Document JyeLN8gGvv16q7z2kVnjemJe

Qu ~ Tm Mohamed T. Elnabarawy on 07/25/2000 04:42:06 PM ToT:o; Suc SRSHaaenrnvotaAnCCaoPoanmrwacpliaREnACoKEcCeooopmsamoOrpSCSorGaoCsorlmoCeoerltSeoanesin Posies Woh Wit cc: MMiicchhaaeell AA.. SSaannttoorrco/U/USS--CCoorrppoorartaet/3eM/3/MUUSS@@33MM-C-Coroprpoorraattee Sheryl A. CorriganlUS-Corporatel3MIUS@3M-Corporate Mark A. Gaetz/US-Corporate/3M/US@3M-Corporate KKaeiitthh JJ.. MMiillleler/rU/SU-SC-oCorproproartaet/3eM/3/WU/SU@ S@33MM--CCoorrppoorraattee Robert A. Paschke/US-Corporate/3M/US@3M-Corporate Screening-Level Risk Assessment for Organofluorine Substances in Philippines Well Water Ark nd hat est reson xponurs assent wes pred n cole At Mark and Sheryl's request, residential exposure assessment was performed on two organofl~ CSubIstRanc)es i FOS andaPFOAo. ThweasslwohseubFsnens. so8n,g iPhFE1caresopecshomlooued PHS) substances: PFOS, and PFOA. These two substances, along with their respective homologues~ PFHSJ~ and PFHA ) co-occur in monitoring wells at the Philippines site. PFBS is also detected in these w.#If~'~--~ Exons Scan: Resdrt adn Exposure Scenario : Residential adult. Sano away Dik vor Exposure Pathway : Drinking water. Expoure Roa: ingen o moa Exposure Route : Ingestion of well water. Recommancad rpm Flossing kr Resid Narciso Expose Recommended Exposure Factors/Assumptions for Residential Noncarcinogen Exposure: tare (ROC a --BIontdaykeweriagteht( - Body weight IR ) = 2L/day. (( BBWW)) ==7700kkgg.. ranges (AT) 35s x85 dy yor. - Averaging time ( AT ) =30 years x 365 day/year. "Eons aun (6) 50 cy er, - Exposure frequency (EF) =350 day/year. "Eon rtion{ Coy youn - Exposure duration (ED) = 30 years. Gave Expostn Dose Calculated Exposure Dose: To gone Gos Coan chon ly naka a3 8 1 chricalRboy wih The exposure dose is a calculation of chronic daily intake expressed as mg chemical/kg body weight/day,~ Tho cacao spam van ow org ogni The calculation is performed using the following equation : Eovoars Somirorom = E5C) (ROW (6 OAT Exposure Dose(mg/kg/d) = (EPC). (IR,tBW). ( EF. ED/AT) ir W EEPPhCCereiiss: eexxppoossuurree ppooiinntt ccoonncceennttrraattiioonn iinn mmgglL/L.. is na rt ny IR is intake rate = 2L/day. BW boy wa +700 BW is body weight =70kg. BED as io exper por. EF, ED and AT define exposure period. [rr Estimated Risks: Noretonage of Hazed ucint so tno ook sctd wh could xpos Noncarcinogen risk or Hazard Quotient is an estimation of risk associated with the calculated exposure Cov aan Guan a of had oom Gos over sec a pone Gos dose. Hazard Quotient is the ratio of calculated exposure dose over the acceptable daily exposure dose, Cerinspecie scope doy pos eso expound vs Rlorrcs Doss o Chemical-specific acceptable daily exposure or "threshold exposure" is termed the Reference Dose or Ra esd 1 aA hoy won) RfD, and is expressed in mg chemical/Kg body weight/day. 0.2 Cacsad Exposure ose RD HQ = Calculated Exposure Dose/RfD jo Where: HG Hora uote HQ is Hazard Quotient, rl RD va 705 00001 mpgs OOOrrraaalll RRRIffDDD vvvaaallluuueee for ffoorr PFOS PPFFOOAA = == 0.00015 mg/Kg/d 00..00000033 mmgg//kKgg//dd Th loin tai shows te gancarcogen kms or nesionofwolvelar in PROS and The following table shows the noncarcinogen risk estimates for ingestion of well water with PFOS and EEO acai ha eplod pte ste ot rs BTR 10 ae 1 ve or 691 PFOA occurring .The reported duplicate analytical values were averaged to derive a single value for each Jukietonit monitoring well. 11773311..00000011 Exhibit 1731 pry 3M MN01020427