DNA adducts form in mouse lung and liver after oral naphthalene exposure

Naphthalene is a ubiquitous environmental contaminant and suspected
carcinogen that forms DNA adducts in tissue explants, which is a mechanism
of concern for genotoxicity, but it was not known if naphthalene could
form DNA adducts in vivo. Naphthalene-DNA adducts are small and difficult
to detect, so we utilized accelerator mass spectrometry to detect adducts
with high sensitivity.  Wild-type C57BL/6 mice were orally
exposed to 50 mg/kg 14C-naphthalene, lung and liver were collected 2, 4,
24, or 72 hours post-exposure, then DNA was isolated from the tissue. DNA
was then processed for accelerator mass spectrometry analysis following
standard protocols, explained in detail in Domanico et al.
(2025)(doi.org/10.1093/toxsci/kfaf017). Resulting measurements of 14C
signal in these DNA samples comprise this dataset, and can be used to
calculate the level of DNA adduct formation in tissue. We detected
naphthalene-DNA adducts at various timepoints post-exposure, with levels
decreasing over time, though a subset of DNA adducts still persisted to 72
hours post-exposure in both lung and liver. Evidence of naphthalene-DNA
adduct formation in vivo provides a foundation for further studies into
the potential genotoxic mechanism of naphthalene.