Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:4:p14
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 4 (pt 14/24)
Character Range: 979214–982296

is likely to represent the main potential transfer of soil contamination to adults and children. An assessment of exposure from this pathway depends on three critical factors: how much contamination is likely to be accumulated by garden vegetables from the surrounding soil, how much home-grown produce is likely to be consumed by those in the household, and how much contamination in food is absorbed by the human body (Paustenbach 2000).

Limited published information is available on the percentage of Australian households having domestic fruit and vegetable gardens, and on the percentage of home-grown fruit and vegetables consumed in comparison to those purchased. However, health risk assessments are site-specific and therefore this information may be obtained through discussion with the site owner/occupier at the CSM development stage. In the absence of site-specific information, Cross and Taylor (1996) provide a summary of information currently available.

Contaminant uptake behaviour varies markedly between plant species and for different contaminants. Ideally, the concentration of contaminants in home-grown vegetables and fruits should be measured directly on a site-specific basis, but this is often impractical in contaminated land assessments. In the absence of site-specific contaminant uptake data, the chemical concentrations in the edible portions of fruits and vegetables can be predicted from the soil-to-plant concentration factors (CFs), which describe the relationships between the concentrations of contaminants in the soil and plant contaminant concentrations, on a fresh weight basis.

A methodology to estimate contaminant intake from fruit and vegetables for home-grown vegetable intakes of up to 10% of the diet is provided in Schedule B7.

It is recommended that caution be employed in the evaluation of potential human health risks associated with ingestion of fruits and vegetables using generic predictions of plant uptake. Data is limited, and the methods for predicting plant uptake of contaminants from soil and groundwater data are not well validated, particularly for many organic substances. Further site-specific investigations are likely to be justified in situations where the consumption of home-grown produce is likely to constitute a significant portion (>10%) of the diet of a household or where commercial production of vegetables and/or fruit may occur.

    4.6.2          Poultry, meat and fish consumption
The calculation of intake concentrations from the consumption of poultry, meat and fish is complicated and suffers from a number of uncertainties that limit the reliability of the assessment. In order to estimate contaminant concentrations in the potential food source using soil, groundwater and surface water concentrations, the following information is required as a minimum:
    * an understanding of the diet of the exposed population
    * an estimation of contaminant concentrations in the food source consumed by the livestock or fish
    * an estimation of the relative percentage of time spent roaming and