Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:11:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 11 (pt 3/9)
Character Range: 2272267–2275138

RfD. Little supporting information is available on the basis for the GAF recommended by US EPA. The recommended oral TRV is derived from WHO (2008) as used in the derivation of the guidelines for drinking water. The TRV is based on drinking water studies in (fasted) nickel-sensitised humans, consistent with the TRV derived from a two-generation drinking water rat study. As the study basis for the GAF differs from that relevant to the TRV adopted, and insufficient data is available on the GAF to determine its relevance to the oral TRV recommended, the application of the GAF has not been considered in the derivation of the soil HIL.

    11.3.3     Inhalation of Dust
Nickel is not volatile and inhalation exposures associated with particulates outdoors and indoors are expected to be of less significance than ingestion of soil. While likely to be negligible, potential inhalation exposures associated with dust have been considered in the HIL derived.

    11.3.4     Plant Uptake
A detailed review of the plant uptake of nickel is presented in EA (2009b). This review considered studies that are based on the uptake of nickel into green vegetables, root vegetables, tuber vegetables, herbaceous fruit, shrub fruit and tree fruit. The review provides recommendations on soil-to-plant uptake factors that are relevant for these types of produce. The recommendations from this review have been considered in the derivation of a residential HIL A and are summarised below for the range of crops considered:
Produce Group     Plant Uptake Factors (mg/kg produce fresh weight per mg/kg soil) (EA, 2009b)
Green vegetables  0.0038
Root vegetables   0.0043
Tuber vegetables  0.0019
Tree fruit        0.0034

It is noted that the inclusion of home-grown produce in the calculations presented for HIL A results in some double counting of intakes from fruit and vegetable produce (also included in background intakes). To address this in the derivation of HIL A, half the intake estimated to be derived from home-grown produce is assumed to be already accounted for in the total background intake (noted below).

    11.3.5     Intakes from Other Sources – Background
Review of current information from Australia indicates the following:
    * Dietary intakes of nickel have been assessed in the 22nd Australian Total Diet Survey (FSANZ 2008), where mean intakes for children aged 23 years were reported to be 8391 µg/day, or 6.26.9 µg/kg/day.  Estimates provided by ATSDR (2005) and EA (2009b) suggest that adult intakes from food are 69162 µg/day (up to 2.3 µg/kg/day) and 130 µg/day (1.9 µg/kg/day) respectively. Intakes for children (ATSDR 2005) range from 6.9 µg/kg/day (611 months old) to 9.5 µg/kg/day (children aged less than 18).
    * Typical concentrations of nickel reported in the ADWG (NHMRC 2011) are less than 0.01 mg/L, resulting in an intake (1 L/day