Document G68XLK3ja4G9jeadDdB3ZYw2x

FILE NAME: Kent (KNT) DATE: 1954 Nov DOC#: KNT030 DOCUMENT DESCRIPTION: Unpublished External Report - Physical Properties of Cigarette Smoke A r.'TF 'lAP.CH r " :z k z :< " : of I l l i n o i s I n s titu te o f Technology Technol-r; Center Chicago 1 S I llin o is ArF T 'o ie c t ivo. C F3 -HYSICAL ?F.r:rl c T liS nF CIGAFTTZ S n K Summary R e o o rt, Lov e rb e r lFfli for Lori H a r d Company 111 F i r s t S tre e t J e rs e y C ity 2, Lew Jerse; Submitted by: 1. Langer r.sso ciate Chemical Engineer ARF-0127 96723989 PHYSICAL PROPERTIES OF CIGARETTE SMOKE PART I t GENERAL DISCUSSION OF RESULTS This p ro je c t, in itia te d in June 19539 has as i t s prim ary objective th e s tu d y o f th e p h y s ic a l p r o p e r tie s o f smoke from Old Gold and Kent c ig a r e t t e s . The p r o p e r tie s of th e smoke p a r t i c l e s o f p a r t i c u l a r i n t e r e s t a re siz e d i s t r i b u t i o n , c o n c e n tr a tio n , p h y s ic a l s t a t e , and b e h a v io r on f i l t r a t i o n . Answers to th ese qu estio n s w ill not only provide inform ation of general funda m ental in te r e s t but w ill a ls o y ie ld data to help in the system atic development of improved smoking p ro d u c ts. For in s ta n c e , p a r tic le s iz e d is tr ib u tio n and concentration are very im portant in th e development of f i l t e r - t i p c ig a re tte s . The p h y s ic a l p r o p e r tie s of smoke p a r t i c l e s a re c lo s e ly r e la te d to c o lo r and appearance of smoke, i t s t a s t e , and the degree of i t s re te n tio n by the body. Although th e r e i s r e l a t i v e l y l i t t l e in fo rm a tio n on i t s p h y s ic a l p r o p e r tie s the chem ical n a tu re o f c i g a r e t t e smoke has been s tu d ie d e x te n s iv e ly . An i n v e s ti g a ti o n o f t h i s `f i e l d ap p ears to be p a r t i c u l a r l y prem ising f o r new and use fu l inform ation. Over th e p a s t y e a r and a h a l f much has been accom plished in answer ing th e s e b a s ic q u e s tio n s . I t i s now p o s s ib le t o c h a r a c te r iz e f a i r l y c lo s e ly the p h y s ic a l n a tu re o f th e smoke as i t le a v e s th e c i g a r e t t e . The smoke con s i s t s o f l i q u i d d r o p le ts c o n ta in in g many extrem ely sm all s o l i d p a r t i c l e s . The d r o p le ts a re q u ite s ta b le and a re e s s e n t i a l l y of an o i ly n a tu r e . The smoke i t s e l f behaves l i k e a c o n tin u o u s f l u i d r a t h e r th an an a g g re g a te of p a r t ic u la te s in an enclosed a i r space, showing a strong tendency to hang to g e th e r, and to s e t t l e ra p id ly through q u ie t a i r . M icroscopic and photom icrographic exam inations of th e fre s h ly formed smoke show t h a t most of th e p a r t i c l e s a re l e s s than 1 m icron in d ia m e te r. .OMr.a s t i f jf . . - . O ' v - n ; * i t 'j t e o e : c - o i : 5 i 96723990 - 1 - ARF-0128 c u t down. This seem ingly high lo s s of smoke ag re e s w e ll w ith o th e r s tu d ie s on the lo ss of aero so ls in the lungs. In v estig ato rs a lso dem onstrate th a t rete n tio n i s reduced m arkedly as the p a r tic le s become sm aller than 0 .5 m icron. This p o in ts out the im portance of having sound fundamental data to understand adequately the behavior of c ig a rette snoke. The i n t e r e s t i n g answ ers obtained on th e s u b je c t o f the q u a n tity o f in h a le d smoke r e ta in e d by th e body brought up a problem of immediate p r a c t ic a l u s e , namely, i f th e s iz e o f th e smoke p a r t i c l e s can be red u c e d , would the r e te n tio n be l e s s a t th e same tim e. Figure 11 shows t h a t i f the smoke p a r t i c l e s could be reduced by s e v e r a l te n th s of a m icron, smoke r e te n tio n may be