Document v61j743Gjemk1QYa1YawqJm8

5M a y $ 1 9 4 9 Mr. Manfred Bowdiieh, Director of Health and Safety, Lead Industries Association, 420 Lexington Avenue, lieu f o r k C i t y 17 ' Dear Manfredi I n r e s p onse to your lette: of Aorii ;s q u e s t i o n I a m glad to point out that the sta .ement rade on the authority of Doctor B a i l e y m the M a y i s s u e of ;ne ra,xa t o u r n a i subs tant ially i n c o r r e c t It is q u i t e wJ*- u. > /~ i a t the c r a n k - c a s e oil f r o m e n g i n e s us i n g l o a d e d g a s o l i n e lias l e a d i n it* I n g e n e r a l , however, the lead derived from the fuel has been decomposed and exists in inorganic form, w i t h the e x c e p t i o n c.f m i n u t e traces cf tetra ethyl lead. A very considerable number* of observations have b e e n m a d e on crank-case oil, and the b e s t ci mr knowledge n o i n s t a n c e has b e e n f o u n d of signi- ficant concentrations cf straethyl lead* It would b e recognized, of course, that to the extent that the fuel is unburned and mixed with crank-case oil, snail quantities of tetraethyl lead might occur therein, along with the gasoline, as a contaminant. Actually, however, the concentrations have been tco small to be of significance. Analyses have shown, moreover, tlmt new oil before being Introduced into the crank-case contains small quantities of lead compounds, and therefore net all of the lead in such oil is derived from the f u e l . I do not suggest that crank-case oil is the best of all possible materials to use as the vehicle f or insecticidal sprays for animals* F o r this reason x am not much disturbed by any allegations that would render such a solvent unpopular. On the other hand, I think the hogs can be regarded as quite safe from the viewpoint of percutaneous absorption of tetraethyl lead from any source* Cordially yours, iAM of gober u 'A * lienoe, H* D * H E 0014976