Losses of Cigarette Smoke Particles in Oral Cavities

Transcription

1 Le f Cgarette Smke Partcle n Oral Cavte O. Prce, B. Agharan, J. Schreter, C. U. Yurter, C. Dcken, and J. McAughey Aled eearch Acate, alegh, NC, USA Brth Amercan Tbacc, G&D BScence Dmetry, Suthamtn, UK

2 Fundng Acknwledgment Fundng fr the tudy wa rvded by Brth Amercan Tbacc.

3 Mtvatn Cgarette mke qute dfferent frm envrnmental PM: Hgh cncentratn f artcle Mxture f var and artcle Hygrcc Mult-cmnent (> 000 cnttuent) Frehly-generated, undergng rad change Unque breathng maneuver Detn redcted by lung detn mdel much lwer than meaured lung detn. Objectve t buld a new mdel that nclude cgarette artcleecfc rerte and mechanm f detn n bth the muth and lung.

4 Smkng Maneuver Drawng n the cgarette flter t generate a ~50 ml uff f mke that fll the ral cavty. Hldng the uff n the muth fr -3 ecnd. Inhalatn f dlutn ar t delver the cgarette mke uff t the lung. Exhalatn eeat Vare between and wthn ndvdual.

5 Mechanm Affectng Partcle Detn Cllgatve effect Hydrdynamc nteractn f artcle wth ther artcle and ar flw (clud effect). Nn-cllgatve effect Cagulatn Exchange f water var and ther cnttuent between the artcle and urrundng ar.

6 Cllgatve Effect Far Aart Lely Packed Clely Packed Clud effect: Partcle behave a a ngle bdy f dtnct denty and vcty. Partcle exerence a reduced hydrdynamc drag frce. Le retance.

7 Nn-Cllgatve Effect Hygrcc Grwth The humd envrnment f the reratry tract allw cndenatn f water mlecule nt the urface f cgarette mke artcle. ate f grwth deend n the ze f the artcle and the amunt f water reent n the envrnment. Phae Change Evaratn r cndenatn f vlatle CSP cmnent (nctne). ate f ze decreae deend n the ze f the artcle and the amunt f nctne reent n the envrnment. Cagulatn Deend n artcle cncentratn. Increae the ze f ndvdual artcle, but decreae artcle cncentratn.

8 Cmnent f Cgarette Smke Partcle Water Nctne Sem-vlatle Inluble Gven fr each cmnent: - Gram mlecular weght - Ma denty - Intal ma fractn Calculate at each tme te: - Cmnent ma fractn - Sze change

9 Cmnent Change Mdel Predctn Cmnent Intal Ma Fractn Water 0.08 Nctne Inluble Sem- Vlatle 0.34

10 Predctn baed n - hygrcc grwth - hae change - cagulatn Partcle Sze Change

11 Puff Smulatn

12 Hythetcal Puff Drawng Scenar Prr t uff, ral cavty cled. Puff f mke enter the ral cavty a a clumn f mke travelng a a free-hear flw. Imact n the back f the muth and dere nt the ral cavty t eventually fll the entre muth. N mxng f the uff wth the urrundng ar untl the uff ht the back f the muth. Partcle may det due t mactn wth the back f the muth r dffun a the mke dere. Addtnal detn may ccur by thermhre, Brwnan dffun, and gravtatnal ettlng.

13 Imactn Detn Fractn

14 Muth-Hld Scenar Puff dere nt the ral cavte and mxe wth the mall amunt f redual ar. Partcle cncentratn reduced due t cagulatn and mxng wth the redual ar n ral cavte. Partcle ze cntnue t change (ncreae) due t cagulatn, hygrcc grwth, and hae change. Partcle det manly by gravtatnal ettlng.

