The Exposure to Metals from ECigarettes (EMIT) Study

Lead PI: Ana Navas-Acien

Unit Affiliation: Mailman School of Public Health

September 2018 - June 2021
Project Type: Research

DESCRIPTION: E-cigarettes expose users to metals, since a metal coil is used to generate aerosol and most coils are composed of nickel and chromium, which are known inhalation carcinogens. A new e-cigarette type called POD is growing in popularity with unknown potential for exposure. The goal of this study is to evaluate how e-cigarette use patterns impact exposure to toxic metals. Study aims are: (1) to understand the role of metal heating components on the transfer of metals into the aerosol, by analyzing metal concentrations in e-liquid before it is in contact with the heating coil, and in the aerosol generated; (2) to characterize patterns of e-cigarette use and other potential sources of metal exposures; and (3) to measure metals in blood, urine, saliva, and exhaled breath condensate of e-cigarette users, non-users, smokers and dual users, to evaluate how different patterns of e-cigarette and smoking use impact metal exposure. Researchers will assign 250 adults ages 18 and older to one of five groups: (1) 50 MOD e-cigarette users, (2) 50 POD users, (3) 50 cigarette smokers, (4) 50 dual users of e-cigarettes and combustible tobacco products, and (5) 50 non-users/non-smokers. All participants will answer a questionnaire on smoking history, e-cigarette use patterns, and work/hobbies that may involve metal use. Researchers will collect samples of blood, urine, saliva, and exhaled breath to measure and compare metal levels; samples of e-liquid and vapor will also be collected from e-cigarette users. Researchers will then use linear regression models to estimate the association of metals in biomarkers with e-cigarette use patterns, cotinine biomarkers, and metal concentrations in e-liquid and aerosol. Findings will provide new information about e-cigarette user exposure to metals and may inform regulatory activities related to e-cigarettes.


Johns Hopkins University


National Institute of Environmental Health Sciences/NIH/DHHS


nickel (ni) pod metals aerosols e-cigarettes e-liquid chromium (cr)