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FILE NAME: Shipbuilders Council of America (SHIP) DATE: 1976 Dec DOC#: SHIP049 DOCUMENT DESCRIPTION: Journal Article - Occupational Differences Rates of Lung Cancer Occupational Differences in Rates of Lung Cancer Herman ft. Menek, M .B.A.; and Brian E. Henderson, M.D. M a n y investigators have associated lung cancer with occupa tional exposure.' 17 In an earlier study, we reported an excess of lung cancer in males in the industrialized south-central area of Los Angeles County. This may have been the result of air pollution of industrial origin, specifically, elevated levels of polycyclic aromatic hydrocarbons.'* However, since the excess was confined to males, occupational exposure would be an alternative explana- "in ' Interest in better understanding the different factors affecting lung cancer in Los Angeles County, in drawing clues toward identification of high risk occupations, and in setting a base line for future occupational observation and control programs led us to review five years of lung cancer data for white mates in the county. Methods Subjects. -- All 2,161 death certificates mentioning lung cancer (trachea, bronchus and lung! in white m ale), ages 20-64, for the period 1968-1970,* and all 1,777 incident cases of lung cancer in white males of the same age group reported to the Los Angeles County Cancer Surveillance Program (CSP)" for 1972-1973, were reviewed. These m ortality and morbidity data w ere pooled; we consider this justified because of the high m ortality rate of lung cancer and the relatively high accuracy of death certification regarding lung cancer. " During this reporting period, the CSP abstracted all Incident cancer cases from 198 hospitals and six private laboratories in Los Angeles County, including all hospitals known to treat cancer. The primary source of case selection was hospital pathology files, including hematology, cytology and autopsy reports. The medical chart was reviewed when necessary to establish primary site, tv first date of diagnosis of the m alignancy, or to determine missing demographic data. Pathology records of nearby out-of-county hospitals w ere searched for in clusion o f residents of Los Angeles County who were cancer itien ts. A ll Los Angeles County death certificates mentioning malignancies w ere reviewed to further Insure completeness of in- from the University of Southern Ctlifornla, School of Medicine, Department of Patho lo g y, 262S Z o n al A van ue, Los A ngeles, C A 90033. Journal ol Occupational Medicine/Vol. 18, No. 12/0ecember 1976 cident case ascertainm ent. The study was limited to the age group 20-64 to minimize the number c f retired persons without Stated occupations. O f the 3,938 subjects, 689 (424 deaths, 265 incident cases) had no reported occupation, and 1,222 (619 deaths, 603 in cident cases! had no reported industry of employment C lassificatio n of O ccupation. -- O ne occupational title, and one industry of employment were obtained per subject California death certificates include the subjects' last occupation, name of last employing firm, and type of Industry. The CSP demographic data w ere abstracted from hospital admission sheets, and in some cases medical records, and represent the last occupation and in dustry of employment w hich the patient or next of kin reported at admission. The occupation and industry o f each subject were coded Into one o f 417 occupational codes, and one of 215 in dustry codes, per the 1970 U.5. Census occupational classification system ." A n alytic M ethods. -- Detailed occupation and industry populations-at-risk for white males In age groups 20-24, 25-34, 35-44, 45-54, and 55-64 w ere developed from the two Pubfc Use Sam ples (PUS) of Basic Records from the 1970 Census for lo s Angeles C o u n ty." These included respondent inform ation on current occupation and industry. Combined use of the two PUS provided a 1-in-50 sample of Los Angeles County, There were 31,216 white males, aged 20-64, in the combined sample. Expected deaths and expected incident