Document LpKyGQKrj5EBy5z9geDmgmoK5

:mttaXM* ..n-f,. \ lrfiii UMIOK E. I. ou Pont de Nemours E Company CC : G. J. Scopes,MD, E.'.p.P.el,; J.L. Parsons, Engineering, END La1 Wilmington, Delaware wan J. R. Allen, Engineering, DSD INGINCtAINO OCmUtTMCNT July 11, 1963 ADRIAN tiXT'TCII MEDICAL SECTION CHXXSRS W0R2S DUST CONTROL PROGRAM V/e are enclosing a copy of the results from the airborne dust sample made at Construction Division site locations during the month of June, 196.1. Also included are tho procedures used for tho evaluation of airborne dust samples performed by Mr. Felix Stain and Dr. Morton Corn of the University of Pittsburgh, Graduate School of Public Health. In evaluating the sito locations whose quantitative analysis indicated particle counts in excess of 1 MP/CF, v/e found the primary cause to be drafts produced from open doors and windows. Tho provided exhaust systems viere not functioning in full potential due to the drafts blowing the small particles avray from pick-up point and making them airborne. Other producers of airborne particlos v/ore in the handling of calcium silicate block material from shipping carton through fabrication process. In isolated instances, hand suits contributed a percentago of tho airborne particlos. The Old Hickory Construction Mono Spray sanple dated 6/13/6$ substantiates the need for improving spray applying equipment of asbestos fibrous materials. The 6/14/ofi sample was taken of the employee opening Mono Insulation material bags and changing spray machine. V.'e anticipate this information will be of interest to you and if we can be of any further service, pleas* contact ths writer. CONSTRUCTION DIVISION //. K. E. Keuper Division Safety Supt DUP 0901034 RECEIVED KEX/dla Enclosures JUL151SS3 HASKELL LAB. CTTCM THINGS TO* SCTTCN UVINO . , . THNOUGH CHCMISTAY DU 022430 SUMMARY OK P A R T IC LE AND F IB E R COUNT FOR J u n e , 1 9 6 8 SAMPLES DU 022431 SUMMARY OF P A R T IC LE AND F IB E R COUNT (A Jrf >4 1 0) as 3 O A 0) r4 O o +1 srt o +1 r* fs o * O o U pft AM w o Eb o +i Gu -4 q4 u OS + 1 M VS a. 0 1 r* 99 &V fN O 2 OS 3 ttwaJ6. e 2 VS o r* VS VI O VS . rs 4V < c 3 oH o o <N 0a . 09 CJ VI +1 +1 vn CD vs H u 0e) -4 4J Sft a o 3 n * (ft 09 vs a a ft -* oa. o >4 fft u H + i u ft m o* n M +i << eft 0 1 o p*1 3 a 4J pft i lb 0 m VS s 3 *4 .4 w 10 J 4# 9 3 0 4 > r> r* * H II ? 5 2 <ft w ij <9 u VS (A H g c ft H *4 z 0 09 ij 09 m <ft I* *0 aM 1 i VS i r* --B" i a jA____ CA uCs 3 3 01 n ft M f* in CN DUP 0901036 DU 022432 pkoc-^i-Riji os:~.3 -or tr,:-: r-v-icv. or ,\:.\zo?::z ;ist s.^-l-hs The n.illipora" filter ** first visually examined to detect any loose dust or uneven dust deposition. In the few cases where the filter deposit did not pass this examination it was necessary to resuspend the collected dust in distilled water and refilter this suspension on VF-Millipore filter to assure an even dust distribution over the whole filter area. A pie shaped segment of the millipora filter was then placed on a microscope slide and rendered completely transparent with Cargille certified index of refraction liquids. In our tests we found Cargille liquid of an index of refraction of 1.500 to be best suited for this purpose. The counting of the dust particles and the counting and sizing of the asbestos fibers was performed with a Zeiss Photomicroscope using Phase Contmft Illumination. The objective was a Zeiss Heofluar Ph 63x phase contrast objective with a numerical aperture of 0.90. The eyepiece contained a Porton graticule<has a magnification of 20x and the intermediate magnification of the Zeiss Photomicroscope (called optovar) increased the magnification by an additional factor of 1.6x. Thus, the total working magnification was 2016x and the resolution was approximately 0.35.U, making the detection of particles and fibers possible down to a size of 0.30u diameter. In the evaluation procedure all particles and fibers inside of the field, of the Porton graticule were counted and the fibers were grouped by fiber length into 3 categories (less than Su, 5-10ji and larger than 10n). This procedure was repeated for a number of randomly selected fields on the face of the filter. Because only a portion of the total filter area was evaluated by this method, it was necessary to correct the eou ntby the ratio of the total filter area to the evaluated area. The resultant particle or fiber number was divided by the volume of the air sample and concentration was expressed as MPPCF (Millions of Particles Per Cubic Foot). The statistical" reliability of the evaluation was expressed as the standard deviation* of the concentration and is tabulated as the s Standard Deviation Is taken as STTwhere N is the particle or fiber c DUP 0901037 DU 022433 + value after each nuiv-bcr cor.cencration. Ine procedure outlined follows in its essential points the recorw.endatior.s given by Jereniah R. Lynch and Howard E. Ayer in "Measurement of Asbestos Exposure" Journal of Occupational Medicine, January 1963, Vol. 10. Procedure and Counts by; Felix Stein .Checked by: Morton Corn DUP 0901038 DU 022434