Despite the supposition that human exposure assessment (HEA) is important to some toxicologists, documentation of this subject matter in toxicology textbooks is incomplete and fragmented. To this date, most toxicology textbooks have provided only one or two sections on HEA, typically as part of a chapter on health risk assessment (RA).

Many toxicologists do not find HEA appealing, in part because they are better trained to use animal models or bioassays as investigation tools. Another reason is that RA, that requiring HEA (see, e.g., Slide 10 of Lecture 2), is still an emerging field. Undoubtedly there are toxicologists measuring exposure levels for pathological examination, for clinical investigation, and for forensic analysis. Yet measurements of these types are primarily on single individuals without the apparent goal of protecting public health.

Many toxicologists nonetheless have been constantly working indirectly with epidemiologists and others involved in HEA. For example, toxicologists have been conducting animal (and even human) studies to determine the dermal absorption of chemicals. These absorption studies have enabled the exposure assessor to estimate the internal dose from dermal exposure to these compounds (using the animal values as surrogate for humans). Environmental toxicologists too have a fair amount of knowledge about the air, water, and soil concentrations of certain environmental contaminants in various parts of a country or the world. As another example, food toxicologists and nutritional epidemiologists are seen to work together closely in assessing dietary intake.