|
/ aahk+n, Simmons, Sheriff, er 01.: r',u Jna and Annual Change in FN, O
<br />) 147
<br />l/
<br />r end/or emphysema. Although ryn Jim s of chrome bronchitis
<br />are believed to be related histopathologically to hypertrophy or
<br />marijuana smoke than they wccc amutomcd to which would
<br />submucosal bronchial mucous gland; AtteratiQm in ciliated bran-
<br />' chial epithelial cells, and hyperplasia of mucus
<br />not have progressed at the same rate with much more prolonged
<br />exposure in the face of emerging adaptive mechanisms.
<br />-secreting goblet
<br />cells (29), these symptoms of mucus hypersecretare not
<br />thought to be necessarily lini
<br />ked to the
<br />Conclusion,
<br />In nclusion, findings from the present long-term, follow-up
<br />study of heavy, habitual marijuana smokers argue
<br />progressive damage to
<br />and narrowing of peripheral airways that accompany the evolu-
<br />lion of smoking-related chronic obstructive airways disease (30),
<br />against the
<br />concept that continuing heavy use Of marijuana is a significant
<br />risk factor for the development of COPD. These negative find -
<br />ings,
<br />It is possible that the contrasting effects of marijuana and
<br />tobacco smoking in the present study on
<br />however, do not imply that regular marijuana smoking is
<br />free of harmful pulmonary effects. Habitual marijuana
<br />Progreasive changes in
<br />lung function might be due to the marked disparity in the quan-
<br />tity of the two substances that were smoked: an
<br />smok-
<br />ing is associated with a higher than expected prevalence of symp-
<br />toms of chronic bronchitis (15, 16), as well as a higher incidence
<br />average of 4.1
<br />joints/d in the marijuana -only smokers versus 27.5 cigarettes/d
<br />the Although the precise amount
<br />oracute bronchitis (15). Moreover, other evidence suggests that
<br />marijuana ouy be an important risk factor for the development
<br />M anatobacco-onlyskedsmokers. of
<br />marijuanasmoked cannot be accurately determined because of
<br />the uncertain reliability of self-reported usage
<br />of respiratory infection (9, 35), and possibly respiratory maljg-
<br />nancy (36). Further studies are required to document the
<br />and the common
<br />practice of sharing joints, it is highly likely that the amount of
<br />real re -
<br />spiratory risks of this commonly smoked substance.
<br />actual usage of marijuana was far less than that of tobacco, On
<br />the other hand, differences in fdlralion of smoke through the
<br />" b"ekd9"emV The authors thank Mr. Enoch tee for his technical asdstame
<br />and Mr, John Dennand for his assistance in tracking and I
<br />more densely packed tobacco cigarettes (in which cellulose filters
<br />°cab"9 Pa tQwnu.
<br />were generally incorporated) and the more loosely packed, filter -
<br />less marijuana joints, whlchareusuall sm ked
<br />length, approximately double the tar yield of themarmuajoint References
<br />ian
<br />(18), Moreover, differences in smoking topography (larger Cu. I. Johnnone, L. D., P. M. O'Malley, and J. G. Bachman. 1994. National
<br />mulative puff volumes and inhaled volumes of marijuana smoke survey results on drug use from The Monitoring the Future Study,
<br />and a d fourfold longer smoke retention time for marijuana than 1975-93, Volume I. Secondary School Students. Nations) Institute
<br />On for tobacco), added to the differences in smoke filtration, may PrlmtinggOffi see Waslhinnggton P1DC No,
<br />9°-Jao9. V.S. Governmem
<br />result in a fourfold greater retention of tar in the lungs of martin• 2. Johnstone, L. D., P. M. O%a&y, and J. G. Bachman. 1994. National
<br />ana smokers compared with smokers of a comparable quantity survey results on udy
<br />drug use from The Monitoring the Future St,
<br />orwhole tobacco (31). This amplification of the exposure of the 1975-93, Volume fl. CoOcge Students end Young Adults. National
<br />lungs to the smoke of marijuana narrows the gap between a ;a six. lustiluu on Drug Abuse, NIH Publication No.94-3810. U -S. Gores,
<br />fold greater quantity or reported u went Printing Office, Washington, DC.
<br />sage of to perhaps 3. Hoffmann, D., D. K. &unoemann, G. B. Gori, and E. L. Wynder.
<br />the
<br />only approximately twofold greater exposure of the lungs to x975. Qct the arcinogcnidty of maty' G.
<br />B. smoke. Ree. Adv. Wynder. the smoke from tobacco compared with marijuana. Thus, quart. them. 9:63-81.Ph
<br />titative differences alone may not entirely explain the disparity 4. N°`rotnY• M., F. Meru, D. Weider, M. Fetal, and T. Saeed. 1982. Fnc-
<br />in longitudinal rates of decline in lung function between the two donation and capillary gas chro
<br />ofsmokers. "utographk mass spectrometric char -
<br />[he
<br />twi?videncethatQualitativedifrerencesbetwm "t t'40"0fthttunalcvmponenuInnurijuanaandtobaccosmoke
<br />the two types Of smoke may be more important thanuantita- condensates. 1. CAromarogr. 238:141.150.
