Document mpMyp5XR7jwO03Dnmkp1X0xV4

M*ONWHALTHoPpENNs CO m j&t m THOMAS W. GEORGES, JR., M.D. SECRETARY OF HEALTH DEPARTMENT OF HEALTH P. O. BOX 90 HARRISBURG 17120 April 27, 1967 Robert A. Kehoe, M. D. Professor Emeritus of Occupational Medicine Kettering Laboratory Eden and Bethesda Avenues Cincinnati, Ohio 45219 Dear Dr. Kehoe Dr. Brandt informed me of your request for a copy of the calculation we discussed in my office. The following is the calculation: Assume that no adverse effects occur when 0.5 nig is obtained by injestionj provided that there is no increase in atmospheric levels. (Atmospheric levels = 1.5 Pg/mS---Cincinnati data.) Thus: The amount that can be safety absorbed is: ingestion = 0.5 x 0.1 = 0.050 inhalation = 1.5x20x0.1= 0.003 inhalation-ingestion = 1.5 x 20 x 0.45 x 0.1 = 0.001 .054 mg/day Total The average amount absorbed through injestion is: 0.3 x 0.1 = 0.030 mg/day Robert A. Kehoe, M. D 2 April 27, 1967 Thus the amount that can be safely absorbed through inhalation = 0.054 - 0.030 = 0.024 mg/day Let X = allowable atmospheric concentration Thus: 0.024 = X (20 x 0.1 + 20 x 0.45 x 0.1) X = 8.3 l^g/m^ Please let me know if you have any further questions con cerning this. Sincerely, Victor H. Sussman, Director Division of Air Pollution Control HE 00 Ui