user's guide and background technical document for the nevada ...

BW = Body weight of child (15 kg)
AT = Averaging time for child (6 years)
RfDo = Oral reference dose (mg/kg-day)
EF = Exposure frequency (350 days/year)
ED = Exposure duration of child (6 years)
IRS = Soil ingestion rate for child (200 mg/day)
Inhalation of Carcinogenic Contaminants
Eq. 3
where:
mg/kg =
TR AT
EF ED ET CF [( 1 1
) or (
PEF VF )]
TR = Target risk of 10 -6
AT = Averaging time (70 years x 365 days/year x 24 hours/day)
IURi = Inhalation unit risk (chemical-specific) (μg/m 3 ) -1
EF = Exposure frequency (350 days/year)
ED = Exposure duration (30 years)
ET = Exposure time (24 hours/day)
CF = Conversion factor (1,000 μg/mg)
PEF = Particulate emission factor used for dusts (1.2×10 9 m 3 /kg)
VF = Volatilization factor used for volatile organic chemicals (m 3 /kg)
Inhalation of Non-carcinogenic Contaminants
Eq. 4
where:
mg/kg =
THQ AT
EF ED ET 1
[( 1 1
) or (
PEF VF )]
THQ = Target hazard quotient of 1
AT = Averaging time for child (6 years x 365 days/year x 24 hours/day)
EF = Exposure frequency (350 days/year)
ED = Exposure duration for child (6 years)
ET = Exposure time (24 hours/day)
RfCi = Inhalation reference concentration in (chemical specific) (mg/m 3 )
PEF = Particulate emission factor used for dusts (1.2×10 9 m 3 /kg)
VF = Volatilization factor used for volatile organic chemicals (m 3 /kg)
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