Exposure to naphthalene induces naphthyl-keratin adducts in human epidermis in vitro and in vivo

Abstract

We observed naphthyl-keratin adducts and dose-related metabolic enzyme induction at the mRNA level in reconstructed human epidermis in vitro after exposure to naphthalene. Immunofluorescence detection of 2-naphthyl-keratin-1 adducts confirmed the metabolism of naphthalene and adduction of keratin. We also observed naphthyl-keratin adducts in dermal tape-strip samples collected from naphthalene-exposed workers at levels ranging from 0.004 to 6.104 pmol adduct µg⁻¹ keratin. We have demonstrated the ability of the human skin to metabolize naphthalene and to form naphthyl-keratin adducts both in vitro and in vivo. The results indicate the potential use of keratin adducts as biomarkers of dermal exposure.

Keywords::

• Biomarkers
• dermal exposure
• jet fuel
• keratin adducts
• naphthalene (CAS 91-20-3)

Acknowledgements

The authors thank the workers for their participation in the study.

Declaration of interest

The authors declare they have no competing financial interests. This work was supported by US Air Force (Texas Tech University subcontract 1331/0489-01), National Institute of Environmental Health Sciences (grant number P42ES05948 and the Division of Intramural Research ES021134) and National Institute for Occupational Safety and Health (grant numbers T42/CCT422952, T42/008673). The authors report no conflicts of interest.