Chris,
It is the life time cancer risk. This is used in TOX 11 to calculate
Index Dose for benzene, using 1E-5 (ie 1 in 100,000 probability).
Regards,
Kevin Privett.
Dr Kevin Privett
Principal Geo-Environmental Consultant
Hydrock Consultants Ltd
Over Court Barns
Over Lane
Almondsbury
Bristol
BS32 4DF
Tel: (01454) 619533
Fax: (01454) 614125
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Cell phone: (07799) 430870
Offices in Bristol, Plymouth, Northampton, Stoke-on-Trent.
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-----Original Message-----
From: Contaminated Land Management Discussion List
[mailto:[log in to unmask]] On Behalf Of Chris
People
Sent: 22 November 2005 12:20
To: [log in to unmask]
Subject: Slope factors
In a post on the geomem forum the poster cites GSI that slope factors
may
be derived from Index Doses using the formula: :
S.F = Target Risk / Index Dose
(http://www.geomem.com/forums/rbca/posting.php?
mode=quote&p=19&sid=dd94bf25eebd19827df6de7f48e9b546)
As an example a Dutch Index dose is converted to SF:
S.F = 1E-4 / 0.0033 = 0.03(mg/kg/day)^-1
Could anyone let me know what this 'Target Risk' is, and where it comes
from? Apologies if this is a no-brainer.
Also how do the regulators feel about accepting DQRAs for Tox report
contaminants that have been undertaken on RISC or RBCA using this
method?
In the absence of other free sources of tox data would it be acceptable
to
reverse the equation and derive an index dose from a SF?
Thanks,
Chris
Chris People
Owen Williams Consultants
01273 897160
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