Effectiveness of government anti-smoking policy on non-smoking youth in Korea: a 4-year trend analysis of national survey data

OBJECTIVES Since the Health Promotion Act was introduced in Korea in 1995, anti-smoking policies and regulations have undergone numerous revisions, and non-smoking areas have gradually been expanded. The purpose of this study was to examine the impact of a partial legislative ban on adolescent exposure to secondhand smoke using objective urinary cotinine levels in a nationwide representative sample. METHODS Urine cotinine levels were measured in the Korea National Health and Nutrition Examination Survey from 2008 to 2011. This study was a trend analysis of 4 years of national survey data from 2197 Korean youth aged 10-18 years. Among non-smokers, the 75th percentile urinary cotinine level was estimated. We also considered the number of household smokers. RESULTS The 75th percentile urine cotinine level of non-smokers showed a significant decreasing trend from 2008 to 2011, from 15.47 to 5.37 ng/mL, respectively. Urine cotinine did not decline significantly in non-smokers living with smokers during the study period. The results did not show a statistically significant reduction in smoking rate in adolescents from 2008 to 2011, although there was a trend towards a decrease (p=0.081). CONCLUSIONS Based on urine cotinine levels, government-initiated anti-smoking policies have only been effective among highly exposed non-smoking adolescents during the study period. Further study needs to evaluate whether or not the legislative ban affects domestic smoking exposure.