Total Ionizing Dose experiment

The challenge in determining the dermal absorption values most relevant to factor into a risk assessment process for environmental contaminants is to define the most relevant parameter (i.e., flux, permeability coefficient, percentage absorption, or total systemic load). For example, when using in vitro techniques to determine potential dermal absorption of a contaminant in water (in which it will probably be present at low concentrations), the most common model would use an infinite dose aqueous application. This will allow the determination of flux and the calculation of a permeability coefficient. However, from such an experiment, the percentage absorption value will be practically meaningless. The total systemic load will be dependent on many other factors, such as concentration and solubility of contaminant within the medium, pH of the medium (and thus the degree of ionization of the contaminant). 

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