5.1 CHEMICAL DATABASE SUMMARY
    Pollutant-specific parameters are provided to the MEPAS software package through a chemical database described in detail by Strenge and Peterson (1989). A summary of the parameters given in the database is presented in Table 5.1 to establish the relationship with the parameters described in Sections 2.0 and 3.0.

TABLE 5.1 Parameters Contained in the Chemical Database for Each Pollutant

Symbol
  
Units
  
Default Value
  
Parameter Description
 
MWi   g/mole   None   Molecular weight 
VPi   mm Hg   None   Vapor pressure
Hi   atm m3/mole   None   Henry's Law Constant
Si   mg/L   None   Water solubility
Kowi   ml/g   None   Octanol-water partition coefficient
Koci   ml/g   None   Carbon matter partition coefficient
Kpi   cm/h   0.001   Skin permeability constant for aqueous solutions
HTai   d   3.7E9   Half-time for the constituent in air
HTgw   d   3.7E9   Half-time for the constituent in ground- water or confined water systems
HTsw   d   3.7E9   Half-time for the constituent in surface water
HTsl   d   3.7E9   Half-time for the constituent in soil 
DFgi   rem/pCi   None   Radionuclide ingestion dose factor
DFhi   rem/pCi   None   Radionuclide ingestion dose factor
DFdi   rem/pCi   None   Radionuclide dermal absorption dose factor
DEai   rem/h per pCi/m3   None</td>   External radiation dose factor for exposure to activity in air
DEgi   rem/h per pCi/m2   None   External radiation dose factor for exposure to ground activity
DEwi   rem/h per pCi/L   None   External radiation dose factor for exposure by immersion in water
Bif   None   None   Bioaccumulation factor for finfish
Bis   None   None   Bioaccumulation factor for shellfish
Bvi   None   None   Soil-to-edible plant concentration ratio
FMmti   d/kg   None   Feed-to-animal meat transfer factor 
FMmki   d/L    None   Feed-to-cow milk transfer factor
TFi   None   1.0   Water purification factor, fraction remaining after treatment
Vdi   m/sec   None   Deposition velocity
Kai   None   None   Atmospheric deposition class
SFhi   (mg/kg/d)-1   None   Chemical inhalation slope factor 
SFhi   risk per pCi   None   Radionuclide inhalation slope factor 
SFgi   (mg/kg/d)-1   None   Chemical ingestion slope factor 
SFgi   risk per pCi   None   Radionuclides ingestion slope factor 
RfDhi   mg/kg/d   None   Chemical inhalation reference dose 
SFsi   risk/yr per pCi/g   None   Radionuclide external dose slope factor for exposure to surface contamination
RfDgi   mg/kg/d   None   Chemical ingestion reference dose 
f1i   None   1.0   GI tract absorption fraction
ABdi   None   0.001   Skin absorption fraction for soil exposure for inorganic chemicals and radionuclides
        1.0   Skin absorption fraction for soil exposure for organic chemicals