Document O3YdKE1vV194RRy7rd98yGqmQ

June 1, 1970 Herbert B. Stoklnger, Ph.D. Chief. Laboratory of Toxicology and Pathology Bureau of Occupational Safety and Health Department of Health. Education and Welfare 1014 Broadway Cincinnati, Ohio 45202 Dear Herbs In reply to your letter of May 28, I am mailing under separate cover today a atatus report on our ohronlo studies with three polychloroblphenyla. X enclosed with this letter a summary of the status of the data which we think reflects Dr. Calandra's Interim reports. Briefly, two-year chronic feeding studies were begun in dogs In May, 1969. The materials under test are Aroclor 1242 ( biphenyl chlorinated to the extent of 42J<): Aroclor 12$k (biphenyl chlorinated to the extent of 54%)j and Aroolor 1260 (biphenyl chlorinated to the extent of 60). These are being fed at the levels of 1, 10 and 100 parts per million. Dr. Calandra's status report for the dog studies Is dated following 11 months of administration as of April 23, 1970. ' Each material Is also being administered to rata for two years at the same levels. The rat studies also started In May, 1969 tut we added 30 additional rats In July to provide for Interim sacrifice at three months, bIx months and twelve months. Dr. Calandra's reports then show the effects on the animals after nine months of feeding with comments on micropathology on those animals sacrificed after three month and alx month periods. MQNS 090673 Herbert B. Stoklnger, Ph.D, June 1, 1970 Pag* Two W foal that tha raaulta to data Indicate that tha throw taat matarlala ara about tha same order of toxicity aa DDT. Z will ba happy to dlacuaa tha raporta with you by phono and will try to raaoh you thla waak. Bast personal regards. Sincerely, SPWsJu Enclosure Dinar P. Wheeler Manager, Dnvlronmental Health MONS 090674