Document x5nYKzbpp1v18z92J8kB56e8J

NORTHERN KENTUCKY OFFICE SUITE 340 1717 DIXIE HIGHWAY COVINGTON. KENTUCKY 41011-4704 606-331-2838 513-381-2838 FAX: 513-381-6613 Robert A. Bilott (513) 357-9638 bilott@taftlaw.com . \FT, STETTINIUS & HOLLISTER Li. 1800 FIRSTAR TOWER 425 WALNUT STREET CINCINNATI, OHIO 45202-3957 513-381-2838 FAX: 513-381-0205 www.taftlaw.com M CIEVELANO OHIO OFFICE 3500 BP TOWER 200 PUBLIC SQUARE CLEVELAND. OHIO 44114-2302 216-241-2836 FAX: 216-241-3707 COLUMBUS, OHIO OFFICE 21 EAST STATE STREET COLUMBUS. OHIO 432154221 614-221-2838 FAX:614-221-2007 _ I I 7 3 March 8, 2002 TELECOPY AND REGULAR U.S. MAIL Donald S. Welch Regional Administrator U.S. Environmental Protection Agency Region III 1650 Arch Street Philadelphia, PA 19103-2029 Janet E. Sharke, Esq. (3RC30) U.S. Environmental Protection Agency Region III Office O f Enforcement, Compliance and Environment Justice (Mail Code 3EC00) 1650 Arch Street Philadelphia, PA 19103-2029 Thomas V. Skinner Regional Administrator U.S. Environmental Protection Agency Region V 77 West Jackson Blvd. Chicago, IL 60604 Kelley Moore (W6-15J) U.S. Environmental Protection Agency Region V 77 West Jackson Blvd. Chicago, IL 60604 rs) CTD CuZ>3 -- ~ o c~> en --Im :'2 m oo Re: Public Health Concern Involving C-8 Drinking Water Contamination In West Virginia And Ohio_________________________________________ Ladies and Gentlemen: As indicated in our November 1,2001, letter to the United States EPA, ATSDR, and the West Virginia Department o f Environmental Protection, our law firm is currently working with two other law firms in West Virginia in the representation of numerous individuals who have brought a class action lawsuit against E.I. duPont de Nemours and Company ("DuPont") and the Lubeck Public Service District o f Wood County, West Virginia ("LPSD") in connection with the contamination o f human drinking water supplies with ammonium perfluorooctanoate (a/k/a APFO/FC-143/PFOA) ("C-8") originating from DuPont's Washington Works in Wood County, West Virginia. A copy of our clients' Amended Complaint in that matter previously was forwarded to your agencies. As indicated in that Amended Complaint, our clients are concerned that there is a current, imminent, and substantial threat to their health based upon the past and current presence o f excessive levels o f C-8 in local drinking water supplies. We have asked the T - mo cei 000054 March 8, 2002 Page 2 Circuit Court in West Virginia to order, among other things, appropriate medical monitoring for those who have been exposed to C-8 in their water. It has come to our attention that your agency is in the process o f finalizing a Consent Order with DuPont to provide for alternate water supplies to those whose drinking water has been contaminated with C-8 originating from DuPont. It also has come to our attention that your agency has not been able to obtain DuPont's agreement to immediately provide any alternative water unless the levels o f C-8 exceed a 14 ppb level advocated in a January 24, 2002, report prepared by DuPont's consultant, Environ. As indicated in the attached document prepared by Tetra Tech, which has thoroughly reviewed the same information referenced and relied upon in DuPont's Environ report, our clients believe that the 14 ppb number selected by Environ is in error and substantially underestimates the potential health threat to those drinking C-8 contaminated water. The current data actually confirms that C-8 levels in excess o f 0.3 ppb in human drinking water may present an imminent and substantial endangerment to human health and the environment. Thus, on behalf of our clients, we request that your agency consider the issues raised in the attached document from Tetra Tech before agreeing to any Order with DuPont that does not require DuPont to immediately provide alternate drinking water to those exposed to C-8 levels in excess o f 0.3 ppb. Please let us know if you have any questions about any of the issues raised in the attached document. Thank you. iobert A. Bilott RAB/mdm Attachment cc: Armando Benincasa, Esq. (WVDEP) Greg