Protocol for the Derivation of Environmental and Human ... - CCME

Part B, Section 5
5.2.2 Maintenance of Resident and Transitory Wildlife
To ensure that residential/parkland land use can sustain resident wildlife populations and transitory
wildlife, an exposure scenario must consider the primary routes of exposure to wildlife on these lands.
Dermal contact and contaminated soil and food ingestion by wildlife pose a significant health concern to
these organisms. Information on the effects from these exposures to wildlife (other than some grazing
herbivores) is severely lacking (OECD, 1988). Because of these data limitations, it is assumed that the
level of protection offered to soil-dependent organisms from direct contact exposures is adequate to
protect wildlife from dermal and ingestion exposures. This assumption is based on the notion that soildependent
organisms are more directly in contact with the medium for a large portion of their life-cycle
and will therefore be a more sensitive indicator of adverse effects than organisms at higher trophic levels.
This assumption will be held except where explicit information to the contrary exists (e.g.,
Molybdenum, Selenium). However, effects from dermal contact and soil and food ingestion should be
considered for guideline derivation for residential/parkland land use when information becomes
available.
5.3 Commercial Land Use
The nature of commercial land use is variable and can range from lands that approximate residential
conditions (e.g., local gas stations) to lands that border on industrial activities (e.g., warehouse) (see
Figure 3). This makes it difficult to describe key ecological receptors and exposure pathways for
commercial land use. However, using the description of commercial land use in Section 2.4 of Part A,
the degree to which maintenance of ecological functions is required will depend on the degree to which
the site has been developed. From an ecological standpoint, the SEQCCS envisions a generic
commercial land to include managed (e.g., cultivated lawns, flowerbeds) as opposed to natural
ecological areas (e.g., forests). The ecological receptors predicted to be present on commercial lands
are similar to those identified for residential/parkland lands (i.e., soil-dependent biota, wildlife) since
these receptors sustain the managed ecological areas of commercial lands. However, on commercial
lands, it is assumed that the normal land use activities do not depend on the maintenance of ecological
functioning to the same degree as on agricultural or residential/parkland lands.
The main route of exposure for soil-dependent biota and wildlife is most likely to be direct contact with
contaminated soil. Due to the lack of information on the effects of direct soil contact on wildlife, the
protection assumption used in the residential/parkland and agricultural land use categories is also used
here. Soil ingestion by wildlife on commercial lands, at a generic level, is not thought to be significant
because residence time on commercial lands is predicted to be low relative to agricultural and
residential/parkland lands. Therefore guidelines are derived for commercial land use based on the direct
contact of contaminated soil to soil-dependent biota and wildlife. A generic exposure scenario and
receptor array for a commercial site is shown in Figure 7.
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