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A
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<br /> -%UTOHOTI-TE GASOLINE
<br /> y
<br /> signer At one nigri-volume station. zhe mean concentration to wnicn an
<br /> individual filling his own tank of. gas was exposed (for ten minutes)
<br /> was 4 2 ppm (2283)
<br /> 65 3 HUMAN HFALTH CONSIDERATIONS
<br /> 65 3 1 Animal Studies -
<br />-- --------65.3.1.I--Carcinogenicity— ------ ---�-
<br /> _r
<br /> Host o£ 'the evidence regarding t' carcinogenicity ofj' gasoline , has
<br /> been provided by a study, conducted for- the American Petroleum Institute
<br /> (API) (2298) ;'.,,,Report3' ,,of this, study, 'ppear in several,forms throughout
<br /> the literature'.r,` A-' chronic inhalaion 4,stu4y,� of ,gasoline vapar' !was
<br /> i l , i ' !,1 v % F , W" , N h t i r
<br /> conducted yin mice,sandIrats;+ ,thep,gasoline�}emplcyed'�was unleaded; with
<br /> n 4 ^ ' Ir" s Lk m a.-r,.rr r1 4 ( 9 ! ' r r r t
<br /> the' benzene content `adjusted scop `21: isaGroups ,�of both`;,'sexes orf 96C3F1
<br /> mice` and schrer,,,-.344` rats were `expos'ed' 'to' ',vapor ar. con'centrations� of
<br /> ' 67;' 292,,o'r 20561Ppm �fcr '6i"h' aurs ,per day,, ,, 53, days per,, eek for periods
<br /> ran' 'from's103' ta' 113 ,weeks., After as Little as three 'months o£
<br /> exposure- to, 2056 "ppm.' macroscopic lesions were evident-'in the kidnev, of
<br /> male rats. Microscopic observations -xneluded an Lne=eased inCLdeIICe of
<br /> n ,rr tr spj ( w e
<br /> renal disease 'with 'r,tubular degeneration,, - regeneration or ;cystic
<br /> dilatation among„ males.- exposed to,i 2920•� orv12056 ppm: ' �•Atrc`;24 month's an
<br /> y Y' t 7 J i N f '
<br /> increase' in ; the �occurrence`,�'o'f� primary;,+,renalo'1neoplasm,was seen„ xrx the
<br /> � �. r
<br /> male rats at all doses„ with some^;evidence of a, dose-response relation-
<br /> y 4 r - , 7 " $f r �s a �r i f t-u— s
<br /> ship. Yti additfon,j a,%compound related. increase' in liver nodules and
<br /> masses' was seen in)°female'"MLce exposed .tc` the"""intermediate and high
<br /> levels. Histopathola'gzc{;"examinations Irnveeiled,,,,,primary' hepatocellular
<br /> tumors (adenomas s and,icarc LIIomas) in'thea e%.inirsals:
<br /> TheSol unaxpected,'findtngs`of, species,and sex-specific carcinogenic
<br /> effects-,were h note 11
<br /> vident aunt LV Late 'in', the`, satu'dy,,_',', To,zbetterunderstand
<br /> p ,r I "I L , i, r i L v. r, ,rg , r ( r
<br /> the sxgulficance' eo. humanThealth, the'American,3'Petroleum Institute con-
<br /> tracced ,wxr-h Unive=sitie9l' Associated' for'', Research 'and Education in
<br /> Pathology, Inc. (UAREP) for assistance in interpretation of the find-
<br /> Lngs. - The UAREF- reviewed the chronic inhalation study, "old rat
<br /> nephropathy" syndrome., and the basic morphological and functional
<br /> similarities and differences in the kidneys of- the rat, mouse, and man
<br /> (2299) This ' review concluded that the ' `significance of the
<br /> hepatocellular carcino�ta in : female mice was questionable. The UAFLEP
<br /> felt that `other studies on ' differenc hydrocarbons demonstrated acute
<br /> toxic effects on the female liver including fatty metamorphosis whereas '
<br /> these effeccs� were Inoc reported in the API chronxc inhalation study
<br /> _
<br /> The finding of renal carcinoma in male rats was clearly
<br /> significant. The lesions were seen as earlyr,"as 90 days and were
<br /> dose-related. 'The lesions could be clearly distinguished from the old
<br /> rat nephropathy„ ” which is composed of chronic lesions involving all
<br /> components o'f,',the kidney However, administration of unleaded gasoline
<br /> appeared to '' accentuate all the Lesions characteristic of old rat
<br /> riephropathyt itwasnot possible to evaluate the potential role of the
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<br /> 6/87
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