Document jBOLJdRGE90w4dOy3D6JeyewQ

co T H O M A S W. G E O R G E S , J R . , M .D . SECRETARY OF HEALTH DEPARTMENT F HEALTH P. O. B O X 90 H A R R I S B U R G 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 mg' is obtained by injestionj provided that there is no increase in atmospheric levels. (Atmospheric levels = 1.5 l-^g/mS.-- Cincinnati data.) Thus: The amount that can be safety absorbed is: ingestion = 0.5 x 0.1 = 0.050 inhalation = 1 . 5 x 2 0 x 0 . 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 N14895 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 P'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 KT 0 13 sU i