Original article Scand J Work Environ Health 1976;2(1):27-30 doi: /sjweh.2824

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1 Downloadd from on Novmbr 6, 212 Original articl Scand J Work Environ Halth 1976;2(1):27-3 doi:1.5271/sjwh.2824 Eight-yar follow-up of viscos rayon workrs xposd to carbon disulfid. by Hrnbrg S, Tolonn M, Nurminn M Th following articl rfrs to this txt: 1989;15(4): Ky trms: carbon disulfid; coronary hart disas; follow up; follow-up study; intrvntion; viscos rayon workr This articl in PubMd: Print SSN: Elctronic SSN: X Copyright (c) Scandinavian Journal of Work, Environmnt & Halth

2 Scand. j. work nviron. & halth 2 (1976) 27-3 Eight-,yar follow-up of viscos rayon workrs xposd to carbon disulfid by SVEN HERNBERG, M.D., MATT TOLONEN, M.D., and MARKKU NURMNEN, Lic. Sc. 1 HERNBERG, S., TOLONEN, M. and NURMNEN, M. Eight-yar follow-up of viscos rayon workrs xposd to carbon disulfid. Scand. j. work nviron. & halth 2 (1976) An 8-yar follow-up of workrs xposd for at last 5 yars to carbon disulfid showd an xcss of daths du to coronary hart disas in rfrnc to a comparison cohort. Howvr, aftr ffctiv prvntiv masurs,.g., laving only 19 % of th original group xposd and rducing th lvl of xposur to lss than 1 ppm, had bn undrtakn aftr th 5th yar of follow-up, coronary mortality dcrasd and no xcss mortality during th last 3 yars of follow-up occurrd. Ths rsults, although only suggstiv - du to th small numbr of daths and th short tim of follow-up aftr th intrvntion - sm promising from th point of viw of improving th prognosis of workrs who hav alrady accumulatd an xcss risk for coronary dath. Ky words: Carbon disulfid, coronary hart disas, follow-up study, intrvntion. A follow-up study of th ffcts of carbon disulfid (CS 2 ) xposur upon th incidnc of coronary hart disas (CHD) was startd in A cohort of viscos rayon workrs, xposd for at last 5 yars to CS 2 during any priod btwn 1942 and 1967, and a comparison cohort from a narby papr mill formd th groups undr study. Th mmbrs wr matchd with rspct to ag, birth district, and typ of work and xamind for th prvalnc of symptoms and signs indicativ of CHD '(7). Th rsults of 1Jh first 5 yars indicatd narly,fiv tims as many daths du to CHD in th Xlposd oohort as in th comparison cohort; also th incidnc of nonfatal infardions,was lvatd (3, 7). Whn 1!hs rsults bcam known, vtgorous,horts wr mad to doras th risk. '.Dhyconsistd of tchnical improvmnts in th work conditions, transfr of 1 Dpartmnt of Epidmiology and Biomtry, nstitut of Occupational Halth, Hlsinki, Finland. Rprint rqusts to: Dr. Svn Hrnbrg, nstitut of Occupational Halth, Haartmaninkatu 1, FN-29 Hlsinki, Finland. workrs with long xposur tim and/or symptoms of CHD to dpartmnts without xposur, and xtnsiv us of prsonal protctiv quipmnt during pak xposurs. This intrvntion changd th prmiss for furthr follow-up, which was thn continud with th purpos of possibly dtcting a downward trnd in CHD mortality. MATERAL AND METHODS Dtaild dscriptions of th xposd and comparison cohorts hav bn givn in prvious publications, and will not b rpatd (2, 3, 7). n short, both cohorts initially comprisd 343 mn, agd yars. By dsign th cohorts wr similar with rgard to ag distribution, birth district and typ of work. An a postriori valuation confirmd that thy did not diffr with rspct to smoking habits, lisur-tim physical activity, physical fitnss, rlativ body wight, srum lipids, and glucos tolranc. Th only significant diffrnc was found for blood prssur, 27

3 which was slightly highr in th xposd cohort, but this diffrnc was intrprtd as an ffct of xposur rathr than as an indpndnt risk factor. Th causs of all daths occurring in both cohorts during th follow-up priod from Jun 1, 1967, through May 31, 1975, wr vrifid from th dath crtificats Tabl 1. status of th xposd cohort in Jun Status Numbr J Still mployd at th plant Still xposd No longr xposd No longr mployd at th plant Rtird or pnsiond Movd Dad 35 1 Total and,classifid according to th ighth rvision of th intrnational classification of disass (8). NQ on was lost during th follow-up, which thus was 1 / succssful. As a basic masur of th occurrnc of dath w hav usd th 8-yar cumulativ incidnc rat. Th rlativ frquncy of dath has bn xprssd both as a ratio and as a diffrnc in th rat of th xposd rlativ to that of th nonxposd. According to th 5-yar data th xposur status of th viscos rayon workrs changd radically during th last 3 yars. Tabl 1 shows that only 19 Ufo of th mn wr still xposd to CS 2 as compard to 53 Ufo 3 yars arlir (7). During th sam priod th CS 2 lvls fll sharply, and hnc vn th 19 Ufo still xposd had much safr working conditions than bfor (figs. 1 and 2). Th C~ factory had casd to xist, and viscos film was no longr bing producd. At th nd of th 8-yar {,ollow-up, th man ag of both cohorts was 53 yars \ E.. a. a. 4 z o ~ 3 : w 2 () o () ''''. Xanthation room.---. Viscos ripning room - Spinning dpartmnt ()._-() Spinning bath room, n= 1-29, N=2491 n= 1-18,N=248' 9-15, 2-4, n=2-36 N=455! 18-29, 1 n= 1-3, N=3~ 25-39, ,,.. : ~ (L\/~" i:: r. 4-, '--~~--~tt , , , ,16 o Fig. 1. Concntrations of CS2 + H2S in th rayon stapl fibr factory. Not th dcras btwn 1972 and

