FEV1/FVC, and PEF values ​​compared to non-exposed children (p < 0.05). Also, a statistically significant increase in BMI was recorded in children exposed to PP. A lower level of aerobic fitness was associated with worse lung function and higher BMI. No significant differences were observed according to gender or level of physical activity.

Conclusion: Exposure to passive smoking, particularly during pregnancy and in the home environment, is associated with reduced lung function, poorer aerobic fitness, and increased BMI in children. The results highlight the need for stronger public health interventions aimed at reducing children's exposure to tobacco smoke and promoting smoke-free home environments.