ets exposure, lung cancer - Legacy Tobacco Documents Library

ItLGUt .wT0ttY TOxtO01aGY Ar+D ?IiwlwAcotlxtY 19, 309-316 (1994)
lncanslstency between Workplace and Spousai Studles
of Environmental Tobacco Smoke and Lung Cancer'
IvSAUR1CL• E. LL•VO1S" AND MAXWELL W. LAYARDt
'F.nriroemental Nrahh Re .rourcrr, Ttbu,on . Calijornla 94970~ and tLayard .lrsoclates,
Alomrda, Ca!(/ornia 94301
Itccefvcrf January 10. 199!
!n a t'isk astessment ssteased at thc end o( 1992, thc U .S . Environmental Protcetion A ;cncy
(EPA)condudeG that environmental lobacea smokc (ETS) Is a known hunu,n lung urdnotea .
The A=ency re.ached that eondusion primarily on the buis of epidcmiolo5ie nudtee of self .rsponed
nevcr•smokin; women, in which the ext>o:ure index was marriagc to a smokcL llowvver, the tuc
of the spousel smoking expoaure surmpate introduces many potcntiat wn(oundinR fseton . Such
confoundins and bias due to denial of activc smokin6 art likely aplanations for weak and in•
consistent rer»nod L•TS-lunz csncer assnciasions . This contention is tupponed by the ruults of
1A wortdvdde studies of lunl pnetr and ETS exposure in the workplacc . which in wmbination
indiuted oo risk elcvation . Wnrkplaoe ETS-luaS uncct• studics are not subjoct to the bias and
confounding intsoduaed by the spousal smoking exposutt surrosate. The t:PA Ignored thc workplacc
studies ln its risk auesamont and eatrapolatad the resulu of orwtsaal smoking nudiet to
workplxx and other sourtrt of LT'S exposurt : In its enimate of ETS•ataributable luna< cancer
deaths in the Unitod Sutes, the EPA asc :ihed over 70% o(thc deaths to nonspousal 1`I'S c~+osurt :,
primarily workplaee ezpocure, Considcrt:d in their entirety, she ETS-lung cancer enidenioloaic
data do not suppon a uusal infcratea or provide a tcientihc boais for sovernmcnt reSulation of
smotiing in the workptace. o t»r Aols.mK t•rWl, tr.r .
1 . INTRODUCTION
The U .S . Environrucntal Protection Agency (i=.PA) recently issucd a risk assessment
of lung eanccr tnonality and environmental tobacco smoke (ETS) exposure (U .S .
EPA, 1992) . Tlte EPA report calculated a sumtnnry relative risk oC 1 .19 (909'o confidence
interval, 1 .04-1 .35) from a meta-analysis of results of 11 U .S . studies (9 csse-cantrol
studics and 2 cohort studies) of reportedly never-smoking female subjects. (In a depnrture
from conventional prnetice, the EPA citcd 90% confidcnca intervals for reJativc
risks, on the basis that they corresponded to one•tailed 5% sSgnificance tesu ; a 95%
con5dence interval for the summary rclativc risk is 1 .02-1 .39 .) These studics used
t This work was supported in pan by Thc Tobaero Institutc . The vic-x expressed rrprncnt the pcrsonal
opinioas of the euthon and are not neaessariiy those o(Ths Tobacco lnstitutc,
0273-23W/94 T6.00
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http://legacy.library.ucsf.edu/tid/wyk81f00/pdf
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