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

Part C, Section 4
For industrial land use:
• Off-site Migration of Soil/Dust (Section 5.3.5).
The use of these models is described in the sections noted.
The choice of sensitive receptors is linked to land use considerations. Guidelines will be developed for
four defined primary land uses -- agricultural, residential/parkland, commercial, and industrial. While the
details of the nature and extent of exposure arising from these four defined land uses are different, the
practical expression of these differences is dependant on the sensitive human receptor chosen to
represent the occupant or user for the land use, and the exposure period (i.e., the frequency, duration,
and intensity of the exposure assumed for the land use).
Studies indicate that children ingest much greater amounts of soil and dust each day than adults,
primarily due to normal mouthing activity and a greater time spent playing out of doors and on the floor.
This greater intake of soil combined with a lower average body mass to "distribute" the dose places a
child more at risk from contaminated soils than the adult. Similarly, a child's dermal exposure may be
greater, because their skin is less of a physical barrier than an adult's. For dermal exposures, behavioral
considerations are also likely to involve greater proportions of a child's versus an adult's skin (the child is
more likely to expose the lower legs in addition to the face, neck, hands, and arms). Typical values for
these and other receptor characteristics are in Table 2.
Table 2
Typical Average Values for the Canadian Population
Age Classes
(years)
Body
Weight
(kg)
Air intake
(m 3 /day)
Water intake
(L/day)
Soil intake
(mg/day)
Skin surface
areas 1,2
(m 2 )
0-6 mo 7 2 0.75 20 0.30
7 mo-4 yrs 13 5 0.8 80 0.26
5-11 yrs 27 12 0.9 20 0.41
12-19 yrs 57 21 1.3 20 0.43
20+ yrs 70 23 1.5 20 0.43
1. Skin surface areas for different age classes based on: 0-0.5: total body; 0.6-4 and 5-11: head, arms, hands, lower
legs; 12-19 and 20+:head, arms, hands.
2. The amount of dirt assumed to be covering skin surfaces for all age classes is 1.0 mg/cm 2 ; taken from EPA (1990),
Interim Guidance for Dermal Exposure Assessment
Sources: (Health and Welfare Canada, 1989; Angus Environmental, 1991; MENVIQ, 1992)
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