Comparison of urine heavy metals in exclusive menthol and non-menthol cigarette users by race/ethnicity: The 2015–2016 National Health and Nutrition Examination Survey Special Sample

INTRODUCTION: The objective of this study was to investigate the differences in urine concentrations of heavy metals (uranium, cadmium, and lead) between exclusive menthol and non-menthol cigarette smokers across three racial/ethnic groups using data from the National Health and Nutrition Examination Survey (NHANES) 2015–2016 Special Sample. METHODS: Data from NHANES 2015–2016 Special Sample were analyzed to assess the association between menthol smoking and heavy metal biomarkers in urine across three racial/ethnic groups (N=351), including Non-Hispanic White (NHW), Non-Hispanic Black (NHB), and Hispanic/Other (HISPO). Multivariable linear regression models were used to estimate adjusted geometric means (GMs) and ratio of GMs (menthol/non-menthol smokers) (RGMs) for urine biomarkers of heavy metals between menthol and non-menthol smokers by race/ethnicity. RESULTS: Among the 351 eligible participants, 34.4% (n=121) were NHW, 33.6% (n=118) were NHB, and 32.0% (n=112) were HISPO exclusive cigarette smokers. The analysis revealed significantly higher concentrations of urine uranium in NHB menthol smokers compared to NHB non-menthol smokers (RGMs=1.3; 95% CI: 1.0–1.6; p=0.04). NHW menthol smokers appeared to have higher levels of urine uranium than non-menthol smokers, but the difference was not statistically significant (9.0 vs 6.3; RGMs=1.4; 95% CI: 1.0–2.2; p=0.08). There were no significant differences in urine metals (cadmium and lead) by menthol status among NHW, NHB, or HISPO cigarette smokers (p>0.05). CONCLUSIONS: The research findings regarding the higher levels of urine uranium among Non-Hispanic Black (NHB) menthol cigarette smokers raise questions about the claims suggesting that additives in cigarettes do not contribute to increased toxicity.