Document kDX52DVkO38mM3vw0V23Y911B

ACCt~riATI OIT OF LEAD I IT GARAGES UHEHE ETHYL GAS I S USES R ep o rt o f cm I n v e s t i g a t i o n C onducted i n th e S e r v ic e Ga rage of th e G eneral M otors R esearch C o rp o ratio n fo r th e P urpose of D eterm ining th e Amount and P ro p o rtio n o f Lead in th e Dust Accum ulating on th e F lo o rs o f G arages Used by C ars Running on E th y l Gas. S eptem ber 30 , 1923 Summary o f R e s u lts D octor J . C. Aub o f th e H arv ard M ed ical C o lle g e h a s s t a t e d t h a t th e a b s o rp tio n of 6 m illig ra m s o f le a d p e r day by th e human system o v er a p e r io d o f tim e i s s u f f i c i e n t to c a u s e le a d p o is o n in g . The r e s u l t s o f t h i s t e s t in d ic a te th a t in o rd e r fo r an employee o r p a tro n of th e g arag e under co n sid era tio n to absorb 6 m illigram s of le ad he would have to e x tra c t and r e ta in in M s system a l l of th e lead from 4 .4 grams o f the average flo o r d ir t . I f the re g io n im m ediately surrounding a 4 - c y lin d e r e n g in e , w hich was id le d on E th y l Gas ' throughout the p erio d o f th e t e s t , he l e f t out of c o n sid e ra tio n , i t would be n ecessary to e x tra c t the lead from 23.2 grans o f flo o r d ir t in o rd er to get 6 m illigram s. Method o f Malting th e T e st The S erv ice Garage o f the G eneral M otors R esearch C o rp o ratio n , which i s u s e d a s a b a s e f o r t h r e e Company tr u c k s and one s n a i l to u r i n g c a r f o r s e r v ic e and in w hich th e c a rs of 24 ex ec u tiv e s a re p ark ed d a ily , was s e t a sid e f o r th e . in v e s tig a tio n . The f lo o r o f th e g arag e was f i r s t swept th o ro u g h ly an d no f u r th e r sweeping was done in i t d u rin g th e p e rio d o f th e t e s t , w hich was 30 w orking d ay s. The tim e o f th e t e s t was fro m A ugust 8 , 1923, to Septem ber 26, 1923. A ll th e c a r s and tru c k s coming in to the garage w ere run on E th y l Gas w hich was su p p lie d to them from th e re g u la r su pply tank o f th e S erv ice Garage by means o f a lio . 4 E th y liz e r . The co m p o sitio n o f th e E th y l Gas u sed was a s follow s: -2 1 gallon gasoline 3 cubic cen tim eters te tra e th y l lead 1,5 cubic centim eters carbon te tra c h lo rid e During th e p e rio d of th e t e s t a re c o rd was kept fo u r tim es d a ily o f each c a r parked in the g arag e. This was done by checking the s t a l l s th a t w ere occupied a t 7 j 30 A .II., 10:00 A .II., 12:45 P .11,, and 3 :00 P .M ., and i t had f o r i t s p u rp o se th e e s tim a tio n o f th e number of au to m o b ile e n tra n c e s and e x its made d u rin g th e p e rio d of the in v e s tig a tio n . These n o ta tio n s w ere made a t su ch tim e s o f th e day th a t an approxim ation o f th e number of c a r s coming in to and 2es.ving th e garage co u ld be m ade. Ho r e c o r d w as k e p t o f th e Company t r u c k s and s e r v ic e c a r . H ear one c o r n e r of the g a ra g e a ''490" C h e v ro le t e n g in e was ru n i d l e on E th y l Gas f o r a p e rio d of 9 h o u rs each w orking day. This c a r was not moved d u rin g the e n tire t e s t . At the c lo s e o f the t e s t p e rio d the g a ra g e was a g a in swept in th e same thorough manner as a t th e b e g in n in g . The sw eepings from under and im m ediately around th e C hevrolet c a r th a t had been id le d during the t e s t were c o lle c te d sepa r a te ly from the r e s t . In the subsequent p a r t of t h i s re p o rt th e v a rio u s ly c o lle c te d sweepings w ill be d esignated as follow s: C h e v ro le t sw eepings - The f l o o r d i r t c o l l e c t e d j u s t aro u n d t h e C h e v ro le t c a r . G en eral sw eepings - The f l o o r d i r t c o l l e c t e d fro m a l l the g a ra g e f l o o r e x - cept th a t ju s t around the C hevrolet. - T o tal sweepings - The com bined " C h e v ro le t *sw eepings" and "G e n eral sweep in g s " . The f lo o r sw eepings w ere t r e a t e d i n the fo llo w in g way; . 