4 r-:ll~(.::-::13:-:c1)= ~-----' '1----, - 8t--~-- 6 E Q. Q. 5-4 <t: : - W U 3 U 2."~ Xanthation room Viscos ripning room _ Spinning dpartmnt ~ Spinning-bath room n=6-23,n=215, 11-18, ,49 n= 2-22, N=345' 8-15, 59 : 3- S, 14 n= 3-22 N= , ,86, n= 3-22, N= , , Fig, 2. Concntrations of CS2 + H2S in th rayon filamnt factory. Tabl 2. Obsrvd numbr of daths among th xposd and comparison cohorts during th 8 yars of follow-up, and stimats of crud rat ratios, by caus of dath. Mortality Exposd Cohort Comparison Rat ratio 95 1 confidnc intrval Total CHD During th last 3 yars RESULTS Tabl 2 shows th accumulatd total and coronary mortality of both cohorts. Th 8-yar cumulativ incidnc rat for CRD mortality was 5.8 % in th xposd group and 2.6 % in th comparison group, th rat diffrnc bing 3.2 Ofo. For total mortality th corrsponding cumulativ incidnc rats wr 1.2 % and 6.7 /, rspctivly. Th rat diffrnc of 3.5 % was almost idntical with that for CHD alon. This rsult indicats that CHD was totally rsponsibl for th xcss mortality. Howvr, during th last 3 yars of followup, th sam numbr of daths, or 6, from CRD ocourrd in both cohorts, and rduting th 81Jh yar thr was only on HD dath in th Xlposd cohort against thr in th comparison cohort. ':rhus a shift in th trnd sms to hav takn plac. Ag-spcific data indicat that th xcss risk of CHD was strongst in th ag rang of 5 to 64 yars. n all, 17 of th 29

5 2 coronary daths of th xposd workrs occurrd in that ag rang against 5 in th comparison group. A mor dtaild analysis, togthr with a calculation of th lif xpctancy in diffrnt ag catgoris, has bn rportd lswhr (5). DSCUSSON Whn intnprting th data for th 61Jh through th 8th yar of follow-up, 'whioh actually did not Show any ~css of CHD in th xposd group, on must considr th drastic chang in xposur status. Only 19 % of th original cohort was still xposd, against 53 Ofo in Th rst of th survivors had movd away or had bn rmovd from xposur. Furthrmor, th avrag xposur lvl was wll blow 1 ppm for thos still xposd. Thus thr is no contradiction btwn th prsnt rsults and thos prviously rportd by us (3, 7) and othrs (4, 6), according to which xposur to CS 2 incrass th incidnc of coronary daths. n fact, Tillr t al. (6) hav alrady pointd out that th xcss mortality found in th 194s tndd to lvl off with improving hygin in th 195s and 196s. n th prsnt study th small numbr of coronary daths occurring during th last 3 yars of follow-up (6 in both groups) prvnts th drawing of dfinit conclusions, but th fact that th vn distribution coincids with th changd conditions suggsts that th xcss risk is rvrsibl. f tru, 'such a finding would b of both practical and thortical intrst. Bsids proving th prvntiv ffct of lowring th xposur lvl, th data suggst that rmoving prsons with indications of CHD from xposur rally dcrass th risk for futur fatal attacks. Th thortical intrst lis in th fact that, if th ffct of CS 2 is indd rvrsibl, th xcss mortality occurring undr xposur is du to a dirct toxic ffct upon th myocardium rathr than to an acclration of th athrosclrotic procss (1). Furthr follow-up of th cohorts is now primarily motivatd by th nd to tst this hypothsis. ACKNOWLEDGMENTS Ms. Pirjo Fahlstrom has onc again collctd th mortality data with grat prcision, and w wish to xprss our sincr thanks to hr. REFERENCES 1. CHANDRA, S. v., BUTLER, W. H. and MAGOS, L. Th ffct of carbon disulphid on th myocardium of th rat. Exp. mol. pathol. 17 (1972) HERNBERG, S., PARTANEN, T., NORD MAN, C.-H. and SUMAR, P. Coronary hart disas among workrs xposd to carbon disulphid. Br. j. indo md. 27 (197) HERNBERG, S., NURMNEN, M. and TO LONEN, M. Excss mortality from coronary hart disas in viscos rayon workrs xposd to carbon disulfid. Work-nviron. halth 1 (1973) MOWE, G. Coronary hart disas and occupational xposur to carbon disulfid. n: D. DJURC, L. GRAOVAC-LEPOSAVC, A. POSTC-GRUJN and M. STANKOVC (ds.), Abstract: intrnational symposium on to toxicology of carbon disulfid, Banja Koviljaca, Yugoslavia, May, nstitut of Occupational and Radiological Halth, Bograd NURMNEN, M. Survival xprinc of a cohort of carbon disulphid xposd workrs from an 8-yar prospctiv follow-up priod. nt. j. pidmiol. (n prss) 6. TLLER, J. R., SCHLLNG, R. S. F. and MORRS, J. N. Occupational toxic factor in mortality from coronary hart disas. Br. md. j. 4 (1968) TOLONEN, M., HERNBERG, S., NURM NEN, M. and TTOLA, K. A follow-up study of coronary hart disas in viscos rayon workrs xposd to carbon disulphid. Br. j. indo md. 32 (1975) WORLD HEALTH ORGANATON. Manual of th intrnational statistical classification of disass, injuris, and causs oj dath. Author, Gnva Rcivd for publication: