Document Ejg9Rd36Qb0RD6vxQYdmoR6R

DuPont Haskell Laboratory DuPont Haskell Laboratory for Toxicology and Industrial Medicine Elkton Hoad, P.Q. Box 50 Newark, DE 19714-0050 October 6,1999 Via Federal Express Document Processing Center (7407) Attention: F.Y.I. Coordinator Office of Pollution Prevention and Toxics U.S. Environmental Protection Agency - 401 M Street SW Washington, D.C. 20460-0001 Dear F.Y.I. Coordinator: Lead Acetate {trihydrate) (CAS# 6080-56-4) This letter is to inform you of the results of. some immunologic research, which we recently became aware of, with the above referenced material. In this study, 2 groups of pregnant Sprague-Dawley rats (Crl:CD BR) rats were administered lead acetate in their drinking water at concentrations of 0 or 250 ppm. At parturition, lead acetate treatment was ceased and animals were switched to normal drinking water. The offspring were culled at 10 days of age to 4 males and 4 females per litter. Offspring were weaned at 21 days of age. At 5-weeks of age, two assays, the Deiayed-type Hypersensitivity Response (DTH) and anti-KLH IgG antibody ELISA were performed. The results indicate that the imfnundtoxic effects of lead can be measured in very young animals after in utero exposure to lead. In addition, a gender difference was noted in that females displayed a depressed DTH response whereas males did not. Previous published studies have indicated that when pregnant Fischer rats Were exposed to 250 ppm lead acetate in the drinking water and their offspring maintained on normal drinking water for 13 weeks, lead acetate produced a statistically significant decrease in the DTH response of offspring. It is well documented in the literature that lead is known to have an irnmuno-modulatory effect in adults and in animals exposed during gestation. This research shows that it can be detected in 5-week old rats. These findings will be published in a forthcoming manuscript. Sincerely, A. Michael Kaplan, Ph.D. Director - Regulatory Affairs AMK:alw (302) 366-5260 DUP040011147 TSCA F.Y.l Submission: Lead Acetate (trihydrate) CAS # 6080-56-4 Bcc: P.V, Tebo M.L. Rees A.V. Malinowski S.L. Fidance A.M. Kaplan G.S. Ladies S.E. Loveless R.W. Rickard Technical File Dr. Rodney Dieted Cornell University C5135 VMC, Box 5 Ithaca, NY 14853-6401 Lee Salamone/Carolyn Leep Chemical Manufacturers Association 1300 Wilson Boulevard Arlington, VA 22209 DUP040011148