Document DdY4M3znj33KrV0BYoj4Xz1M5

August 4, 2005 n: h' DuPont Haskell laboratory for Health and Environmental Sciences Elkton Road, P.0. Box 50 Newark, DE 19714-0050 Via Federal Express Document Processing Center (Mail Code 7407M) Room 6428 Attention: 8(e) Coordinator Office of Pollution Prevention and Toxics U.S. Environmental Protection Agency 1201 Constitution Ave.,NW C o n fclin W O ` Washington, DC 20460 - >(-3 ODI ^51 <?H ra*-o c:j i r* CD O :.T 3 - '3 o Dear 8(e) Coordinator: 8EHQ-0381-0394 Ammonium Perfluorooctanoate This letter is being submitted as a supplement to information we communicated to the Agency on January 10, 2005. This evaluation is part of an ongoing study, "Ammonium Perfluorooctanoate: Cross-Sectional Surveillance Of Clinical Measures of General Health Status Related to a Serum Biomarker of Exposure and Retrospective Cohort Mortality Analyses in a Polymer Production Plant" of over 1,000 employees at our Washington Works plant. As described in communications to the Agency on January 10, 2005, study participants were divided into four categories based on job histories: Assignment 1. Currently working in PFOA areas 2. Formerly worked in PFOA areas 3. Occasionally works in PFOA areas 4. Never assigned to PFOA areas Number 259 264 160 342 Median PFC 0.49 0.20 0.18 0.11 Study participants' current residences were plotted on a map of Wood County, WV and Washington County, OH by category level of serum PFOA, using EPI INFO software and geocoding based on the U.S. Census TIGER database. The PFOA serum level categories (in ppm) were: from O to <0.1 from 0.1 to <0.5 from 0.5 to <1.0 from 1.0 to <5.0 from 5.0 to <10.0 89050000533 E.l. du Pont de Nemours and Company No clear associations between serum level and proximity to plant site were apparent in the initial plot of all study participant residences by measured PFOA serum level category and whether they ever worked in a job division that had likely potential for exposure. However, when only current addresses of employees that were never assigned to divisions with likely potential for PFOA exposure were plotted on the map, 6 of the 7 individuals with serum levels in the highest category for this group (between 0.5 and 1.0 ppm) lived within 5 miles of the plant site. Five of these seven individuals lived in a NNE direction from the plant (Ohio), the direction consistent with the prevailing winds of the area, and one individual currently resides west of the plant site (Ohio). The seventh individual in this group lives in the town of Parkersburg, W .V., approximately 10 miles from the plant. We emphasize that not all possible exposure sources have been identified and analyzed. When the residences of all study participants were plotted by relative exposure groups, (differences between individual measured PFOA serum level and the median value for their jobs expressed as percentages of the median value), participants with the highest relative values (i.e., people in the high end of the range of PFOA serum levels for their job) appeared equally distributed within and outside the 5-mile radius from the plant. However, participants in the lower relative exposure groups were much more likely to be found outside the 5-mile radius. A copy of the final report of the larger ongoing study referred to above will be submitted to the Agency when available. Sincerely, A. Michael Kaplan, Ph.D. Director - Regulatory Affairs and Occupational Health AMK/RWR/RCL: clp (302) 366-5260