Electronic cigarette use and heavy metal exposure: Evidence from the Korea National Health and Nutrition Examination Survey

Purpose

This study investigated the association between electronic cigarette (e-cigarette) use and serum concentrations of heavy metals (lead, mercury, and cadmium) in the Korean population, utilizing data from the Korea National Health and Nutrition Examination Survey (KNHANES), a nationally representative cross-sectional survey.

Methods

Data from KNHANES 2013, 2016, and 2017 were analyzed. Participants were classified as e-cigarette users (individuals who had ever used e-cigarettes, including dual users who had also used conventional cigarettes), conventional smokers (individuals who had smoked at least 100 conventional cigarettes [5 packs], but not e-cigarettes, in their lifetime), and non-smokers (individuals who had never used e-cigarettes and either never smoked conventional cigarettes or smoked fewer than 100 cigarettes). Linear regression models were employed to evaluate the association between smoking status and heavy metal concentrations, adjusting for covariates including age, sex, income, education, and health behaviors. Subgroup analyses were performed based on sex, age, and obesity status.

Results

E-cigarette users exhibited significantly higher serum concentrations of heavy metals than non-smokers. Lead levels were 10.0 % higher (exponentiated β = 1.100; p < 0.001), mercury levels were 13.7 % higher (β = 1.137; p < 0.001), and cadmium levels were 61.4 % higher (β = 1.614; p < 0.001). Conventional smokers demonstrated elevated levels of these metals compared to non-smokers, but generally lower levels than e-cigarette users. Subgroup analyses revealed stronger associations among younger participants, males, and individuals with obesity, particularly for cadmium.

Conclusions

Dual use of e-cigarettes and conventional cigarettes is associated with elevated exposure to heavy metals compared to exclusive smoking cigarettes. These findings highlight the need for targeted public health interventions and stricter regulatory standards to address the risks associated with e-cigarette use.