Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:9:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 9 (pt 3/7)
Character Range: 2224647–2227507

soil are sufficiently high to address deficiencies but where plant deficiencies occur it is typically due to manganese being present in a form not available for plant uptake. Hence the potential for plant uptake and toxicity will be dependent on the form present. While a comprehensive review of plant uptake has not been conducted in this review, the potential for manganese uptake into plants has been considered in the derivation of HIL A.

Based on the above, the uptake of manganese into all crops has been considered in the derivation of the HIL A. Limited plant uptake data is available, and translocation into above-ground crops is assumed to be negligible, hence the value presented by RAIS (2010) of 0.068 mg/kg fresh produce per mg/kg soil produce has been considered for root and tuber crops only.

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).

    9.3.5         Intakes from Other Sources – Background
Review of current information from Australia indicates the following:
    * Review of manganese by FSANZ (2011) indicates that for young children aged 23 years, intakes range from a mean of 0.19 mg/kg/day to a 90th percentile of 0.26 mg/kg/day. These intakes are higher than estimated in the previous HIL evaluation and by ATSDR. Dietary intakes of manganese reported by WHO are summarised by Lindon & Sabordo (1996) and are approximately 0.06 mg/kg/day for young children. Estimates provided by ATSDR (2008) suggest that adult intakes of food are 3.8 mg/day (or 0.05 mg/kg/day).
    * Typical concentrations of manganese reported in the ADWG (NHMRC 2011) are less than 0.01 mg/L, resulting in an intake (1 L/day and body weight of 15.5 kg) by toddlers of 0.00076 mg/kg/day.
    * Based on the above background intakes for young children, it has been assumed that background oral intakes comprise 50% of the recommended oral TRV.
    * Manganese was reported in ambient air data collected in NSW (DEC 2003) where concentrations (24-hour averages) in urban, regional and industrial areas assessed ranged from 3.7119 ng/m3 (average of 18 ng/m3). Typical concentrations in air have been reported by ATSDR (2008) to be 23 ng/m3, consistent with that reported by DEC (2003). These background concentrations comprise (based on average concentrations) approximately 15% of the recommended inhalation TRV. A conservative background of 20% of the inhalation TRV could be assumed for intakes from air.

9.4              Identification of Toxicity Reference Values

    9.4.1         Classification