Depending on land use and corresponding human activities, a number of exposure pathways are relevant for human exposure. In this chapter, six important pathways are described, i.e., exposure through consumption of vegetables, consumption of animal products, consumption of domestic water, inhalation of vapours outdoors, inhalation of dust particles (indoors and outdoors) and dermal uptake via soil material (outdoors and indoors). Note that these exposure pathways follow different exposure routes to enter the human body, i.e., oral, inhalation and dermal routes, respectively. Human exposure through all oral and inhalative exposure pathways described in this chapter (so excluding the dermal uptake exposure pathway), follow a similar pattern. This pattern includes three steps. Firstly, the transfer of contaminants from one of the mobile phases of the soil (pore water or soil gas) into a so-called contact medium. Secondly, the intake of that contact medium by human beings. And thirdly, the uptake of part of the contaminants from the contact medium into the blood stream and target organs and the corresponding excretion of the remaining part of the contaminants. For each of the pathways the significance, conceptual model, an example of mathematical equations and of the input parameters is described in this chapter, in detail. Moreover, attention is given to the reliability and limitations of the calculations.
