Document omBro7ZBY7V1M283r0rw18e53

January 14, 1957 D r. W. P . Pelz 1504 E a st C lark S treet. C h a rle s C ity , Iowa D ear D octor P elz: . ! I apologize hum bly fo r the long d elays that have c h a ra c te riz e d m y co rresp o n d en ce w ith you. X can only a sk fo r your ind ulgence. P erh ap s so m e re tu rn fo r you r p atien ce m ay be found in th e ad v ice w hich is contained in this resp o n se to your la s t le tte r of Jan u ary fifth . I b eliev e that you w ill find your e ffo rts to in v estig ate the re la tio n sh ip of te tra e th y l lead to lung c a n c e r to be w holly u n p rod u ctive, and I su g g e st that you turn your in te re s t in th is highly sig n ifica n t p ro blem of public, h ealth in som e m o re p oten tially productive d ire ctio n . M y re a so n fo r thi3 opinion m ay be e x p re s s e d b rie fly , and I hope, b e n e ficia lly . F i r s t , is th e fa c t that no sig n ifica n t p rop ortion of our population is exposed to te tra e th y l le a d . Only p erso n s engaged in the m an u factu re and the handling of the con cen trated m a te ria l a re su b jected to such exp o su re in m o re than th e o re tic a l t r a c e s . {Of the e ffe c ts of such exp o s u re , m o re "w ill be said la t e r .) T etra eth y l le a l in autom obile and a ero n a u tica l fu els is burned to in organ ic lead com pounds, and it is not p o ssib le to find te tra e th y l lead a s such in the atm o sp h ere c l u rban ce n te rs in w hich tr a ffic is d e n se . It is th e re , th e o re tic a lly , only at tim e s and under c irc u m sta n c e s in which the com bu stion of the fu el is poor - in sta rtin g up a co ld m o to r, fo r e x a m p le, a little te tra e th y l le a d in the unburned gasolin e. Seco n d , in M ex ico , as in the U . S . A . , a f a ir ly la rg e p ro p e rtie s, o f the g aso lin e con tain s tefcraetrryi le a d , and the en v iron m en tal conditions th ere a r e , in th is r e s p e c t, co m p arab le to th ose in the U .S .A . T h ird , is th e f a c t th a t m a n y th o u sa n d s o f p e r so n s h a "re beer* s u b je c te d to the inhalation of in organ ic compounds of lead fo r m any g en era tio n s. Instead of an a sso cia tio n of th is exp o su re with a re la tiv e ly high in cid en ce of lung c a n c e r , the s ta tis tic s , w hich, ad m itted ly , a r e inad equate, su gg est th at e x p o su re to , and a b s o r p tio n o f, le a d , ten d s to in h ib it r a th e r than to induce o r a c c e lle r a te , ca n c e r. On th is b a s is , u n sa tisfa cto ry as it m ay be, 0009326 Dr. W. P. Pelz - (2) - January 14, 1957 in v e stig a to rs, and, m o3t re ce n tly , B la ir B e ll and h is a s s o c ia te s in L iv erp o o l used lead com pounds, o v er som e co n sid era b le period , in the therapy of m alignant d ise a se . They accom p lish ed no v ery useful p u rp ose, but they w ere encouraged to continue th e ir w ork even a fte r th e re seem ed to be sca n ty hope of s u c c e s s , by a few in sta n ce s in w hich tum ors re g re ssed . , F o u rth , se v e ra l thousand p erson s have been engaged in.the m anufacture of te tra eth y l lead sin ce 1923, the nu m bers having grow n m o re o r le s s stead ily 3ince 1926. The m edical supervision of these m en has been m o re com p rehensive than th at provided fo r any oth er group c f ind ustrial em ployees over any such period of tim e, so fa r as m y exp erien ce goes. W ithin this group, w hose re sp ira to ry exp osu re to tetra eth y l lead has been the g re a te st and m o st continuous in a ll hum an ex p e rien ce, has been u tte rly in sig n ifican t fro m the a sp e ct of m alignant d ise a se , including pulm onary ca n c e r. This rep resen ts my c ritic is m of your exp erim ental hypothesis. Because of it, I s u g g e s t th at you m ay co n sid e r the .ad v isab ility of w orking with som e e th e r m a te r ia l. My c r itic is m has nothing to do w ith m y w illin g n ess to se e th at you a r e p rovid ed w ith a m o d est quantity o f -tetraeth y l le a d . I art. m e re ly tryin g to head off what seem s to m e to be unprofitable u ses of a d a n g ero u s m a t e r i a l, so a s to aid in th e lim ita tio n o f it s u se to p ro d u ctiv e purposes. S in c e re !" yo RAK ef R obert A. Kehoe, M . D. KF 0009327