TCE_Guidelines

APPENDIX F
	Range of TCE Values Cited by NYS DOH and EPA After Reviewing Numerous Scientific Studies				TCE Guidelines Used By Various Agencies
	DOH*		EPA*		EPA		EPA Region 2	EPA Region 3	EPA Region 6	EPA Region 9		California Environmental Protection Agency	Colorado Department of Health and Environment	New York State Department of Health
	Less Conservative Value	More Conservative Value	Less Conservative Value	More Conservative Value	"Old Withdrawn" Value*	Proposed Draft Target Indoor Air Concentration*		Risk Based Concentration	Human Health Medium-Specific Levels	Preliminary Remediation Goal*		Target Indoor Air Concentration	Screening and Cleanup Levels*	Pre-October 2003 TCE Air Guideline	Post-October 2003 TCE Air Guideline*
Toxicity Value (Cancer Slope Factor) (mg/kg-d)^-1	-----	-----	0.02	0.40	0.006	0.40	EPA Region 2 does not have any set guidance. They make decisions on screening and cleanup levels on a site-by-site basis. At the Hopewell Junction site in NY, EPA Region 2 had previously used a TCE guideline of 2.7 but has recently lowered that guideline to 0.38 mcg/m³. The region’s goal is to get to 0 (non-detect).	0.40	0.40	0.40	0.007	0.007	-----	0.22	5
Concentration of TCE in Air Corresponding to a One-in-One Million (1*10)^-6 Cancer Risk (mcg/m³)	4	0.2	0.43	0.021	1.4	0.022		0.016	0.017	0.017	0.96	1.22	0.016
Concentration of TCE in Air Corresponding to a One-in-Ten Thousand (1*10)^-4 Cancer Risk (mcg/m³)	-----	-----	43	2.1	140	2.2		-----	-----	-----	-----	-----	1.6
Notes	*DOH states that this range of values is based on published estimates (from animal studies) and DOH-derived estimates (which take the quality of the data in the animal studies into consideration). DOH does not provide the underlying TCE toxicity values (cancer slope factors) that were used to derive these estimates.		*EPA’s draft toxicity assessment provides a range of toxicity values (cancer slope factors). These toxicity values are the basis for calculating TCE risk concentrations. However, the draft assessment does not actually provide these risk concentration estimates. The risk concentrations noted here were cited in an EPA Region 8 Technical Publication which states that the estimates were derived using EPA’s standard residential exposure assumptions (70-kg individual occupying a residence 24/hours/day, 350 days/year, for 70 years breathing 20 m³ of air per day)		*This toxicity value (cancer slope factor) was withdrawn from EPA’s Integrated Risk Information System (IRIS) in 1989. IRIS presently contains no quantitative toxicity information for TCE. The TCE risk concentrations shown here were cited in an EPA Region 8 Technical Publication which states that the estimates were derived using EPA’s standard residential exposure assumptions.	Table 2a, 2b, and 2c of EPA’s Draft Vapor Intrusion Guidance provide generic screening levels at cancer risks of 110-4, 110-5, and 110-6. The cancer slope factor is not explicitly stated in the table but a footnote to the tables states "the target concentration is based on the upper bound cancer slope factor identified in EPA’s draft risk assessment for TCE." The footnote also indicates that since the TCE assessment is still undergoing review, the slope factor and target concentration values for TCE may be revised further.				*The 2004 Region 9 Preliminary Remediation Goal (PRG) Table shows two different values for TCE. One value (.017) is derived from a toxicity factor of .4 and is based on conservative toxicity assumptions from the EPA’s 2001 draft toxicity assessment. The other value (.96) is derived from a toxicity value of .007 and is based on toxicity assumptions used by the State of California.			*Screening for TCE will occur at the level of 0.016 and clean up would be required at the level of 1.6 mcg/m3	Before October 2003, the state’s TCE guideline was at about 0.22 mcg/m³. This was known as the "no discernible impact" policy. In October 2003, however, DOH adopted a new guideline of 5 mcg/m³. DOH maintains that "the estimated increased human cancer risks associated with lifetime continuous exposure to 5 mcg/m³ are in the risk range (110E^-6 to 1*10E^-4) that is generally used by regulatory agencies when making decisions."
Source	Letter from Nancy Kim, Director of the Division of Environmental Health Assessment, to Dale Desnoyers, Director of Division of Environmental Remediation (October 31, 2003)		EPA Region 8 Technical Publication (January 26, 2005)		EPA Region 8 Technical Publication (January 26, 2005)	EPA’s "Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils" - Tables 2a and 2c (November 2002) http://www.epa.gov/correctiveaction/eis/vapor.htm	Personal communication with Jim Hackler from EPA Region 2. Information on Hopewell taken from an email from Congresswoman Sue Kelly to Region 2 Acting Adminstrator Kathleen Callahan and also an email f rom Hopewell resident Debra Hall.	EPA Region 3 Risk-Based Concentration Table (October 2004) http://www.epa.gov/reg3hwmd/risk/human/index.htm	EPA Region 6 Human Medium-Specific Screening Levels Table (December 2004) http://www.epa.gov/correctiveaction/eis/vapor.htm	EPA Region 9 PRG Preliminary Remediation Goals Table (October 2004) http://www.epa.gov/region09/waste/sfund/prg/index.htm		Cal-EPA report "Human-Exposure-Based Screening Numbers Developed to Aid Estimation of Cleanup Costs for Contaminated Soil" (November 2004) http://www.oehha.ca.gov/risk/pdf/screenreport010405.pdf	Colorado Department of Public Health and Environment. Press Release (August 20, 2004) www.cdphe.state.co.us/release/2004/082004.html	Article by Tom Wilber in the Binghamton Press and Sun-Bulletin. "Endicott Spills: Some Lose Aid for Cleanup as Rules Change" (December 14, 2004) http://www.pressconnects.com/special/endicottspill/stories/121404-136042.shtml Letter from Nancy Kim, Director of the Division of Environmental Health Assessment, to Dale Desnoyers, Director of Division of Environmental Remediation (October 31, 2003)