Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:7:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 7 (pt 3/6)
Character Range: 2188338–2191170

toxicity associated with excess levels of copper. The potential for plant uptake and toxicity will be dependent on the form present. Review by MfE (2011) notes that copper is phytotoxic at relatively low tissue concentrations and plant uptake will be limited by its toxic effect on plants. A tissue copper concentration of 1520 mg/kg (dry weight) is considered to be representative of excessive tissue concentration in agronomic species, while a 10% growth yield decrease is most likely at 1030 mg/kg (dry weight) tissue copper concentrations.

Given the variable uptake of copper by plants from soil, and the known phytotoxic effects of copper, it is recommended that a maximal concentration of copper in produce is used in preference to a plant uptake factor (which is not limiting). A produce concentration of 30 mg/kg (dry weight) has been considered by MfE (2011) as the maximum amount of copper likely to be taken up in home-grown vegetables. Vegetables containing greater than this concentration would be so stunted and deformed that harvesting would be unlikely.

To obtain the additional background intake, a child's produce consumption (0.048 kg DW[2]/day) was multiplied by 30 mg/kg and divided by the child body weight of 15.5 kg to obtain the maximum additional background daily intake for 100 % of produce being home-grown. For the consumption of 10% home-grown produce, this results in an additional intake of 0.009 mg/kg/day being considered.

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). Given the low tissue concentration required for phytotoxicity it is expected that existing background intakes already address maximum amounts of copper uptake, however, to be conservative the additional uptake calculated here has been assumed to be in addition to the background intakes (noted below).

    7.3.5         Intakes from Other Sources – Background
Review of current information from Australia with respect to copper indicates the following:
    * Intakes of copper were reported in the 20th Total Diet Survey (FSANZ 2003) where intakes by infants were identified as highest, at 0.065 mg/kg/day. Intakes by toddlers (2 years) were up to 0.04 mg/kg/day. Intakes of copper in the 23rd Australian Total Diet Study (FSANZ 2011) indicated intakes by young children aged 23 years ranged from a mean of 0.068 mg/kg/day to a 90th percentile of 0.094 mg/kg/day.
    * Typical concentrations of copper reported in the ADWG (NHMRC 2011) are 0.05 mg/L, resulting in an intake (1 L/day and body weight of 15.5 kg) by toddlers of 0.004 mg/kg/day. It is noted that intakes of copper in drinking water supplies in New Zealand (MfE 2011) were higher, with intakes by