c u t con s id e r a b ly . Also th is smoke should be r a t h e r m ild and voluminous} th is may be accomplished by sp e c ia l se le c tio n of tobaccos, ad d itio n of in e r t f i l l e r s to c o n tr o l th e b u rn in g te m p e ra tu re , o r chem ical e x tr a c t i o n . In s tu d ie s a t Duke U n iv e rs ity sponsored by th e Damon Runyon Fund e x tr a c t i o n w ith a lc o h o l has been shown to reduce p a r tic le s iz e . Equipment to study the e ffe c tiv e n e s s of such m odification is already av ailab le. The chem ical com position of c ig a r e t t e smoke may v ary w ith the p a r t i c l e s i z e , th e m o istu re c o n te n t of th e to b ac c o , th e number o f th e p u f f , and th e type of c i g a r e t t e , i e , p la in or f i l t e r t i p . In fo rm a tio n on th e s e v a r i a b le s i s o f g r e a t i n t e r e s t , s in c e th e p h y s io lo g ic a l e f f e c t s of c ig a r e t t e smoke a re due to i t s chem ical com p o sitio n . The p r e s e n t equipm ent can r e a d ily pro v id e sam ples f o r q u a n tita tiv e a n a ly s i s , and i t may be p o s s ib le to c a rry out q u a l i t a t i v e chem ical t e s t s on in d iv id u a l p a r t i c l e s by means o f chem ical microscopy. In a l l t h i s work th e c ig a r e t t e s were smoked a t s ta n d a rd c o n d itio n s , b u t in a c tu a l use th e smoking c o n d itio n s may b e 'f a r frcm s ta n d a r d . Changing a a m o ,, a 1 1 ; ; m u f ->.* d a t n o f > t n s i n s ' i t u ' ; o f ' s c > . r % t 96723992 - 3- ARF-0130 the smoking r a t e and m o istu re c o n te n t may change p a r t i c l e s iz e and c o n c e n tra tio n c o n s id e ra b ly and th e re i s some evidence t h a t t h i s i s th e c a s e . There f o r e , some s tu d y of th ese v a r ia b le s would make th e p re s e n t d a ta much more com p lete and in c lu s iv e . A g ra p h ic summary of the most im p o rta n t r e s u l t s and of some eq u ip ment i s shown on the follow ing pages. These r e s u l ts and the techniques used in th is program are discussed in d e ta il in the second p a rt of th is re p o rt. 96723993 o t u i n cm s n s t i t j ~ ' i c wn o ; 5 f -u - ARF-0131 P ig . 1 OLD GOLD PUFF 2 ,5 u. 96723994 F ig . 2 KENT PUFF 2 $ These photom icrographs a re tak e n f r c r smcsce sam oles tak e n under i d e n t i c a l c o n d itio n s . They snow the lower c o n c e n tra tio n and tn e somewhat sm aller p a r tic le s iz e o f the Kent smoke. - 5 - ARF-0132 F ig . It KENT PUFF 11 S/K ^ The photom icrographs were tak e n under th e same c o n d itio n s a s the p rec e d in g s e t and show the in c re a s e in c o n c e n tra tio n and p a r tic le s i 2e as th e c ig a r e tte i s smoked. S66Z196 - 6 - ARF-0133 This apparatus combines an autom atic c ig a r e tte smoker w ith equipm ent f o r a c c u r a te ly d i l u t i n g th e smoke w ith c le a n a i r and th en o b ta in in g s p e c i a l samples o f smoke p a r t i c l e s f o r d e ta ile d stu d y and m easurem ent. The large f la s k , (low er c e n te r), contains d ilu te d smoke. A h o r iz o n ta l beam of l i g h t through t h i s f l a s k i n d ic a te s th e approxim ate smoke c o n c e n tra tio n . A moving s lid e sampler is above the fla s k . F ig . 5 AUTOMATIC SMOKING MACHINE AND SMOKE-SAMPLING EQUIPMENT 96723996 %- &' - 7 - ARF-0134 Frequency > 662ZZ96 33 n o CO cn Fi;:- 6 P a r t i c l e D iam eter Rane i n M icrons (1 /1 0 ,0 0 0 cm) AVERAGE STZ DISTRIBUITO"' OF KENT AMP CLP GOTH orOARSTTS STOICS PARTICLES Concentration, M illion P articles per cubic centimeter P i g . 7 SMOKE CONCENTRATION DATA A ft M O U n F igure 7 i l l u s t r a t e s th e main d if f e r e n c e betw een th e Kent and Old Oold smoke, nam ely, th e much low er p a r t i c l e c o n c e n tra tio n o f th e K ent.