Mortality intheBritish printing industry: ahistorical cohort study oftrade unionmembers inManchester

historical cohort studyoftheprinting industry wasestablished after ananec- dotal report ofacluster ofcasesofblad- dercancerina newspaperfactory in Manchester. Thecohort comprised some 9500men whoweremembersofoneor otheroftwotradeunions(theNGA and NATSOPA) in theManchesterarea between1949and1963. Duringthefollow upperiod (1949-83) 3482deaths occurred amongmenbornin1890orlater; follow upwas97%complete. Theresults ofthestudydonotsupport thehypothesis ofanoccupational riskof bladder cancerintheprinting industry. TheNGA haveastandardised mortality ratio (SMR)of63(95%confidence inter- val(95%CI)31-113) andNATSOPA an SMR of113(95%CI67-178) basedon11 and 18 deathsfrombladdercancer, respectively. Men involved innewspaper letterpress printing haveahighmortality fromlungcancer(SMR= 179,95%CI 144-218) thatisconsistent withthefind- ingsofprevious studies. Increased mor- tality fromcancerofthebuccalcavity andpharynxwasfoundforNATSOPA workers inthenewspaper industry; edi- torial workers hadanSMR of1053(95% CI128-3803) andclerical workers hadan SMR of638(95%CI132-1864). Thisis consistent witha reviewofpublished studies, whichstrongly suggestthat workers intheprinting industry havean increased riskofmortality fromcancers of the buccalcavityand pharynx. Socioeconomic differences inunioncom- position, ratherthanoccupational fac- tors, mayaccount forthelowermortality intheNGA comparedwithNATSOPA. The NGA, a craftunion,had an all causesSMR of 92 (95%CI 88-97), whereasNATSOPA covered a broader spanofoccupations andskill levels, and hadan allcausesSMR of112(95%CI 106-117); theNATSOPA andNGA all causesrateratiowas 1-21(95%CI 1.13-1.29).