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File: 970107_sep96_decls52_0006.txt
Subject: KUWAIT ASSESSMENT OF POTENTIAL GROUNDWATER CONTAMINATION
Unit: OTSG
Parent Organization: HSC
Box ID: BX003205
Folder Title: EXPOSURE CALCULATIONS
Document Number: 1
Folder Seq #: 19
'r@CEt4@iF,'IOS f-@01 CO: 4'i'AM I t I 1'7PEtl t'@xF-,OSL)F@E W-,: I c; H I' L@ll: E--
F-f4!ori(' (even t @, y i 1eq) TTME
Water' 4.(>(> 0 Is 9 70
.i-o Uncertai.nties
l'o understand the meaning of the (:ILtarititative exposure estimates oresented
z.bo%,e, i.t i.s no-cesi?,4ry tc. consider the t..,,Py asst.taipticins in derivin(] thk-oii.,
i,iid the uncertainties associatc-.J with those assumptions
- A ke- assumption is that the concentrations specified rLr
environmental media represent the true concentrations to which P?Ople
will be exposed during the period of exposure. Actual contaminant
concentrations will liP.,.ely vary ikcross both time and space.
- The-selection of exposure scenarios will also have a significant
influence on predicted exposures. Actual exposures to members of any
specified population will vary in accordance with the degree to which
they participate in the activities described by the exposure scenarios.
- Similarly, the numerical parameter values applied to each exposure
s,cenaric will have a ff#arleed effect on exposure. The default valuoie
provided are estimates for the entire U.S. population. Various
demographic factors (including geographic region, rural or urban setting,
socioeconomic status and ethnic heritage) may call for significant
alterations in these values.
The uncertainty analyses peovided as an cotidh by RISK*ASSISTAt4T can
exposures
calculated using standard (averag* or r*asonable worst-c&46) numerical
parameter values for each scenario you hove seloct*d. They can also providec
information on the way in which your selection of exposure *canaries -
influenc6s the exposure estimates you hay& calculated.' Because chemical
concentrations will vary across space and time, and peoples activities that
result in exposure are also highly vaelable, the actual range of possible
exposures for your site is greater than the range covered by RISK*ASSISTANT's
uncertainty analyses.
5.1 Uncertainties Regarding Exposure Parameters
One estimate of the uncertainty astociated with the exposur* estimates
presented.above is provided by an examination of the ways in which using
alternative values for numeelcal exposure parameters can change the resulting
exposure values. The following table prwsents alternative exposure
predictions (ADEs and LADES) for each chemical, when exposure is calculated
using 1) Average default values for all expasuee paeametees, and 2) Reasonable
k@st-Caso values for all parameters. In each case, the resulting ADE or LADE
is Presented as a poecent*q* of the corresponding ADE or LADE calculated using
t.teer-specified parameter values. Those values indicate the range of exhumes
@hat might be expected to occur for each scenario, and the position of the
e,:Po%ure calculated by the user wi.tnin (or possibly outside of) this range.
P-nllowinq this table are additional tablet that present, for each scenario,
tnese alternative parameter values, both in absolute units and as a percentage
of the parameter values actually used.
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Document 7 f:/Week-36/BX003205/EXPOSURE CALCULATIONS/kuwait assessment of potential groundwater conta:01029715474153
Control Fields 17
File Room = sep96_declassified
File Cabinet = Week-36
Box ID = BX003205
Unit = OTSG
Parent Organization = HSC
Folder Title = EXPOSURE CALCULATIONS
Folder Seq # = 19
Subject = KUWAIT ASSESSMENT OF POTENTIAL GROUNDWATER CONTA
Document Seq # = 1
Document Date =
Scan Date =
Queued for Declassification = 01-JAN-1980
Short Term Referral = 01-JAN-1980
Long Term Referral = 01-JAN-1980
Permanent Referral = 01-JAN-1980
Non-Health Related Document = 01-JAN-1980
Declassified = 02-JAN-1997