Description Publication 100 provides a Human Alimentary Tract Model (HATM) to complement the Publication 66 Human Respiratory Tract Model (HRTM),
published in 1994. Both models replaced Publication 30 (1979) models, which were developed specifically for the calculation of doses
from occupational exposures to radionuclides. An important aspect of both the HATM and HRTM is their treatment of intakes by children
as well as male and female adults and hence their applicability to environmental as well as occupational exposures. Another important
development in both models is the specific calculation of doses to target regions containing cells considered to be susceptible to cancer
induction.