<br />live differences with res P q 5• Roy, P. E., F. Magnan -Lapointe, N. D. Huy, and M. Bourn. 1976.
<br />pect to the development of COPA de- Chronic Inhalation of marijuana and tobaao In dogs: Pulmonary
<br />rives from animal studies In which morphologic and physiologic pathology. Ra. Commun. Cham, Por 10bitil- PhorIn dog 1Pulmo317.
<br />evidence of emphysema was found in rats exposed for 6 mo to 6. Fleischman, R. w„ D. W. Hayden, M. C. Braude, and H. Rosenkranz.
<br />tobacco smoke, but not in rats exposed for the same period to 1975. Chronic marihuana inhalation toxicity in rats.
<br />smoke from a comparable quantity of marijuana (32), Phonriecaf. 34:467-478, Totkol. Apps.
<br />Peripheral deposition of inhaled particles in the lura depends 7. Fleischman' R. W., J. R. Baker, and H. Roscnkrantz. 1979. Pulmo
<br />largely on particle size If particulates in marijuana smoke were n9arry a noal-vg i changes in rats exposed to marijuana smoke for one
<br />substantially larger than those in tobacco smoke, it could be ar- 8. Fligid, S. E. G., T. F. BeeisnD. P. Tashkln M O. Pause, A. C. Scallct,
<br />gued that these particulates do not reach the small airways and S- V Ali, J. R. galley. and W. Slikker, Jr. 1991. Marij nano cxpoaurc
<br />alveoli as efficiently as the submicronic panicles In tobacco "it Pulmonary alterations in mates. Phormptpl. 8rothem.8ahay.
<br />smoke, and are therefore less likely to cause tissue injury at those 40:617-642'
<br />sites primarily affected in COPD. On the 9. Huber, G. L.. V. B. Pochay, W. Pereira, j. W. Shea, W C. Hind$,
<br />other hand, obacc - M. in past, and O. C. Sorobbacte 1980. Mad)uana, tctrahydrocan•
<br />notate measurements Of particles in marijuana and tobacco nabinol, and pulmonary anr;bactcrial Qcfcnsn. Chess 11:403-4I0.
<br />smoke, made with laser Doppler velocimetry techniques, have to. Rubin, V., and L. Comius. 1975. Rnpl dt fcn m on and 403-41 l -
<br />confirmed that the mass median aerodynamic diameter of the oar• fn oanja In Jamaica; q Medica! Anthropological cal Study of
<br />particles from the two types otsmoke are comparable (approxi_ Chronic Marihuana use. Mouton, the Hague. g7_IO2.
<br />mately 0.5 µm) (33), thus refutiog this argument. If. Cl opra,as. 1973, Stud es Mouton,
<br />The Has
<br />The results of the present 8 -yr study also contrast with find• runt use in 124 cases. 1171, !. Addirr. 3:1015-1026. tem Mari_
<br />from a short-term prospective study(34) that demonstrated 13 Hlmv ct on United Slsuero5eturityaJn Herrings of the Committee on
<br />an accelerated decline in FEV, (approximately 3% of baseline) 1 Hashish Epidemic and lis
<br />Or-
<br />in 28 heals J Y 'h eJ Judiciary, United States Sena It U.S. Government Printing Of-
<br />hy male marijuana smokers over only 8 to 9 wk of Washington, DC. 147-154.
<br />much heavier than usual exposure (mean of S joints/d, compared 13. Herrnnda-Rishm s, l., E. W. Swenson, and W. J, Co
<br />with their customary use Of an average of I joint/ ervation of pulmonary function in regular , heavy, ong_t 1976. Pre•
<br />after cessation of this unusuallyhu �t One month ana smokers (Abstract). Am. Rev. ea r, long-term:joo-
<br />vy use, the latter subjects to,, aoulouaou.ia, J. C., C. P. PanaNue Du. I13(So. A.):100.
<br />exhibited a rdurnof their FEVs to baseline. Although it is diffi• chronic
<br />a, n. Acts
<br />cult to explain the discrepancy end C. SteAnia, 1976. £flints of ch onich �a"v sit. P ry between these two prospective tua in 44 users compared with 38 control Amt. sK.. Y. Acad. e on l&i.
<br />studies, it is possible that the participants In the Short-term study 2g2c168-172.
<br />(34) experienced a temporarily steep step -decline in their lung 15. Tashkin, D. P„ A. H. Cwhan, V. A. Clark, M. Simmons, L. B. Bour.
<br />function, after daily exposure of their airways to much more quq S.Duann,G.H.Spiv
<br />ey, and He , Gone1987. RespiratorysYmp•
<br />roma and h+"a function In heavyaabitual, ary uaokvs or mar(juana alone,
<br />
|