Document 3eZpno9Ej2J9G3MkyjrDJdkLa
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Dr. Tf. S. Bovaa Ovena-Xllinole Glass Coap&ny Toledo, Ohio
Dear Dr. Bowes:
St was a pleasure to have had opportunity to dleouss the X-Lo problem with you and Hr. Hirth In Fitteburgh the other day and as keenly Interested in your proposals for further investigation of aay haaarde whloh sight be associated with exposure to dust of this material.
To eunaarits our discussion I aay state that in my opinion suoh an Investigation should include (l) an inspection of manufacturing prooesses at the new plant in Berlin, Kev Jersey, (2) a study of the behavior of X-Lo dust in ataospherlo suspension inoluding such features as the effeot of fcoaldlty, fsn&enoy to flocculate and settle, the relative proportions of fibres and particles in air floated dust, etc., and (3) dally exposure of a large nunber of experimental anioals to high concentrations of dust of this material to determine first, whether It oan be Inhaled into the lunge in significant quantities and second, whether it will produce serious pathological reaction.
On investigation of our situation here 2 believe we will be in a position to start such a study about January 1, 1945. By that tine we nope to have the necessary nunber of guinea pigs and white rats available. For the aonent our supply is very Halted.
Our engineer will plan to visit Berlin, Kev Jersey as soon as his schedule will permit and I also shall expeot to do so when 2 aa in the vicinity which should not bt too far distant. Vs will want to oollect several hundred pounds of dust in order to insure material of uniform oosposltlon for the entire experiment. Frobably as you sug gest dust froa the oolleotor systea in your faotory would bt satisfactory for the purpose unless it should be grossly oontaalnated with other dust. The axaot a&ount that we shall need would have to be deterslned after we experiment with it to dlsoover how. readily: it will produoe a dust oloqfd in our experlsental rooa. Z would suggest that you send ui about ten pound* of oolleotor dust for prellalnary Investigation.
. Ve should oonteaplate exposing at least 13p guinea pigs,
BO white rats and perhaps 10 rabbits 8 hours dally 6 days a week over a period of one or two years. The nature of the results would determine the duration of thu experiaent. Xf the one year results are negative or alnlaal it will be neoeseary to continue the exposure for at least
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Dr.* V tT. Bow es
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2- Koveobejr 27,
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another year In order to -take oertain that this nsterial does oct
slowly penetrate and aooucrulste within the .lunge to oauae chronic tissue reactions. Aa in previous experiment* this test will involve saorifioe of groups of exposed aninsle at intervals during the ex
posure; gross niorosoopic and cheolcal analyses of their tissues.
In view of the faot that there nay be eooe unooobined sill
in the aixturs X believe that 60 of the guinea pigs with a like nusbe
of undusted oontrols should be infected with tuberole bacilli to dis
cover whether there is any alteration of susceptibility to such infec
tion.
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The ooat of this experioent will be >6,000.00 a year plus the aecessaxy travel expenses of our engineer,forlplant^lnspectionl"
Should you desire to undertake it X would suggest that oayaent be o&de
quarterly to the Saranac Laboratory. You would, of course, supply the necessary dust for investigation. The Laboratory will beep you inform
of the progress of the work and on its coapletion furnish a complete report of all details of the study. Xt is hoped that the results say be such that you night wish to have us publish our findings but it 1* understood that nothing will be published without your authorisation.
Very truly yours.
LOOiRE oo to Kr. A. C. Hirth
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Leroy U. Gardner, H. P.
Pirector
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