1. C a re fu lly weighed. 2. Screened through an 8-mesh siev e in ord er to sep arate such m a te ria ls as sm all s to n e s , sc ra p s o f p a p e r, c l o th , b u rn t m atches, and such th in g s as could c o n ta in ho le a d . ; > \ ' ` ' f \ ' 3- 3 . Each p o rtio n of th e screened sweepings weighed se p a ra te ly . 4 . S creen ed sw eepings c a r e f u l l y exam ined f o r le a d by two a n a l y s t s whose r e s u lts agreed w ith in the lim it of e r r o r . Tabulation of R esults The d a ta o b tain ed a re ta b u la te d in the ta b le in clu d ed h erew ith . TAB! E "'eight of to t a l sweepings 9300 grams w eight of t o t a l screened sw eepings - - - - - - - 8000 grams " eight of sc re e n "C h ev ro let sw eepings" - - - - - - 255 grams h e ig h t of screened "G eneral sw/eepings" - - - - - - 7745 grams h e ig h t of lead in screened "G eneral sweepings" - - - - 2.40 grams P ercent of lead in screened "G eneral sweepings" - - - h e ig h t of lead in screened "C hevrolet sweepings" - - - .031 A 10.3 grams P ercent of lead in screened "C hevrolet sweepings" - - - 4.05 grams h e ig h t o f lead in to t a l sweepings - - - - - - 12.7 grams Percent of lead in screened t o t a l sweepings - - - - - .159 ^7 7^ P ercen t of le a d i n t o t a l sw/eepings - - - - .1 3 7 P< G allons of "E thyl Gas" burned in C hevrolet - - - - - 103.5 h e ig h t of lead in "E thyl Gas" burned i n C hevrolet -- -- - 322 grams P ercent of lead burned in C hevrolet found in to ta l sv/eepings- 3 .9 5 /% As estim ated from the d a ily record th e re w ere 442 car entrance and 426 c a r e x i t s d u rin g th e p e r io d o f the t e s t . Ko d o u b t some e n tr a n c e s and e x i t s escaped re c o rd . S ince th e th re e company tru c k s and one s e rv ic e c a r w ere n o t re corded, th e t o t a l number of c a rs e n te rin g the leav in g th e garage must have been a t le a s t double the fig u re s given above. 4 D iscussion of R esults During the t e s t p e rio d the w eather was g e n e ra lly good, w ith very l i t t l e r a i n , end th e c a r s came i n from a p av ed s t r e e t . So a minimum amount o f ro ad d i r t was c a r r ie d in to th e g a ra g e , a th in g w hich made th e p e rc e n ta g e of le a d i n th e sw eepings a t a maximum. - Talcing 6 m illig r a m s o f le a d p e r d ay a s th e to x i c d o se , th e fo llo w in g ob s e r v a ti o n s may b e made. On th e a ssu m p tio n t h a t th e g a ra g e em ployees ab so rb e d th e le ad from the g e n e ra l sweepings o n ly , th e y v/ould have to e x tra c t th e le ad from 697 grams o f d i r t in th e t h i r t y days in o rd e r to be in d an g er o f le a d p o is o n in g . I f t h e r e w ere 13 men i n th e g a ra g e th e y w ould have t o a b s o rb a l l th e le a d from th e gerw ral sweepings b efo re th e y would be in danger. That i s , i f in o rd er to absorb the le ad they b re a th e d in the flo o r d u st th ey would keep th e flo o r clean w ith sw eeping'. I f th e C h e v ro le t sw eepings a l s o be in c lu d e d 70 men w ould keep th e f l o o r c le a n i n th e same w ay. 00177.29