15 Detn Fractn by Thermhre Durng Muth-Hld 0.5 µm artcle

16 Detn Fractn by Gravtatnal Settlng Durng Muth-Hld

17 Clud Effect Mdel after flw thrugh ru meda (Brnkman, 947) Drag frce related t that f Stke drag n ngle hercal artcle makng u the clud: The ceffcent (F c ) related t artcle vlume fractn (cncentratn) and ermeablty. Stk c c D F F V d C d F F ) ( 3 ) ( 3 ) tanh( ) ( c d C F c d d 3 9 8

18 Detn n Oral Cavty Detn redctn ue cmbned mdel ncrratng cmnent change, artcle grwth, and clud effect.

19 Cnclun Tw rmary tental mechanm fr ral detn f CSP were nvetgated: Imactn durng the ntal uff Sedmentatn durng the muth-hld (Effect f thermhre and dffun al cndered) Lttle detn by mactn at the back f the muth redcted due t lack f artcle mmentum. Lttle detn by edmentatn durng muth-hld redcted due t lw ettlng velcte f mall mke artcle. Fr realtc CSP temerature, thermhre ha lttle effect n ral detn. Detn due t mactn and edmentatn enhanced when cllgatve effect (clud-lke rerte) are cndered.

20 Future Drectn Further nvetgate clud effect n artcle drag and ther detn mechanm. Cnduct CFD analy f cgarette uff n the ral cavty durng bth hae f ral detn. Extend the mdel t nclude cgarette artcle detn n the lung.

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23 Partcle Sze Change c hyg cag dt dd dt dd dt dd dt dd cag C dt d d dt dd 3 / 3 ) ( ) / /( ) ( ) ( t t e dt d e C w T d w M w n n n n w w n n w w w w hyg e m m F d M M m M m S Kn Kn Kn T d P M D dt dd T e M P m m F d M M m M m C Kn Kn Kn d D dt dd n T d n n n w w n n n n w w n n n c 4 3 ) (

24 Flw Feld Slutn Analytcal lutn va change f varable: u(r, ) a r '( ) ( ) a ( ) a z ''' '' ' 0 0 : 0 : : 0 ' 0 '

25 Flw Feld Durng Puff uctn Shear-free flw undeterred untl reachng near the back wall. Flw feld fund frm the lutn f ma and mmentum balance equatn: 0 z r u r u z r r r z P z r u z u r u r u r r u r P z u r u u (r,z) u(r, z) r z

26 Partcle Tranrt Durng Puff Suctn Effect f dffun n artcle trajectry: r z Frce actng un artcle: drag, thermhre, and gravty dv CSP m FD Fth Fg dt F D 3 d CSP V VCSP 9 d CSPHT Fth gt Fg mg net r z net t D' D H 6 d CSP 3 4e CSP t D' e CSP D' t k a 4.4 k CSP d CSP k a 8.8 k d CSP

27 Detn Fractn Durng Puff Suctn ral A CSP Flter end ectn A CSP / Prtn mactng n the late L Imactn late (back f muth)

28 artcle dameter: 0.5 µm Puff vlume: 50 ml Oral cavte ntal vlume: 50 ml Suctn tme: ecnd Partcle Trajectry

29 Detn Durng Muth-Hld Wrt cae cenar: Aume the blu frm near the wall unfrmly. Thermhre Gravtatnal Settlng Start f muth hld Tme t

30 Detn Fractn Durng Muth Hld 3 ral g S 3 ral th TD Tt H C 3 D t V V t n V t V t ) ( V t 0 V t V ) ( n n V t n V t V t ) ( V t V n n V t n V t V t ) ( Thermhre Gravtatnal Settlng V t V V t n V t V t ) (

31 Detn Fractn by Thermhre Durng Muth-Hld

32 Detn Fractn by Thermhre Durng Muth-Hld -ecnd muth hld

33 Clud effect n Partcle Detn Inertal mactn Stk F Gravtatnal ettlng V Brwnan dffun F c c 3 3 ( ( a a ) d 36 ) d 8 gc UC S ( d ( d ) ) D KTC ( d ) 3 d F c