Metals from e-cigarette aerosols accumulate in the brain
Mice exposed to e-cigarette aerosols had a buildup of toxic metals in the brain, according to NIEHS-funded researchers. The exposure also altered brain levels of essential metals, which play a key role in many biological processes. The findings provide clues about the onset of neurodegenerative diseases, which have been linked to toxic metal exposure and the dysregulation of essential metals.
The researchers exposed mice to either the equivalent of secondhand e-cigarette aerosol or a five-fold higher level for two months. They then measured levels of 15 different metals in brain and other central nervous system (CNS) tissues, such as the spinal cord.
Compared with unexposed mice, mice exposed to e-cigarette aerosol had significant buildup of several metals in the brain and CNS. Many of the metals that accumulated in exposed mice were known neurotoxins, including chromium, copper, iron, and lead. The number of metals and their concentrations in the brain were more pronounced in the high-dose group. The most striking changes in brain metal levels were in the striatum, which controls movement, action selection, and reward learning. Exposed mice also had reduced levels of some essential metals, such as selenium and zinc.
According to the authors, exposure to e-cigarette aerosol can increase deposition of neurotoxic metals in the brain and alter essential metal levels, potentially increasing the risk of neurodegenerative disease for both e-cigarette users and bystanders.
Citation: Re DB, Hilpert M, Saglimbeni B, Strait M, Ilievski V, Coady M, Talayero M, Wilmsen K, Chesnais H, Balac O, Glabonjat RA, Slavkovich V, Yan B, Graziano J, Navas-Acien A, Kleiman NJ. 2021. Exposure to e-cigarette aerosol over two months induces accumulation of neurotoxic metals and alteration of essential metals in mouse brain. Environ Res 202:111557.