Tritium Dose Conversion Factor Confusion

[/I=J/S=PRESLEY/O=AECB.CCEA@mhs-atomcon.attmail.com]

     Fellow Radsafers
     
     
     I am pondering the numbers used for Dose Conversion Factors for
     airborne exposure to Tritiated Water.
     
     ICRP-30 Part 1 pg 65 states that it includes allowance for
     the absorption through skin.
     Using the numbers quoted there I "backcalculate" a DCF
     of about 6.2 E-5  rem/uCi
     
     However, in ICRP 68 pg 75
     The corresponding number for tritiated water is
     1.8E-11 Sv/Bq  or about 6.6 E-5 rem/uCi.
     But this table states that skin absorption is NOT accounted for.
     
     Can anyone clear this up for me ?
     I would expect the ICRP 68 value to be about 40%
     smaller if skin absorption has not been included.
     
     James Presley
     
     ATOMCON/I=J/S=PRESLEY/O=AECB.CCEA@MHS.ATTMAIL.COM