Exposure to metals among Electronic Nicotine Delivery System (ENDS) users in the PaTh study: a longitudinal analysis.

Introduction:
This text provides an analysis of the Population assessment of Tobacco and health (PaTh) Study regarding the association between Electronic Nicotine Delivery Systems (ENDS) use and metal exposure in urine samples. The study compares urinary metal concentrations among ENDS only users who never used any tobacco products, ENDS only users who were former users of any tobacco products, and never users of any tobacco products. The analysis focuses on seven metals and adjusts for various covariates, including age, sex, race/ethnicity, education, region, secondhand smoke exposure, and substance use.

Key Points:

* The study uses data from the PaTh Study wave 1 (2013-2014), wave 2 (2014-2015), and wave 3 (2015-2016).
* The analysis includes 1674 adult participants, with 1501 never users of any tobacco product, 50 ENDS users who never used any tobacco product, and 123 ENDS users who were former users of any tobacco product.
* The study measures urinary concentrations of seven metals: beryllium (Be), cadmium (Cd), cobalt (Co), manganese (Mn), lead (Pb), strontium (Sr), thallium (Tl), and uranium (U).
* after adjusting for covariates, the study finds that ENDS users who never used any tobacco product have significantly higher urinary concentrations of Cd and Pb compared to never users of any tobacco product (GMRs of 1.25 and 1.19, respectively).
* Similarly, ENDS users who were former users of any tobacco product have significantly higher urinary concentrations of Cd and Pb compared to never users of any tobacco product (GMRs of 1.48 and 1.43, respectively).
* The study did not find significant differences in urinary concentrations of Be, Co, Mn, Sr, Tl, or U between ENDS users and never users of any tobacco product.
* The study also did not find significant differences in urinary concentrations of Cd and Pb between ENDS users who never used any tobacco product and ENDS users who were former users of any tobacco product.

Main Message:
The study provides evidence that ENDS use is associated with higher urinary concentrations of Cd and Pb, regardless of whether the users were former tobacco product users or not. These findings suggest that ENDS use can potentially contribute to the body burden of several metals among long-term users. however, the study notes that the results are limited by the small number of participants who used ENDS exclusively and the possibility of underreporting of past combustible products. Further research is needed to clarify the potential long-term harmful health effects of ENDS associated with metals and other chemicals to inform regulators, consumers, and manufacturers.

Kaplan B, Navas-acien a, Rule aM, hilpert M, Cohen JE. Exposure to metals among Electronic Nicotine Delivery System (ENDS) users in the PaTh study: a longitudinal analysis. Environmental research. 2023;231:116032. doi:10.1016/j.envres.2023.116032