- I t should be noted th a t th e d ifferen ce in creases as the c ig a re tte is smoked. In o th er words th e tobacco a c ts as f a ir ly e ffe c tiv e f i l t e r but ^ lo se s i t s e ffe c tiv e n e ss as the c ig a re tte becomes s h o rte r. "<! NO CM VO VO CO i!Ese*ncu f o u n d a t i o n or u i n O is in s t it u t e or t e c h n o l o g y ARF-0136 Volume o f Smoke P a r t i c l e s p e r F u f f , cc 0.008 0.006 O.OOli 0.002 12 3 H 56 78 9 10 11 P u ff Number F ig . 8 VOWS OCCUPIED PV P*0KR PARTICLES The smoke p a r t i c l e s i n a p u ff from a Kent c ig a r e t t e occupy h a l f th e volume o f th e smoke p a r t i c l e s in a p u ff f r a n an Old Gold 9672Z999 - 10 - ARF-0137 6.0 W eight o f Smoke p e r P u f f, m illig ra m s > DO TJ 6 CO 00 OOi3PZZ96 P u ff Nuabr P ig - 9 WEIGHT OP EXHALED AND IWHALED StfOXE to igh t o f Sook Retained bjr Body, milligram F a f f Number 96724001 F ig . 10 WEIGHT OF SMOKE RETAINED AFTERINHAICTOF F igure 10 i l l u s t r a t e s th e d iffe re n c e between Kent end Old Gold c ig a r e t t e s , lh e w e ig h t o f smoke l o s t to th e body from a Kant i s v ery much 1carer, l a r g e ly because th e smoke in a p u f f from a Kent w eighs l e s s . A f i v O v / K G C S i A f t C W f G `j N 0 A T I o N O F f L l i N O i S : N $ T! T 1/ T 5 O* T C w n O l O G y - 12 - ARF-0139 96724002 ARMOUR RtStARCM F ig . 11 RETENTION OP PARTICLES BT LOWER LONGS FOUNDATION Motet This curve le fo r m ate ria l of u n it d e n s ity . For c i g a r e t t e smoke the curve should be sh ifte d s lig h tly to the l e f t . Of I L L I N O I S I NST I TUT S OF T E C H N O L O S T - 13 - ARF-0140 12 ''T T , AHHJN'E ARF-0141 96724003 Viat e r Overflow 2 Constanthead Viate r Supply I K 9 F lo a t Burette Solenoid Valve Operated by Smoker Smoking Machine Pump Membrane F ilt e r on which Smote i s d ep osited and weighed Exhaled Smoke or C ig a rette Smoke Supplied a t Standard Rate to Human Smoker S u ction from Smoking Vachine When Sampling Inhaled Smoke Weight Sampler A R F-0 1 4 2 frOOi'Z196 Fig* 13 EQUIPMENT FOR OBTAINING WEIGHT SAMPLES OF EXHALED SMOKE F ig Hi DUST COLLECTED FROM 1500 cc OF AIR F ig . IS DUST COLLECTED FROM 1500 cc OF AIR iO/i FILTERED THROUGH AN OLD GOLD ' ' Fig 16 DUST COLLECTED FROVf 15DC cc OF AIR FILTERED THROUGH A KEUT WITH A FEW ASBESTOS FIBERS FROM THE FILTER - 16 - ARF-0143 96724005 i 7 / *' / P m \ // / V V *. - - F ig . 17 FIBERS FROM A KENT FILTER THAT HAS NOT BEEN USED 96724006 F ig . 18 A FIBER COATED WITH SMOKE SUBSTANCE FROM A KENT FILTER USED ^CR ONE PUFF A W Te " mN - 17 - ARF-0144 PART 2: TECHNICAL DISCUSSION This p a r t of th e r e p o r t g iv es some of th e te c h n ic a l d e t a i l s of the re se a rc h on th e p h y sic a l p ro p e rtie s of c ig a r e tte smoke. F i r s t , an a d a p ta tio n o f the s ta n d a rd smoking machine was b u i l t t h a t placed s p e c ia l emphasis on han d lin g th e smoke so t h a t i t i s n o t a lt e r e d a f t e r i t le a v e s th e c i g a r e t t e , and tec h n iq u e s were d ev ised to sample and analyze t h i s smoke. The second phase involved the ro u tin e a p p lic a tio n of the equipment and techniques to many Old Gold and Kent c ig a r e t t e s to o b ta in firm d a ta on th e s iz e and concen t r a t i o n o f th e smoke p a r t i c l e s . This in fo rm a tio n was then used in a s tu d y of ex haled smoke to in v e s tig a te the r e t e n ti o n of th e smoke by th e lu n g s . The v a rio u s a s p e c ts of t h i s p r o je c t w i l l be d isc u s s e d in th e fo llo w ing sequence* equipment, a n a ly tic a l procedures, and d iscu ssio n of re s u lts . I . EQUIPMENT A. Smoking Machine An autom atic smoking machine was b u i l t , as p ic tu re d in F ig . 5 and sk etch ed i n f i g . 