Association between Secondhand Smoke and Allergic Diseases in Korean Adolescents: Cross-Sectional Analysis of the 2019 KYRBS

This study aimed to determine whether secondhand smoking (SHS) in adolescents is associated with allergic diseases. Data from the 2019 Korea Youth Risk Behavior Survey were used (N = 37,848 Korean adolescents: 19,114 boys and 18,734 girls). This study assessed SHS exposure using questionnaire data, which included information, such as exposure to SHS and allergic diseases. Multiple logistic regression analysis was used to estimate the association between exposure to SHS and allergic diseases. The results showed that exposure to SHS in schools and public places, exposure for 1–3 days (OR = 1.158, 95% CI, 1.077–1.246), 4–6 days (OR = 1.308, 95% CI, 1.190–1.438), and everyday (OR = 1.306, 95% CI, 1.187–1.437), and exposure in one, two, or three places were significantly associated with allergic diseases (one OR = 1.226, 95% CI, 1.169–1.128, two OR = 1.289, 95% CI, 1.222–1.360 and three OR = 1.282, 95% CI, 1.177–1.395). The present results show that exposure to SHS occurs in various places and at various frequencies, and it is associated with allergic diseases in Korean adolescents.