How secondhand smoke exposure affects tobacco use and smoking susceptibility of adolescents: Sex and school differences

Introduction Secondhand smoke (SHS) exposure affects tobacco related health behaviors during adolescence and persists into adulthood. This study aimed to investigate the influence of SHS exposure on tobacco use among adolescents stratified by school and gender, and provide recommendations for controlling tobacco use in youth. Methods Through stratified random cluster sampling, 12278 selected students (aged 13-18 years) from schools in China were administered questionnaires. Multiple logistic regression was used to analyze whether SHS exposure would increase the smoking risk and susceptibility of adolescents. Results The prevalence of SHS exposure among the participating students was 74.8%. Adolescents exposed to SHS were at higher odds of being susceptible and currently smoking. Students with SHS exposure at both home and public places accounted for 36.6%, greatly increasing the current smoking risk and smoking susceptibility. Home SHS exposure had greater impact on the current tobacco use of boys (OR=2.13; 95% CI: 1.50-3.03) and junior school students (OR=4.67; 95% CI: 2.41-9.06). Exposure from public places increased the risk of current smoking in boys (OR=4.20; 95% CI: 2.31-7.65) and smoking susceptibility of vocational school students (OR=1.51; 95% CI: 1.07-2.15). Students with highlevel exposure to SHS had 2.25 times higher odds of e-cigarette use. Conclusions The prevalence of SHS exposure is still high among adolescents in China and is associated with increased risk for tobacco use regardless of gender and school level. Effective smoke-free strategies should be developed and strictly implemented. Boys and junior school students constitute vulnerable populations exposed to SHS at home.