cases were calculated for each specific occupation assuming the age-specific rates of cancer in each occupation w ere the same as those for ail occupa tions. The ratio i%) of observed deaths plus Incident cases to ex pected deaths plus incident cases, hereinafter referred to as a Standard M ortality Ratio (SMR), was then used as the measure of risk for the individual occupations. In a sim ilar w ay, an 5MR was calculated for each industry assuming the age-specific rates of lung cancer in each industry were the same as those for all industries. The Mantel-Haenszel method was used to measure statistical sig nificance." Results The occupations with statistically significantly increased Stan dard M ortality Ratios for lung cancer are listed in Table 1. Among 797 the populations in these occupations there were 942 observed lung canters compared to an expected 537 cases. The Standard M ortality Ratio for lung cancer among these combined workers was 175. There w ere 16 occupational groups with an SMR of 200 or greater. Tw enty-nine percent of the lung cancer in males ages 20-64, w ho reported an occupation, occurred in the high risk workers listed in Table 1 who comprise only 15% of that sex-age group. The number of deaths (1968-1970), and the number of in cident cases (1972-1973) w ere listed separately; the proportion of lung cancer cases from death certificates and the CSP was con sistent across the occupations listed with few exceptions. A ll but one of the high risk occupations were among craftsmen, opera tives, laborers, and service workers. There were two occupations, bookbinders and blasters, which were calculated to be at greater than fourfold risk to lung cancer, but where the risk calculation was based on so few cases that any inference drawn would be speculative. . There were 16 occupations with an SMR below 70, including pharmacists, assemblers, cranemen, physicians, barbers, foremen, sales managers, checkers, judges, secretaries, teachers, personnel workers, dentists, stock brokers, photographers, and school ad m inistrators. The Standard M ortality Ratios of workers in Los Angeles County to lung cancer by Industry are given in Table 2. W orkers in 13 in dustries were at significantly increased risk w ith SMR's ranging from 127 to 279. Forty-two percent of the lung cancer in males reporting an industry of employment, age 20-64, occurred in these High risk workers who comprised 27% of that sex-age group. The proportion o f lung cancer cases from death certificates and the CSP in these industries were consistent w ith few exceptions. Discussion There were clear occupational differences in rates oi lung can cer among white males in Los Angeles County. These occurred by broad occupational group, and by Individual job classification. However, there are lim itations to the epidemiologic techniques used and, whelher these risk differences w ere the result of occu pational carcinogens, or reflected differences in smoking habits and other factors le.g., general air pollution), cannot be deter mined. Thus, the absence of information on smoking limits our ability to delineate the risk of lung cancer due to occupational ex posure alone. However, the pattern of these Los Angeles data, their consistency with earlier reports of excess lung cancer risks in certain occupational groups (asbestos workers, machinists, cooks, painters), and their consistency w ith reports of other occupational diseases related to airborne agents (skin cancer, silicosis, ashpstosis, pneumoconiosis, bronchitis), suggest that the data may be generally indicative of the im pact of occupational exposure on lung cancer rates. Occupational groups found to be at excess risk who have not been previously implicated included roofers, dental lab techni cians, decorators, nonautomotive m echanics, photoengravers, 're-' t r t s t P r jv - , - - -* ' A r*-'- ; w j p s is .i* 'a r f ~ S tan to n Mortality Ratios (SMR - 100 hr-'/tit Oacuaatior*) h r O w w th M at Siptffleanrty h ira a in t 8M t - * *JW* c,n<*r- *W ta ^Maa 2 M * in n , L a i Anjstw C an ty. / - iv v S r^ '' 1 V - \ I*V ", h -.'