Vg. Zartarian et al., A modeling framework for estimating children's residential exposure and dose to chlorpyrifos via dermal residue contact and nondietary ingestion, ENVIR H PER, 108(6), 2000, pp. 505-514
To help address the Food Quality Protection Act of 1996;, a physically base
d probabilistic model has been developed to quantify and analyze dermal and
nondietary ingestion exposure and dose to pesticides. The Residential Stoc
hastic Human Exposure and Dose Simulation Model for Pesticides (Residential
-SHEDS) simulates the exposures and doses of children contacting residues o
n surfaces in treated residences and on turf in treated residential yards.
The simulations combine sequential time-location-activity information from
children's diaries with microlevel videotaped activity data, probability di
stributions of measured surface residues and exposure factors, and pharmaco
kinetic rate constants. Model outputs include individual profiles and popul
ation statistics for daily dermal loading, mass in the blood compartment, i
ngested residue via nondietary objects, and mass of eliminated metabolite,
as well as contributions from various routes, pathways, and media. To illus
trate the capabilities of the model framework, we applied Residential-SHEDS
to estimate children's residential exposure and dose to chlorpyrifos for 1
2 exposure scenarios: 2 age groups (0-4 and 5-9 years); 2 indoor pesticide
application methods (broadcast and crack and crevice); and 3 postindoor app
lication time periods (< 1, 1-7, and 8-30 days). Independent residential tu
rf applications (liquid or granular) were included in each of these scenari
os. Despite the current data limitations and model assumptions, the case st
udy predicts exposure and dose estimates that compare well to measurements
in the published literature, and provides insights to the relative importan
ce of exposure scenarios and pathways.