Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:1:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 1 (pt 3/7)
Character Range: 2460596–2463371

the geometric mean of these values yields an average dermal absorption factor of 0.018 (1.8%).'

As few other reviews are available in relation to dermal absorption of DDT, the average value estimated by Wester et al. (1990) as referenced by MfE (2011), has been adopted in the derivation of HILs.

1.3.3         Inhalation of Dust
DDT, DDE and DDD are not considered sufficiently volatile to be of significance and inhalation exposures associated with particulates outdoors and indoors are expected to be of less significance than ingestion of soil. While likely to be negligible, potential inhalation exposures associated with dust have been considered in the HIL derived.

1.3.4         Plant Uptake
As DDT has the potential to bioaccumulate, uptake into fruit and vegetable crops (as well as eggs and poultry where relevant) are likely to be of significance (Beard, 1993). Review by MfE (2011) noted that there are limited studies available for the assessment of plant uptake of DDT, however plant uptake has been considered. It is noted that the few studies available relate to the uptake of DDT in plants when applied in solution (as would be the case as an applied pesticide). DDT, DDE and DDD have a high Koc values (log Koc = 5.195.35, ATSDR 2002) suggesting that these compounds are strongly bound to the soil particulates and immobile in soil (with low solubility in water). For plant uptake to be significant, the chemicals must be able to partition to soil water. In addition there is evidence that DDT, as well as other chemicals, undergoes an ageing process in soil whereby the DDT is sequestered in the soil so decreasing its bioavailability to microorganisms, extractability with solvents, and toxicity to some organisms (ATSDR 2002).

ATSDR (2002) reviewed available studies associated with potential uptake of DDT that is sorbed to soil. The studies show that the potential for uptake was low and there was little or no evidence of translocation. Some uptake was noted where the DDT source was fresh and some volatilisation had occurred resulting in uptake, though this process is not consider relevant for most DDT-contaminated sites as these compounds are no longer used in Australia.

On the basis of the above, the potential for plant uptake of DDT, DDE and/or DDD bound to the soil is considered to be negligible.

It is noted, however, that should these compounds be present in other media such as groundwater (used for irrigation) or in solution then the potential for uptake into fruit and vegetable crops is likely to be of significance. These issues should be assessed on a site-specific basis

1.3.5         Intakes from Other Sources – Background
For the general population, background intakes would be expected to be primarily associated with