.i t vfc v . t O ccu p yf " Astasias, twmHar Worim ' ** s'l& vr Heal tM e rS K S fe*-;. ,, ' ,, K -. ,v J< y. OmM _ -' Tu MKMnteL v ciooiw* f c r w a t f ^ w s i - M an n .. Sha M m 0lm w iSi^:S*,-~> EUdricw*' 8irtmdB-.-ySSi's?SSif.ll riastnm . 0rr.W U .m A n . CfMk* . ' Msdinr Shge'VW wvv. , True* Drew* ^ ' V ' " ` IbrM m tjwr ' Painter* Plumbers t- ' -i , > W tU m Ism tn ` * " - ' V 4" VrV. * . t C4- * .. ' - Subtotal ,- ' 3r - Ml Qccuptki* ' y +11 so d ota4p < 0.0& , afca jXQjQl . t i u m r ' PcpnlMtar n*h ^ ; * MM <231 *' 'p- , f * * . Of Deaflt* 1998*1970 WO - - 3 2,000 ` ' ' V 6 550 `^ 1 ' M0 -V" 2 1200 3.100 < '\ * - ' 6 r 16 9.090 . V IS 1JM ' -V- 4 5.300 `V 10 1.100 '5 - V ' 1 3450 - ' ' r `s'v ' ' 1450 9 -S - ' 3 1250 12,400 * *V\, s . 40 7.100 . "`V . 3200 ' 16 . 3 11.450 62450 > 117 34400 ' .` 58 8,150 19400 -f 18 . 45 9.700 25 15.300 21 27.050 41 231500 904 1560500 ' - V 1.73a la a iiir il'f'y ,' Cm ' la T a -iw j ^ ` , z . rc S ` iv sm - 978 -.'S'' ` % 498 . ' " a :.. = 433r- ; kb ' i ' =* 358 344 ~tr -4L^; *ai 332 . M- t - s s w n 320 " ! lO ffA -V `7 m m 1 j J ^ `<268 * - ' ^ u y z n * i 3"" \-*! I - ='>7- 217+' J ;!Vi- 2 ` 10 - V ~ i '-2 0 4 . i 14 ^ - 209 J 18 ' 180 92 -/* * 167 51 . - . IfiS It ` - 15* 42 158 U 138+ 27 . 137+ 81 , , 127 438 178 UMl 100 ,. ,, Va- ; .0 ' ' i 798 Occupational Differences in Rales ol Lung Cancer/Menck and Henderson clothing itoners, electricians, bar and restaurant managers, and unitors. O ccupational groups found at high risk who have been red elsewhere included asbestos workers,21 n heat treaters," r ,ne shop w orkers,1` s 1)1 pressmen, 2 ,?-a longshore men,* 14 15 shoe repairm en,1 1 " mine operatives,' ,s bartend e rs ,1 ' 15 p la s te re rs,' " c o o k s,5 " ' * ta xi and tru ck d rivers,1 s 11 15 w p ain ters,1' 4 11 " plum bers,3 ' " '* and welders1 " u Industry groups not previously implicated include radio-TV broadcasting, dairy, leather, food and drink, bakery and auto repair Industry groups at high risk to lung cancer in Los Angeles County which have been previously reported include steel,10 paper,31 petroleum refining,11 and transportation.11 No significant risk to lung cancer was detected among chemical and rubber workers; both grouos have been found to have elevated risks in other studies.1* This discrepancy In our data may be due to the small number of such workers in Los Angeles County and to geographical variation in the types of exposure w ithin the industry. M ost of the risk to lung cancer associated w ith the high risk occupations and industries listed in Tables 1 and 2 m ay be related to exposure to asbestos or p o lycyclic aromatic hydrocarbons (PAN) or both. Asbestos has been identified as a potent car cinogen both in animal studies and in occupational studies of hum ans.15 15 15 14 Besides asbestos (insulation) w orkers, ship and shipyard workers. Including stevedores, have been reported at ex cess risk to lung cancer elsewhere." 11 " Other risk groups who ` . . . y- " . - - - **- - 4* TsWs i -- Stmted humility MtM (SIM 100 hr AH M attM f U * Cmmt, ' ": - 1 Industry. White Maks IM * Yens. Lot hip k i County. _ j Indirtry fn h a iM ,vf i . ^ PoprtHaii Tr! ' "vT- - / t m t t Site Mf( "r ' RtK>, TV Broadcastr f Dy Mfj #nd $lla - fit t e r Mff 4 Sale* - Eatn^, Orb*mi f t m ? * m Mt| tm a * . Bator Mil rad S iln Patrafeurn. Coal PnMs Otto fool Auro FfcjM Transport Eqt Mjg I Saltt Pu^tc Mimnhtrvtiw trm aw lilia Otto Midi M%. . TiUqtxnt. Ttlepe* Etatfiol Matfi H tt le u * , tprml twntwr. Wort. Fumt o n am k* utiliiiw. S w a n Stole, Butt* Sian. cuy. ea st Printmi, Heiacapaa fbtm lkn PRunal S n k n Oun*t* R*pM Sernas Other Betid Trait Minni Construct*# PUrtc NcitflK. Mats Mis. Flwet, fasnrai Rto E lb e riot Ept. m ii. PrtfBtuwl WNriruk frada A|rk, Foratar, Ff$toM r ~y<.' t * /U ' C v - ,K ' .ft/ ` s',1 'V t h t" V ''< ; ' , - c , - v- - ,, * - : 1 ( * V , ' - Alt Indjftria 10900 v 5.700 *50 3 5 ,(0 0 11.900 s i 7.900 17500 121SO 154550 82.950 7*690 *7350 2Q.6M 97500 19.000 ,i 1U M 7W O J 6,450 13,750 87,850 47,900 32J 0Q . 