Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:8:p4
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 8 (pt 4/8)
Character Range: 2207623–2210521

from the diet. In areas where the form of lead in soil is more soluble and available for plant uptake a site-specific assessment (including the sampling of home-grown produce) should be considered.

    8.3.5         Intakes from Other Sources – Background
Information available from Australia in relation to background intakes of lead include the following:
    * Dietary intakes of lead have been reported from FSANZ (2003 and 2011). Intakes reported in this study range from 0.020.4 µg/kg/day for adults to 0.011.2 µg/kg/day for infants. This data is the most current from FSANZ and is noted to comprise up to 33.3% of the adopted TDI (the same as is recommended for oral TRV). The average of the range presented has been considered in calculations presented using the IEUBK model.
    * The ADWG (NHMRC 2011) notes that lead concentrations in drinking water range up to 0.01 mg/L with typical concentrations less than 0.005 mg/L. Data available from South Australia (based on 5 years of data) suggest concentrations of lead in drinking water are on average 0.0007 mg/L, with a maximum of 0.014 mg/L. Intakes derived for a young child (consuming 1 L/day and a body weight of 15.5 kg) is approximately 0.04 µg/kg/day.
    * Concentrations of lead in air have been derived from Australian data on lead levels in urban, suburban and rural areas. NSW (DEC 2003) report concentrations of lead in air that range from 2.499 ng/m3 with an average of 30 ng/m3. Intakes derived from urban air are considered negligible in comparison with those derived from dietary and water sources.
    * Total intakes from sources other than soil are estimated to be up to 1.2 µg/kg/day. This is comparable with background intakes estimated by MfE (2011) of 0.97 µg/kg/day.

8.4              Identification of Toxicity Reference Values

    8.4.1         Classification
The International Agency for Research on Cancer (IARC 2006) has classified inorganic lead as Group 2A—probably carcinogenic to humans. Organolead was classified as Group 3—not classifiable.

It is noted that US EPA (available from IRIS 2012) has classified lead and compounds (last reviewed in 1993) as Class B2—probable human carcinogen.

    8.4.2         Review of Available Values/Information
Some evidence of carcinogenic effects has been associated with exposure to lead (in experimental animals, with inadequate evidence in humans). It is noted ,however, that there is evidence from human studies that adverse effects other than cancer may occur at lower lead levels (WHO 2011), hence the adoption of a guideline that addresses the most sensitive non-carcinogenic effects is considered to also be adequately protective of carcinogenic effects.

Blood lead levels have been found to be a good indicator of exposure to lead. A blood lead level reflects lead's dynamic equilibrium between adsorption, excretion and deposition in soft and hard