Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:1:p5
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 1 (pt 5/16)
Character Range: 2063088–2066182

by FSANZ in 2011 (FSANZ 2011). Based on data presented in this report, dietary intake of arsenic for children aged 25 years ranges from a mean of 1.2 µg/kg/day to a 90th percentile of 2.8 µg/kg/day. These intakes are based on total arsenic in produce, rather than inorganic arsenic.

Review of background intakes from food, water, air, soil and contact with play equipment, based on available Australian data presented by APVMA (2005), suggests background intakes of inorganic arsenic by young children may average 0.62 µg/kg/day. Further review of inorganic arsenic intakes by the Joint FAO/WHO Expert Committee on Food Additives (WHO 2011a) indicated that for populations not located in areas of arsenic-contaminated groundwater, intakes by young children ranged from 0.141.39 µg/kg/day. On the basis of the range of intake estimations available, a reasonable estimation of 50% of the oral toxicity reference value (TRV) from sources other than soil has been assumed. 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 (addressed when assessing intakes from home-grown produce).

Intakes from inhalation exposures are low (around 0.0017 µg/kg/day (APVMA 2005)), comprising <1% of the inhalation TRV adopted.

1.4              Identification of Toxicity Reference Values
With respect to arsenic toxicity and the identification of appropriate toxicity reference values, a number of issues need to be considered. These include:
    * the relevance of non-threshold carcinogenic values for the assessment of oral exposures
    * identification of an appropriate oral toxicity value
    * identification of an appropriate approach and value for inhalation exposures.
These are discussed below.

    1.4.1         Classification
The International Agency for Research on Cancer (IARC) has classified arsenic and inorganic arsenic compounds as Group 1   'carcinogenic to humans' (IARC 2012).

    1.4.2         Review of Oral Information
Arsenic is a known human carcinogen, based on human epidemiological studies that show skin and internal cancers (in particular, bladder, liver and lung) associated with chronic exposures to arsenic in drinking water. The research available on arsenic carcinogenicity is dominated by epidemiological studies (which have limitations) rather than animal studies. This differs from carcinogenic assessments undertaken on many other chemicals. The principal reason for the lack of animal studies is because arsenic has not been shown to cause cancer in rodents (the most common species used in animal tests), due to interspecies differences between rodents and humans.

Review of arsenic by IARC (2012) has concluded the following:
    * For inorganic arsenic and its metabolites, the evidence points to weak or non-existent direct mutagenesis (genotoxicity), which is seen only at highly cytotoxic concentrations.
    * Long-term, low-dose exposures to inorganic arsenic (more relevant to human exposure) is likely to cause increased mutagenesis