Data and resource requirements

Human exposure assessments require data and models to address a number of key relationships. Here we consider the requirements for data for establishing both the structure and the numerical value of these links. Human exposures to environmental emissions include at least five important relationships that will demand data, modelling and evaluation resources  

1) the magnitude of the source medium concentration—that is, the level of contaminant that is released to indoor or outdoor air, soil, water, etc. or the level of contamination measured in or estimated in the air, soil, plants and water in the vicinity of the source  

2) the contaminant concentration ratio, which defines how much a source medium concentration changes as a result of transfers, degradation, partitioning, bioconcentration and/or dilution to other environmental media before human contact  

3) the level of human contact, which describes (often on a body weight basis) the frequency (days per year, minutes per day, etc.) and magnitude (cubic metres of air breathed per hour, kilograms of food ingested per day, square metres of surface contacted per hour, etc.) of human contact with a potentially contaminated exposure medium  

4) the duration of potential contact for the population of interest relating to the fraction of lifetime during which an individual is potentially exposed and 

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