12, based on the s ta n d a rd c o n d itio n s of a 3i>-cc p u ff in 2 sec a t 1-min i n t e r v a l s . O ther re q u ire m e n ts were t h a t the smoke should n o t be a lte re d a f t e r i t lea v e s the c ig a r e tte and th a t i t should be p o ssib le to sample th e smoke from e v e ry p u f f . To meet th e f i r s t c o n d itio n , the smoke i s immed i a t e ly d ilu te d by the volume of a i r in the 5000-cc f la s k to prevent agglomer a t i o n . A q u ick b l a s t of a i r b reaks up the smoke t h a t e n te r s th e f la s k i n the form o f a s o lid stream t h a t does n o t mix w ith th e surro u n d in g a i r . In order to sample e v e ry p u f f , th e machine has to be f u l l y a u to m a tic . This i s accom p lish e d w ith a 1-rpm motor th a t a c tu a te s a s e rie s of m icrosw itches through a s e t o f notched m e ta l d is k s , shown a t th e low er r i g h t o f F ig . f>. The sw itches o p erate the solenoid v a lv e s th a t c o n tro l the flow system in the machine. ASMOU3 F O U N D A T I O N Of I L L I N O I S I NSTITUTE Of T E C H N O L O G Y 00PZ196 - 13 - A R F -0 1 4 5 S u ffic ie n t suction to p u ll 35 cc o f a ir through the c ig a re tte is a p p lie d when w ater is allow ed to run out of the su c tio n b u re tte by opening Valve 5 (P ig - 1 2 ). At the same tim e Valve 1 opens f o r 2 s e c j t h i s i s a s p e c ia l v alv e th a t gives a d i r e c t passage fo r th e smoke. There i s a 20-sec in te rv a l fo r sampling a f te r a p u ff, and then the larg e fla s k is purged of smoke w ith compressed a i r e n te r in g through Valve y and 2 and i s exhausted through the p ressu re re le a s e tu b e , which a ls o se rv e s as a manometer to in d i cate the resistan ce of the c ig a re tte . To supply s ta n d a rd amounts of smoke to human smokers f a r th e stu d y o f exhaled smoke the m anually o p e ra ted m achine- F ig . 13, i s u sed . When the solenoid valve i s sw itched on, 35 cc of w ater run o u t o f the b u re tte and d is place a 35 cc of a i r through th e c ig a r e tte from the a i r space follow ing the so le n o id v a lv e . The burning end o f th e c i g a r e t t e i s held i n th e shroud by th e smoker j u s t b e fo re a p u ff i s due. The smoker then re c e iv e s the smoke and in h a le s. B. Moving S lid e Im pinger A number o f sam plers were te s te d to c o ll e c t the smoke f o r a n a ly s is . Of th e s e , a moving s l i d e im pinger proved t o be m ost s u c c e s s fu l f o r ro u tin e d e term in atio n s o f c o n c e n tra tio n and s iz e d is tr ib u tio n , w ig h t samples o f the smoke were c o n v e n ie n tly c o lle c te d by com bining a membrane f i l t e r w ith an im p in g e r. The o th e r sam plers te s te d w ere a therm al p r e c i p i t a t o r , an e l e c t r o s t a t i c p r e c ip ita to r , and a s e tt li n g chamber. A moving s l i d e im p in g er, shown in the upper r i g h t of F ig . 5 and 12, c o n sists of a microscope s lid e th a t can be pulled a t co n stan t speed p a st a j e t a t r i g h t a n g le s to the s l i d e . The j e t d i r e c t s the smoke onto the s li d e a t c lo s e t o so n ic v e lo c i ty . The smoke p a r t i c l e s impinge on th e s l i d e , sin c e ARMOUO RESEARCH FO UN DA TIO N OF ILLINOIS INSTITUTE Of TECHNOLOGY" 96724008 - 19 - ARF-0146 th e ir in e r tia is too high to follow the sudden change in d ire c tio n of the gas flow . I f a s ta tio n a ry s lid e were used, the p a r tic le s would p ile up too f a s t and o v e rla p . Even i n t h i s case th e smoke has t o be d ilu te d a second tin e a f t e r le a v in g the 5000-cc f la s k by a f a c to r of 15 to p re v e n t ag g lo m eratio n . The d i l u t e r f o r t h is purpose surm ounts the f l a s k , as seen in P ig . 5 and 12. C. Weight Sampler I n o rd er to c o l l e c t a l l the smoke i n a p u ff and w eigh i t , th e sam p l e r shown a t th e r i g h t o f P ig . 