Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:5:p6
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 5 (pt 6/18)
Character Range: 2986446–2989293

situations where soil pica behaviour is likely to occur.

5.3.1.2         Ingestion of soil adhering to home-grown produce
The approach applied to estimate the ingestion rate of soil adhering to home-grown produce was derived from the methodology outlined by the UK Environment Agency (EA 2009e). This approach involves the application of a soil loading factor to account for the adherence of soil to home-grown produce, and a preparation factor to account for the influence of food preparation practices (for example, washing and peeling) on soil loading. The quantity of soil ingested also depends on the amount of home-grown produce consumed. Applying the current UK values to the produce consumption rates assumed relevant for Australia results is the equivalent of an additional soil ingestion rate of approximately 3 mg/day for an adult and 2 mg/day for a child, if 10% of produce is grown at home. This intake is considered only minor in comparison with the soil/dust ingestion rates adopted for adults (50 mg/day) and children (100 mg/day) in HIL A, and is considered to be adequately encompassed within the level of uncertainty inherent in the ingestion rates adopted. Hence, the additional contribution of soil ingested from home-grown produce has not been considered separately in the derivation of HIL A.

Note that the contribution of soil ingested from home-grown produce may be of significance in a site-specific risk assessment where higher intakes of home-grown produce or more site-specific soil/dust ingestion rates are considered.

    5.3.2         Dermal contact with surface soil and dust particulates
This exposure pathway considers the dermal uptake of chemicals following skin contact with contaminated soil and dust. Dermal exposure to contaminants is dependent on the following parameters:
    * the area of exposed skin and the degree of contact with soil or dust
    * the amount of soil adhering to the skin
    * the amount of contaminant absorbed through the skin.
The exposure parameters specific to the dermal contact pathway are discussed in detail below.

5.3.2.1         Area of exposed skin
Clothing reduces dermal contact with contaminated soil. Therefore, the area of exposed skin applied in the derivation of the HILs has been based on the percentage of the skin surface area that is not covered by clothes, on average, under normal Australian circumstances.

enHealth (2012a) provides an estimate of 6100 cm2 for the total skin surface area of a 23-year-old child. An average of 44.3% of this area is estimated to be exposed, based on analysis of the percentage skin surface area not covered during warm weather (that is, the child is wearing shorts or skirt, a short-sleeved shirt and no socks or shoes).

The total skin surface area recommended by enHealth (2012a) for adult exposure is
20 000 cm2. In