64.600 136330 1700 1H 7 7m 58800 73.950 67500 163300 00500 15350 15 6 0 8 0 0 ," 1 - ` Ik. s( Om In m um 39 10 10 6 59 14 19 U 19 20 73* 73 92 57 0 69 27 2d u 25 t 18 38 51 41 63 122 12 187 6 49 - 43 20 74 43 10 1,5 *3 . ' CM 197*1973 -$& - j -t '* * 816* 15 19S* 8 V 3? . u - - i 7r m~ - I'is r 13 1W n 14T i s l - * 203 - MJ* 1 96 1S T , 74 i 22* ; 47 m M . ,1 3 > 84 ' ^ 1W ' 1 20 1 ; ns 19 ' - 114 ' 14 llfr 19 V? ; m t , E / -- -MS 7 ; r .j .. 18 . '''* 9 29 / to r --J -91 n 69 i* OS . 5 85 49 W 5 84 , 23 82 48 7 & 83 58 26 <8 3 46 1.173 soo N|h. (MtO.01 f* W 4NMtfy hrfh. p< 0 0 5 Journal of Occupational Medicine/Vol. 18, No lZ/Oecember 1976 799 may have been exposed to asbestos include clothing ironers, plasterers, dry w all workers, electricians and plumbers. PAH compounds have also been identified as carcinogenic In animal and human studies.1* Exposure to PAH compounds is very characteristic of metal working occupations, and several of these occupations were at excess risk to lung cancer in Los Angeles C o unty, including heat trea ters," m etal m achine shop w orkers/* 41 w elders/1 and plumbers, in addition to these groups of metal workers, steel industry workers in lo s Angeles County, __when analyzed as a single group, were also at elevated risk to lung cancer. Others have reported elevated risk o f respiratory disease, including lung cancer, in steel Industry workers." 41 47 O ther groups at high risk to lung cancer who have probably had ex posure to PAH compounds include roofers/* vehicle d rive rs/*'54 employees of auto repair companies, photoengravers/5 printing trade pressm en,27- 21 " 54 52 cooks, bakers, em ployees of petroleum refineries,1* " and dental lab technicians." fo r (he remaining occupations and industries at excess risk to king cancer, specific carcinogenic hypotheses are difficult to propose. Shoe workmen and repairmen have been previously reported at excess risk to lung cancer.1 * 11 Several investigators have also reported excess nasal cancer in the boot and shoe in dustry, w ith the excess apparently associated w ith the leather and cork dust areas rather than the spraying and lacquering areas.** *1 Besides shoe repairmen, other workers in the leather industry also were at excess risk in these Los Angeles data. SMJt's of H O 11 and 1404 have previously been reported for such leather workers. Bar tenders have previously been reported at greater risk to lung can cer, but to our knowledge no carcinogenic exposures have been suggested, it is possible that these bartenders are heavy smokers, have had heavy exposure to smoke filled barrooms, and thus smoking may have produced an occupational artifact Janitors have seldom been reported at excess risk to lung cancer,2and it is possible that the relative weakness o f their risk and their low social class may be indicative of a smoking rather than an occupational effect M ilk has been studied as an eluant of polycyclic aromatic hydrocarbons added to w ax,42 but w e are aware of no other data Suggesting excess risk in dairy workers. Further Investigation of worker groups described herein and their relationship to lung can cer would seem w arranted Summary ' Lung cancer rates in Los Angeles County w ere reviewed for dif ferent occupations and industries. Employment groups found to be at excess risk who have not been previously implicated in cluded roofers, dental lab technicians, decorators, nonautomotive m echanics, photoengravers, clothing ironers, electricians, bar and restaurant managers, janitors: and workers in the radio-TV broad casting, dairy, leather, food and drink, bakery, and auto repair in dustries. Most of the occupational and industrial groups found to be at greater risk to iung cancer in Los Angeles County had ex posure to asbestos, polycyclic aromatic hydrocarbon compounds (PAH), or both. ~ Supported by Contact No. NO1-CP-53S00 and Cunt NO. K> ICA 170544)1 from die National Cancer kirtitute. 'Oeath certificate data were kindly supplied by Maitm Donabediin. Lot Angrier County Department of Health. 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