13 has proven t o be very c o n v e n ie n t. Exhaled smoke i s sim ply blown i n t o i t w h ile s u c tio n i s a p p lie d to th e f i l t e r . For sam ples of in h a le d smoke th e c i g a r e t t e i s a tta c h e d t o th e m outhpiece, and s u c tio n i s a p p lie d to th e chamber w ith th e smoking m achine. Then the sam pling procedure i s s t a r t e d . The smoke p a sse s through the j e t a t a f a i r l y high v e lo c ity ; moat of i t im pinges on a membrane f i l t e r ; and th e r e s t i s in te r c e p te d by th e f i l t e r , w hich can th e n be w eighed. A membrane f i l t e r (S c h le ic h e r and Schuell) is a nonfibrous sm ooth-surfaced f i l t e r w ith uniform tu b u lar holes. This arrangem ent was used because of i t s s im p lic ity and a v a i l a b i l i t y . The smoke co u ld a ls o be c o lle c te d i n a s m a ll cup fa c in g th e j e t . D. Thermal P re c ip ita to r The th erm al p r e c i p i t a t o r i s r e p u te d ly 100$ e f f i c i e n t f o r p a r t i c l e s below 5 m icrons. I t c o lle c ts ae ro so l p a rtic le s by therm al re p u lsio n from a hot w ire th a t faces a cold microscope cover s lip which serves as the c o lle c to r. This in stru m en t re q u ire s a good d e a l o f s k i l l and tim e to o p e ra te , but i t i s u s e f u l to check th e e f f i c i e n c y of th e im p in g er. The in stru m e n t can be seen a t th e low er l e f t of F ig . 5 and 12 connected t o a 1000-cc f l a s k , w hich in tu rn i s connected to th e 5000-cc f l a s k . The s m a lle r f la s k s e rv e s to d ilu te a 30-cc or so smoke sample p u lle d from the 5000-cc chamber w ith th e s y rin g e . a am o u a h e se a b c m c o u n o a Tion or n i ' N O i S in s t it u t e of t e c w n o l O G t 96724009 - 20 - ARF-0147 Hie smoke i s mixed w ith the paddlej th e n an a s p ir a to r connected to th e therm al p r e c ip ita to r draws aero so l through i t a t 6 cc/min fo r about 3 min. E. E le c tro s ta tic P re c ip ita to r E le c tr o s ta tic p r e c ip ita to r s a re a ls o n early 1001 e f f i c i e n t. With t h i s in stru m e n t a l l th e smoke p a r t i c l e s a re c o lle c te d on th e w a lls of a tube connected to a high voltage source. A c e n tra l w ire in the tube serves as the second e le c tr o d e and r e p e ls th e p a r t i c l e s onto th e w a l l. The tube i s la rg e enough t o accommodate a p u ff o f smoke w ith s u f f i c i e n t d i l u t i o n to p re v e n t over la p p in g o f th e p a r t i c l e s on the w a ll; about U000 cm^ o f w a ll a re a a re n eces s a r y . The tu b e , in t h i s case g la s s covered w ith aluminum f o i l on th e o u ts id e , i s f i l l e d ev en ly w ith smoke, and th en th e e l e c t r i c i t y i s tu rn e d on to approx im a te ly 10,000 v . Hie p a r t i c l e s a re c o lle c te d on very sm a ll p ie c e s of g la s s r e s tin g on th e w a ll. These p iec e s a re coated w ith s ilic o n e to p rev en t sp read ing of th e smoke p a r t i c l e s . However, th ey a re coated only on th e s id e away from th e tu b e w a ll; otherw ise no p a r t i c l e s a re c o lle c te d . F. A erosol S e ttlin g Chamber A s e t t l i n g chamber was s e t up to study the g ra v ity s e t t l i n g o f the smoke p a r t i c l e s . For t h i s purpose a g la s s c y lin d e r f i l l e d w ith smoke i s sub merged in d i s t i l l e d w a te r to keep th e smoke a t a c o n s ta n t te m p e ra tu re . The c y lin d e r i s illu m in a te d w ith a s tro n g l i g h t beam t o fo llo w the s c a t t e r in g of lig h t from the p a rtic le s as an in d ic a tio n of the s e ttlin g process. I I . ANALYTICAL PROCEDURES A. M icroscopy A ll th e smoke sam ples, e x c e p t f o r th e l i g h t - s c a t t e r i n g and w eig h t sam