(EPA-823-R-00-002)
Errata
\) page 4S5-.  Replace paragraph under Human Health Section for'Methylmercury with the following:
EPA is recommending that the Programs and Regions use 0.1 ug/kg/day as an interim RfD for
methylmercury until the Agency has had an opportunity to review the work of the National Academy of
Science (NAS).  NAS is performing an independent assessment of the Agency's reference dose (RfD) for
methylmercury (EPA 1999).                                 '.
[U.S. EPA. 1999. Memo: Transmittal of Interim Agency Guidance on the Use of Methylmercury
Reference Dose in Making Risk Management Decisions.  From: Peter D. Robertson Acting Deputy
Administrator, To: Assistant Administrators, General Counsel, Inspector General, Chief Financial
Officer, Associate Administrators, Regional Administrators and Staff Office Directors (April 19, 1999)].

2) pages 7, 23, 35, 45, 61: Add to Human Health: Oral slope factor: 2.0 per mg/kg/d based on
environmental mixtures of PCBs in aquatic organisms (EPA 1996)
[U.S. EPA. 1996. Cancer Dose-Response Assessment for Application to Environmental Mixtures.
EPA/600/P-96/001F.  Washington, DC].

3) The table below provides the latest World Health Organization (WHO ) toxic equivalent factors
( TEFs)  for dioxins, furans, and coplanar PCBs. They are more recent than those cited in this document.
Congener
2,3,7,8-TCDD
1,2,3,7,8-PeCDD
1,2,3,4,7,8-HxCDD
1,2,3,6,7,8-HxCDD
1,2,3,7,8,9-HxCDD
1,2,3,4,6,7,8,-HpCDD
OCDD
2,3,7,8-TCDF
1,2,3,7,8-PeCDF
2,3,4,7,8-PeCDF
1,2,3,4,7,8-HxCDF
1,2,3,6,7,8-HxCDF
1,2,3,7,8,9-HxCDF
2,3,4,6,7,8-HxCDF
1,2,3,4,6,7,8-HpCDF
1,2,3,4,7,8,9-HpCDF
OCDF
3,4,4',5-TCB(81)
3,3',4,4'-TCB(77)
3,3',4,4',5-PeCB(126)
3,3',4,4',5,5'-HxCB(169)
2,3,3',4,4'-PeCB(105)
2,3,4,4',5-PeCB(114)
2,3',4,4',5-PeCB(118)
2',3,4,4',5-PeCB(123)
2,3,3',4,4',5-HxCB(156)
2,3,3',4,4',5-HxCB(157)
2,3',4,4',5,5'-HxCB(167)
2,3,3 ',4,4',5,5'-HpCB(l 89)
Toxic Equivalent Factor (TEF)
1
1
0.1
0.1
0.1
0.01
0.0001
0.1
0.05
0.5
0.1
0.1
0.1
0.1
0.01
0.01
0.0001 '
0.0001
0.0001
0.1
0.01
0.0001
0.0005
0.0001
0.0001
0.0005
0.0005 ;
0.00001
0.0001
Van den Berg, et. al. 1998. Toxic Equivalency Factors (TEFs) for PCBs, PCDDs, PCDFs for Humans
and Wildlife. Environ. Health Perspect. 106(12):775-792.

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