Smith, Esq. (Ohio EPA) 000055 March 7, 2002 Page 1 Tetra Tech, Inc. DISCUSSION POINTS RELATING TO THE ASSESSMENT OF HEALTH RISK FROM EXPOSURE TO AMMONIUM PERFLUOROOCTANOATE (PFOA) The following issues are critical to the development o f a public health protective assessment of human health risk for populations exposed to ingested PFOA. The discussion is particularly relevant to an evaluation o f a recent assessment o f risk to human populations exposed to PFOA ( A Hazard Narrative for Perfluorooctanoate (PFOA). prepared by Environ International Corporation for DuPont, January 24, 2002). I. Relevance of the PFOA study in cynomolgus monkeys to human health risk assessment The following issues relate to the interpretation o f a six-month study in cynomolgus monkeys dosed with PFOA (Covance 6329-231, December 18, 2001). This study formed the basis for the calculation o f a drinking water criterion proposed in DuPont's Environ report. A. Severity of the endpoint Severe toxicity was reported in the cynomolgus monkey study. The use o f severe toxicity as an endpoint from which to calculate safety levels is not consistent with EPA practices and is not adequately protective of public health. A critical endpoint that could be used quantitatively in development o f an RfD was not identified in the cynomolgus monkey study. B. Mode or mechanism of action The mode or mechanism o f action for the severe toxicity exhibited by the nonhuman primates monkeys has not been reported. The lack o f such information leaves open the possibility that as yet undiscovered effects specific to primates may be occurring at dose levels much below those used in this cynomolgus monkey study, adding great uncertainty to any assessment of human health risk. C. Humans may be an especially sensitive species Rats tolerate PFOA toxicity better than monkeys and monkeys may eliminate PFOA more efficiently than humans. Since elimination o f PFOA is a major factor in determining species differences in toxic response, humans, which most likely possess the same critical endpoint as nonhuman primates may be the more sensitive to PFOA toxicity than any of the experimental animal models. D. The absorbed PFOA dose in the monkey study may be in question There is evidence that PFOA is not well absorbed in the rat gut. There may also have been poor absorption in the gut with possible emesis in the monkey study. The possibility o f these effects is a further uncertainty in extrapolating to humans. 00005 / March 7, 2002 Page 2 II. Drinking Water Criterion Calculation Tetra Tech, Inc. The issues described above regarding the PFOA study in cynomolgus monkeys indicate that the study should not be used as the primary basis in deriving a level o f PFOA in drinking water that is safe for human consumption. The monkey study should, however, be considered a supplemental study indicating a need for a very conservative approach to the development o f a safe exposure level for humans. If a chronic rat study is used to derive a safe level o f exposure in drinking water using EPA procedures, a drinking water criterion o f no higher than 0.3 parts per billion (ppb) is obtained using a benchmark dose response, an uncertainty factor of 30,000, and a relative source contribution factor o f 0.2. III. Assessment of Cancer Risk In addition to tumors o f the liver, rodents dosed with PFOA exhibit testicular and pancreatic tumors. While it is not clear whether PFOA induced tumors of the liver occur in exposed human populations due to biochemical differences between rodents and humans, the mechanism o f action of tumors at the two other sites are different than for the rodent liver and their relevance to human health risk assessment is unknown. In accordance with the recommendations o f an expert panel convened to consider testicular tumors, testicular tumors should be considered legitimate endpoints for a cancer risk assessment in the absence o f evidence to the contrary. For similar reasons, pancreatic tumors attributable to PFOA exposure to rodents should also be considered a legitimate endpoint for cancer risk assessment. 000057