ples, have to be analyzed w ith a m icroscope. Both e le c tr o n and o p tic a l m icroscopy have been i n v e s tig a te d . The form er has n o t shown too much prem ise A R MO UR R E S E A R C H C O U N O a TION Ot I L L I N O I S I NS T I T U T E O E T E C U N O l OG* 96724010 - 21 - ARF-0148 fo r ro u tin e work. D iffic u ltie s are encountered in preparing a proper mount because o f the v o l a t i l i t y o f th e smoke under a high vacuum and because of i t s chem ical co m p o sitio n . Both f a c t o r s make i t d i f f i c u l t to p rep a re r e p l i c a s . Of th e o p tic a l m icroscope m ethods, d a r k - f ie ld illu m in a tio n gave the b e s t r e s u l t s . B r ig h t- f ie ld illu m in a tio n could n o t be used d i r e c t l y because o f th e v e ry low c o n tr a s t of th e smoke p a r t i c l e s mounted in a i r and th e la c k of a p ro p er mounting medium. C oating th e s l i d e s w ith a dye t h a t would be d is s o lv e d by th e smoke was n o t f e a s ib le because the dye c r y s t a l s could n o t be produced sm all enough w ithout elab o rate equipm ent. Coating the p a rtic le s with io d in e c r y s ta ls from io d in e fumes gave good c o n tr a s t, b u t th e io d in e a lso made a l l th e subm icroscopic rough sp o ts on th e g la ss v i s i b l e . Phase m icroscopy gave n egative r e s u l ts in a few i n i t i a l t e s t s , p o s s ib ly owing to th e la c k o f a s u ita b le mounting medium. Since the d a rk f i e l d method gave good r e s u l t s , no f u rth e r work was done in th is f i e l d , and no d e f i n i t e sta te m e n t can be made on th e u s e fu ln e s s o f phase m icroscopy. A Spencer 0.S5 N.A. b i s p h e r ic a l, o i le d , d a r k - f ie ld condenser w ith a Z e iss N e o flu a r 0 .7 5 N.A. hOx o b je c tiv e proved to be th e b e s t o p t ic a l combina t i o n . The r e s o lv in g power of the equipm ent i s such t h a t a L e itz P e rip la n 25x eyepiece i s j u s t i f i e d f o r th e photom icrographic work. The a n t i r e f l e c t i o n c o a tin g f o r red u c in g g la r e on th e o b je c tiv e may account f o r i t s s u p e rio r p e r formance. G lare i s a problem sin ce the condenser design s p e c ifie s a liq u id m ounting medium. To compensate f o r the a i r space between th e cover s l i p and microscope s lid e in which th e p a rtic le s are lo c a te d , the eyepiece d istan ce had t o be in c re a s e d from 160 to 175mm. Kodak Super XX film i s used f o r photo m icrography w ith l /2 - to 3-min exposures. 96724011 ARMOUR RESEARCH C O UNDAT I ON Of I U I N O I S I NSTI TUT{ OP T ECHNOLOGY - 22 ARF-0149 The m icroscope s l i d e s have to be o f the p roper th ic k n e s s and o f the h ig h e s t q u a li ty . They must be cleaned th o ro u g h ly and coated w ith s ilic o n e to keep th e sp re a d in g of th e p a r t i c l e s to a minimum. - y'- i g h t Sampling The a n a ly t ic a l procedure f o r w eighing samples of c ig a r e t t e smoke i s r a t h e r sim p le . The f i l t e r s a re allow ed to c o n d itio n in the room atm osphere and a re weighed j u s t b e fo re and a f t e r sam pling. The passage o f a i r alone th rough the f i l t e r does n o t change i t s - 's i g h t . The co a rse type o f membrane f i l t e r c o l l e c t s a l l of th e smoke e f f e c t i v e l y . I I I . DISCUSSION OF RESULTS One of th e f i r s t o b je c tiv e s of t h i s re s e a rc h i s to e s ta b l is h the p a r t i c l e s iz e d i s t r i b u t i o n and c o n c e n tra tio n o f th e smoke from Old Gold and Kent c i g a r e t t e s . This was accom plished w ith th e moving s lid e im pinger. Then, in fo rm a tio n on th e amount of smoke r e t a in e d a f t e r in h a lin g i n to the lungs ap peared t o be h ig h ly d e s i r a b l e . To assem ble th e l a t t e r in fo rm a tio n , w eight sam pling o f th e smoke proved to be th e m ost d i r e c t m ethod, as every second ex haled b r e a th could be sam pled. An o v e r - a ll summary of the r e s u l t s appears in Table 1. Table 1 C igarette Old Gold Kent Average P article S iz e , M icrons 0.6 0.5 SUMMARY OF RESULTS Average Con c e n tra tio n , P artieles/ce itUO m illio n Average Weight of Smoke p er P u f f , mg 3-8 280 m illio n 2.1 Average Weight of Smoke R etained a fte r Inhaling in to th e Lungs, mg 3-3 1 .6 96724012 ARMOUR RESEARCH rOUNDATION O' ILLINOIS institute Of TECHNOLOGY - 23 - ARF-0150 The p a r t i c l e s iz e and c o n c e n tra tio n d a ta a re shown in more d e t a i l in P ig . 6 , 7, and 8. Figure 6 shows th e range in p a r t i c l e s iz e and p o in ts out t h a t Kent smoke c o n s is ts o f somewhat s m a lle r p a r t i c l e s . Figure 7 dem o n strates t h a t the s a l i e n t d if f e r e n c e between th e two c i g a r e t t e s i s th e v e ry much low er number o f p a r t i c l e s i n th e Kent smoke. The p h o to g rap h s, F ig . 1 -h , i l l u s t r a t e the d iffe re n c e s between th e two c i g a r e t t e s . Figure 8 g iv es th e volume of the smoke p a r t i c l e s in a p u f f . These d a ta can be c o n v erted to w e ig h t of smoke p e r p u f f to compare w ith th e w e ig h t samples from the membrane f i l t e r s . Figure 9 shows th e l a t t e r d a ta which p a r a l l e l th e c o n c e n tra tio n d a ta . The w eight o f smoke p e r p u ff from th e s iz e d i s t r i b u t i o n d a ta i s c a lc u la te d t o be higher} however, th is would be expected because the p a rtic le s are bound to spread frcm a tr u e s p h e r ic a l shape on th e s l i d e . The sp re a d in g f a c t o r ap p ears to be c lo s e t o 1 .2 . The d i f f i c u l t y in e s ta b l is h in g t h i s f a c to r p r e c is e ly i s the la c k o f d a ta on the d e n s ity of the c i g a r e t t e smoke in q u e s tio n . The r e s u l t s from th e stu d y on exhaled smoke show t h a t from 70% to 90% fcy w eig h t of the smoke i s l o s t when i t i s in h a le d in to the lu n g s. This i s based on the prem ise t h a t a l l th e smoke n o t r e ta in e d by th e lungs w i l l be e x p e lle d i n th e f i r s t e x h a la tio n a f t e r a p u f f . E xperim ental work has shown t h a t smoke i s ex h aled i n su b seq u en t b r e a t h s , b u t r e s u l t s t o d a te show t h i s amount to be n e g lig ib le . I f th e smoke i s tak e n in to th e mouth only, up to 20% by w eig h t may be r e t a in e d . The p a r t i c l e s exhaled from th e lungs a re sm a lle r than th e o r ig in a l. These p a r t i c l e s iz e d ata were obtained w ith the moving s li d e im pinger} the smoke was ex haled i n to the 5000-cc f la s k o f the smoking machine. F ig u re 9 d em o n strates th e h ig h r e t e n ti o n o f smoke in the lcsrer r e s p i r a t o r y system , w h ile F ig . 10 compares th e w e ig h t o f smoke re ta in e d from ARMOUR R E S C A R Cm F O U N D A T I O N Of ILLINOIS INSTITUTE OF T EC HN OL OG Y 96724013 -21- ARF-0151 Kent and Old Gold c i g a r e t t e s . These graphs shew t h a t th e r e t e n ti o n of Kent smoke i s about 10? l e s s th an t h s t of Old G olds. This may be due t o the s m a lle r s iz e o f the Kent p a r t i c l e s . Since th e re i s much l e s s smoke in a p u ff from a K ent, th e w eig h t picked up by the body i s much low er than t h a t from an Old G old. I t should be remembered t h a t th e se r e s u l t s a re from one male and one fem ale smoker. But th e r e s u l t s seem t o be a p p lic a b le in g e n e ra l, sin c e th ey a re i n good agreem ent w ith w hat i s known about th e r e t e n ti o n o f a e ro s o ls by th e lu n g s . F igure 11, which c l e a r l y i l l u s t r a t e s the Im