Exposure and Risk Assessment of Second- and Third-Hand Tobacco Smoke Using Urinary Cotinine Levels in South Korea

Abstract

Exposure to environmental tobacco smoke (ETS) is the reason for approximately 1% of global mortality. ETS exposure can happen either as inhalation of direct cigarette smoke (second-hand smoke) or its associated residue particles (third-hand smoke), especially when living with a smoker in the same family. This study investigated the association between the urinary cotinine levels, as biomarkers of exposure to tobacco smoke, of smokers and those exposed to second-hand and third-hand smoke while living in the same family, through a Korean nationwide survey. Direct assessment of ETS exposure and its lifetime effect on human health is practically difficult. Therefore, this study evaluated the internal estimated daily intake (I-EDI) of nicotine and equivalent smoked cigarette per day (CPD). The carcinogenic and non-carcinogenic inhalation risks of ETS exposure were assessed by considering the calculated equivalent CPD and composition of cigarette smoke of high-selling cigarette brands in South Korea. The results show that there is a statistically significant positive correlation between the cotinine levels of smokers and those of the non-smokers living in the same family. The risk assessment results yielded that hazard index (HI) and total excess lifetime cancer risk (ECR) for both second-hand and third-hand smoke exposure can exceed 1 and 1 × 10^-6, respectively, especially in women and children. In the composition of the cigarette smoke, 1,3-butadiene and acrolein substances had the highest contribution to HI and ECR. Consequently, the provision of appropriate plans for smoking cessation as a strategy for the prevention of ETS exposure to women and children is deemed necessary.

Keywords: cotinine; environmental tobacco smoke; excess lifetime cancer risk; hazard index; second-hand smoke; third-hand smoke.

Figure 1

Condition of urinary NNAL and cotinine in (a) positive control (active smokers) and (b) non-smoker subjects.

Figure 2

Correlation of urine cotinine levels of active and passive smokers living in the same family according to the age of the passive ETS exposure subjects: (a) all ages, (b) adults (age ≥19), (c) adolescents (ages 12–18), and (d) children (ages 6–11).

Figure 3

Assessment of hazard quotient for the composition of cigarette smoke to SHS exposure subjects based on age: (a) 6–10 years old, (b) 11–13 years old, (c) 14–18 years old, and (d) 19 years old and above.

Figure 4

Assessment of hazard quotient for the composition of cigarette smoke to THS exposure subjects based on age: (a) 6–10 years old, (b) 11–13 years old, (c) 14–18 years old, and (d) 19 years old and above.

Figure 5

Assessment of excess lifetime cancer risk for the composition of cigarette smoke to SHS exposure subjects based on age: (a) 6–10 years old, (b) 11–13 years old, (c) 14–18 years old, and (d) 19 years old and above.

Figure 6

Assessment of excess lifetime cancer risk for the composition of cigarette smoke to THS exposure subjects based on age: (a) 6–10 years old, (b) 11–13 years old, (c) 14–18 years old, and (d) 19 years old and above.

Figure 7

Assessment of (a) hazard index and (b) total excess lifetime cancer risk for the composition of cigarette smoke to ETS exposure subjects based on age.