A model for estimation of human exposure to endogenous N-nitrosodimethylamine.

A simple mathematical model is formulated to estimate the order of magnitude of the flux of N-nitrosodimethylamine, based upon blood concentrations and the assumption of a quasi steady state between formation and metabolism. The model predicts a total daily exposure which corresponds to an extrapolated risk well within the observed risk for liver cancer in the USA. The ramifications of this model are significant for cancer prevention and for the development of techniques of risk extrapolation.