portance o f p a r t i c le s iz e in th e s tu d y of c i g a r e t t e smoke, i s a p a r t o f a r e p o r t by W. B. K a rris (A.M.A. A rch. In d u s, ify-g. 8, U i5j 1953)- I n th e s e c tio n on equipm ent seme a u x ilia r y sam pling in stru m en ts were d is c u s s e d . The therm al p r e c i p i t a t o r was used to c a r r y out c o n c e n tra tio n and s iz e m easurem ents a t th e same tim e an im pinger sample was ta k e n . A suc c e s s f u l procedure has been worked o u t fo r t h i s work a f t e r some m o d ific a tio n of th e p r e c i p i t a t o r . The h e a t from th e h o t w ire of th e therm al p r e c i p it a to r has no n o tic e a b le e f f e c t on th e p a r t i c l e s . Both in stru m e n ts seem t o give the same r e s u l t s b u t a l a r g e r number of t e s t s need to be made f o r a p re c ise com parison. The e l e c t r o s t a t i c p r e c i p i t a t o r has a d e s ir a b le f e a tu re in t h a t the smoke can be sampled w ith o u t going through a v a lv e , a second d i l u t e r , and a high v e lo c ity j e t . On th e o th e r h and, i t i s not a p r a c t i c a l instrum ent, fo r ro u tin e work in th is case. A fter considerable e f f o r t the sampling teennique was worked o u t. Again g e n e ra l agreem ent was found w ith th e im pinger sam pler. Lack of time precluded any d e ta ile d comparison, though. The a e ro s o l s e t t l i n g chamber gave some q u a n tita tiv e r e s u l t s when smoke had s e t t l e d frera 5 to 30 m in. That i s , th e l i g h t beam e x h ib ite d c o lo re d A t) M O <' i) R E S E A R C H F O U N D A T I O N or I L L I N O I S I N S T I T U T E O f T C N O l O G t 96724014 - 25 - ARF-0152 bands in d icatin g the presence of predominant p a rtic le sizes a t various lev els in th e s e t t l i n g c y lin d e r. However, the s iz e d a ta showed th e presence of f a i r l y la rg e p a r tic le s in d ic a tin g th a t agglom eration was tak in g p la c e . D ilu t in g the smoke s u f f i c i e n t l y to p re v e n t t h i s makes v is u a l s tu d ie s d i f f i c u l t and, fu rth erm o re, w ith th e sm aller p a r tic le s the o p eratio n of the s e ttlin g chamber becomes very s e n s itiv e to minute tem perature flu c tu a tio n s . In the course of t h is in v e s tig a tio n a number of sh o rt-ran g e stu d ie s were c a r r ie d o u t; one stu d y concerned th e f i l t r a t i o n o f atm ospheric d u s t by u n l i t c i g a r e t t e s . On a p a r t i c l e co u n t b a s is b o th Kent and Old Gold c ig a r e t t e s removed ab o u t $0% of th e d u s t. However, on a w eig h t b a s is th e Kent i s very much more e f f e c t i v e a s shown in F ig . I k , 15 and 16 which dem onstrate th e f i l t r a t i o n of th e l a r g e r d u s t p a r t i c l e s t h a t make up most of the w e ig h t. Figure 17 sh o rs a few a s b e s to s f ib e r s p u lle d from th e f i l t e r by th e a i r stre a m . When th e e x tin g u is h e d c i g a r e t t e i s te s te d a f t e r one p u f f , h a rd ly any a s b e s to s fib e rs are found. Some work was done to fo llo w what happens to th e smoke p a r t i c l e s caught by the Kent f i l t e r . A f i l t e r was c a re fu lly opened above a microscope s l i d e so many of th e f ib e r s would s e t t l e on i t . Exam ination showed th a i n d iv id u a l smoke p a r t i c l e s a re r a t h e r lo o s e ly a tta c h e d to th e f i b e r s , which a re c o n s id e ra b ly s m a lle r i n d ia m e te r th an th e p a r t i c l e s . When enough p a r t i c l e s a re on a f i b e r , th ey c o a le s c e and c o a t the f i b e r . F ig u res 17 and 16 show the asb esto s f ib e r s b efo re and a f t e r the f i r s t p u ff of smoke. 96724015 ARMOUR RESEARCH FOUNDATION Of ILLINOIS INSTITUTE OF TECHNOLOGY - -26 - ARF-0153