Document jNaXb7xoLJzRkoNz7nr8VwwwR

fMGE hl;blCAl I InRARY NOTICE: This Material NORTHERNCALIT0Rt;'lA Ii[.ILIH L'EN~ER rnav be orotected by cowwht 246 SAN FRANCISCO. CILIFORNIA - LEmE.HIA MORTALITY IN ELECTRICALWORKERS MENGtAYD AND WALES SIR,-TWOreports'~' from the United States have suggested an association between electrical occupations and mortality from leukaemia, the greatest increased risk being from acute leukaemia, particularly acute myeloid leukaemia (AML).' Two independent analyses on England and Wales mortality data have been used to examine this hypothesis. 1970-72 data collmcd for a report on occupationd mortality' were reanalyscd. To avoid nurncratorldenominator biases the analysis wasconfined to proportional mortality ratiw(PMRs)based on all deaths in males aged 15-74. Table I shows PMRs for all leukaemia and for lymphoid and myeloid leukacmia(all and acute) for a11electrical occupation^.^ Thedistribution ofmonalityofthcse occupations taken together is not significjntly dflerent from expected. There arc consistently raised PAW, however, for the last four occupations in the table, particularly for AML. Proportional OccuparionaUindurtrial group All ckcrrical acupatiom and pnonr of any occupation engagedin an electrical or telecommunications industry All electrical muparions Electrichns and electrician's mta Electrical and electronic engineers Port Ofice and telephone CngineCn Other tckcommunicationr engineers. Power station. substation. and all RR 2.1 2.1 1.6 1.8 3.0 4.0 I 2.0 95% Codidence limi!r 1.4-3.7 I f -- !1 X,,, -caps 36 1.1-3-6 0-6-4.2 0.7-4.8 0.9-9.7 0.8-17.0 1 I0.7-6.0 10 7 7 6 J I ! THELA Chris. hrdrar culy st: .and cat bgnos from PC decade omitted Vith dc Nthoug ue reac hem C a d it i hued 3 It mu procedL pernasa mortality analyses nreollcnconsidcredsuspcct but PhIRsmay be of docl0r.C value if interpreted different from 100.~ especially if the ratios are very I &en b availabl Inthesccondstudy deathsentria for 1973wcreutilisedforacasr- service control study. Cases were the 537 dcaths in England and Wales in randomly selected from all causes of death except leukaemia 10 area hes males aged 15and above where the underlying cause ofdeaths was MlL. 1074 controls from death in males aged 15 and above were match caseswithin five year age groups. Table11showsconsistently incrc~sedrelative risks for the electrical occupations, the highat ! that th, phyici: 1. .Hitham S. M o n a h I y from leukcmu IU worten upcud IO rlcctnnl a d magnriu f i c I & . N n ~ ~ J L f cld982;3011 249. 1. Wnght W. Prier JW.Mack TAL LnJlrmv in votkcn expcard IO etccincal and magnriic Bel&. L l u r 1982; Y: 1160-61. risk being for telecommunications engineers. The data for one y a r (1973) used in this case-control study produced about as many deaths from AMI. to men in elmricd occupations as there were in the three years (1970-72) used in the proportional m:nIity analysis. This is primarily because direct examination of rl.. ..lth -As re taken. t,, Sovcm; Elackbc these, E 3 . 0 1 5o~f P~opulationCcnausa and Suneya Rrguiru Gencnl's d e n n u l supplement on orcuparionrlmonrlr9 1910-72. LDU~OHOM:O . 1978. 4. O f i n of Population Ccnsusa and Surury. ClauBcaiioa of mupaiioni 1970 London: HMSO, 1970. entries allowed use ofa more appropriate occupation clwii;: :::on. For example,. the 1970 classification used' clssified electrician's matcs and electrical welders with other occupational group not pnrursi: ascs, r ncgativ, 5. Kupprr LL. 3tc.%liclueAtJ, SymoruSt]. Mac B M . On ihr uiiliiy of propwiionil numaliiy amlysii. ]Chmn Du 1978.Jt: 15-22. 6. Wong0.DccoufleP. hkihodologial iuuainmlnngthe stmdardised macalily tilio and p r ~ p o n i ~ nrni io~nrlily raim In occupallond uudin. ] Osr .WJ 1982. 24: 299-304. identifiable as electrical occupations-which were thus omitted from the 1970-72 analysis. An error in the i n k of rhir classification probably resulted in some Post Ofice engineersbeing misclassificd. Finally, [he PbW analysis was limited to men under other 6 I and thc was th craccrt Y age 15. TABLE I-LEUKAEMIA MORTALITY IN ELECTRICAL OCCUPATIOSS. These two analyses rrinforcc the U.S. findinp.t*2Two ESGLASD A S 0 'SALES 1970-1971 (.MALES ACED 15-74) hypotheses to explain the leukaemia excess were suggcsied in the Lk;mmr P.oyal Infi Blwkburn 1 PAIR' (and no. of cascr) earlier rcports- exposure to electromagnetic fieldt (non-ioniring radiation) and exposure to chrmiuls and substances I .. ! in 'Prnmt i ymphoid Icukaemia clecrrical components or assembly. Unfortunately, there : ,!!e I Omparionr consistency between the studies in the degree of risk for dii1.s:nt electrical occup~tions,but the numbers arc small and different occupation classifications were used. Telephone linesmen and -- -1. 024: radio and ndar mechanics 025: installen ar.d repairmen telephoner 026: linermen, cable lolnlcrs 027: clectnciam 028: electrical and electronic litters 029 assemblers (electrical ..63(1) ..lU(16) 167(9) 125(Z) .. .. engineers show risks amongst the highest in three ofthcstudics, but only the 1970-72 proportional mortality study suggests that all electrical occupations combined have not an increased risk of icukaemia. It h?s been suggested that nomionking radhtion hu a short carcinogenic latency period7 Electrical occupations my be exposed to varying degrees ofsuch radiation, and mobility between occuparions may make data for specific occupations dimcult to interpret. Mcdicat Siaiisnm Vtri,ion. Omce oi Population Censuxa and Survey% London WC2B61P ,WC~IAELME.cDC)U;ALL SIR,- - mcthoc inicctcr tumour carcinc mrc c? remove predicr the for: circuh a large around quipmenr) 030: electrical engineen (so dcunbed) 128. telegraph radio operator 197: electrical enginten (proFeuional) 198: electronic engineen (professional) 73IJ) 112(1) .. .. 79(0 ,. .. .. Burd'on proporiioniit mondity of 111 Ensland and V a l a ~ I c aaged 15- 74 In 1970-12. t IC 0..8th ICVIYOO. UACTERIOLOGIGU DIAGNOSIS OF PFANSSIS SIR,-Dr Barrie(0ct. 9, p. 830)and Dr Diancse(Nov. 27, p. 1224) recommend active treatment early in pertussis, but if this policy is adopted it ought to be based, if possible, on a firm diagnosis not suspicion. Precise diagnosis is nearly always possibleearly in the discarcby culture of a pernaul swab. The result can be available in 3- I .!.i!s. which is not too long to wait before starting anttbiotics an; :cr potentially harmful drugs. Without this confirmtion ..ark treatment will mean much inappropriate prescribing by IimllY doctors. anorkc be rm, TOd: -Ofl"1-1 36hth I Chi,, 2 Ab& A, mr 91; 1 Wil Rc 6.G m r e% E.