Document rxaeK3JY4B8qBNQ8GN90NzKEV

88S90001S cc A STATISTICAL EVALUATION OF RESPIRATORY SYSTEM INDICATORS AMONG PIPE COVERERS 10-21-70 MGOtt I..N. TRODUCTi--IONhi __ This report presents statistical findings developed from an epidemiologic study of pipe coverers. The report does not include a review of literature on the subject or a medical interpretation of the results. In the location under study, the job of pipe coverer has existed since 1910. A list of 173 men who have held this job was prepared from company personnel records. Virtually all men who worked on the job for at least a year are included in the list, as well as most of the men who worked less than a year. As of January 1970, the status of the 173 men was as - follows: Still Working For Company 130 Active Pipe Coverers 94 No Longer Pipe Coverers 36 Quit or Released FromCompany 18 Retired TiS- 11 Deceased --14 lH- Within the identified exposed-to-risk population, the relationship between time-on- job and health indicators reflective of the well-being of respiratory function was investigated. The health indices examined in this study include (1) the mortality rate for cancer of the respiratory system (based on company insurance records, 1940-1970; (2) the incidence of morbidity episodes involving diseases of the respir atory system (based on company insurance records, September 1969-August 1970); and, (3) vitalometer measurements (derived from a multiphasic health screening program, 1967-1970). METHODOLOGY Selection Of Exposed-To-Risk Population And Controls Pipe coverers were identified through personnel Usts prepared on a monthly basis by the company. The personnel lists are ordered by department and job classifi cation within department and are retained as far back as the 1920's. However, only the January listings are retained beyond ten years. Since pipe coverers tend to remain on the job for a long period of time, this method is adequate for identifying the exposed-to-risk population. Two sets of controls were utilized in this study. The first set of controls consisted of the total plant population and the second consisted of pipe fitters. While the total t OOUJ 07143 ST0006589 - 2- plant population was selected fojrje nvenienceja_prqbability sample of the pipe fitter population was Tetfe^tedbliTs^tileile'Thetrhad jobs closely related to the pipe coverers except for exposure.to asbestos... The pipe fitters were identified by the same method as was used raTfcehTtfyTSrpipe coverers. Because there are . riseu*"-.r-'.'.*- rr. * : * many more p*ipe fit.*t.ersrrtha*n* cov*e rers, a thi.jr, ty percentsam*ep*le` was d^ rawa n b...y... terminal digit sampling of company identification numbers. zz riu*: zr. = ..rs.t;c,, zr.zf. *z-z- Method of Morbidity Analyais " '*T * ' * i -- ; '* A li ** ** * ; * .* tr- f . ^,C Trt 7 ' C * *' For the purpose of this ttudy, * morbidity episode is aa absence characterized by ' >'6* 9'k' ul>C s ( T w C 1 ' 1 s . , ' ' J . >! * (. the filing of a proper accident and sickness benefits claim covering a continuous . zr? in:.uoec it :.*.e v*.. a.- 77.;:: ii ir- t.c: . period of absence from work. The claim includes a physician's certification of the medical cause of the absence. In most cases, the morbidity episode must extend beyond seven, calends.; days before a record of the event is created. The program, as such, is available to hourly employees of the company. The expected - w r>v*r number of disability days shown in Tables 1 and 2 are based on a five year age i grouping of data on over 5, 000 hourly employees. Method of Vitalometer Analysis The company's multiphasic screening program, offered on a voluntary basis, calls for F. E.V. Total and F.E. V. 1 Sec measurements to be recorded for each partiei- ( f >r.ios -;-rc-rii:'. / .i.v. ' pant. A Collins Vitalometer produces the tracings which are digitized by a tech nician. For analysis purposes, the most positive of three repeated tracings for each individual is computerized. A regression equation was developed from the total screened population to adjust for height and age. Monthly comparison of measured results has shown that, over the three years of the program, consistent readings have been obtained. Using data generated through a multiphasic screening program has the advantage that neither the subject nor the technician is aware of uses to which the results might be put. Participation in thelheaith.inyentory program was about 67? during the first cycle of. the..program.-Jiy.combining first and second cycles, vitalometer readings were obtained for 101 men in the*pipe coverer population. Several selection factors which could bias somewhat the findings of this study should be noted. First, it was not feasible to follow up on the 18 employees who left the company; two of these men-were known to have left because of poor health. Secondly, a morbidity study covering a period two years following the first cycle of the multiphasic screening program revealed that participants in the program experience fewer illness-absence episodes than non-participants. The study did not enable us to determine the reasons for this difference. ib r`otSatSe*L*-:'*- T 'W ' w 07144 ST0006590 c t C -3- While the seme selection factors apply to the control populations, caution must be exerctaed in-interpreting -results because of these unknowns.. - --- - Method of Mortality Analysis ;u:-. tsoe*..:.. -iv-. The mortality analysis in based on copies of death certificates received by the com pany Group Insurance Department-as proof.of' death..: As .mentioned previously, individuals released from thercumpany,--excluding-retirees, will be lost to a mor- tality study based on.insurance records. The two control groups referred to in Table 6 were studied over a more, recent time period than the pipe coverers, even though the first, twenty .'yeara fallowing .initial, placementsn. the. job was not.accumu lated as partdoLthe. exposure-tcC-j:iik..years.for^pipe coverexs. . However, .since the mortality rate.due to-cano'ercof the Respiratory-system-has-been increasing.over the years, this comparison should error slightly on the conservative, side. The mortality rates ^or the.three groups were calculated on an age-adj usted basis. Smoking History . 7-.:.. _.-.i . A smoking history collected as part of the multiphasic screening program was not judged as satisfactory for, use in this study. The set of questions concerning smoking history has been restructured end appears to be producing results that can be useful ielthe-,future. The .lack: of. smoking history does.impose considerable', limitations on the conclusions that can be drawn from .the study..-------- RESULTS Table 1 shows that while no pipe fitter employment groups differ from the total plant in disability days due to respiratory disease, there are differences among the pipe coverers. The largest difference occurs among pipe coverers with 10 years or more of continuous employment on the job. These differences, however, are not fully reflected in total disability days. In Table 2, the number of episodes involving respiratory disease are compared. Based on a poisson approximation test, significant differences between observed and expected episodes were found for three employment groups among the pipe coverers and for no pipe fitter groups. However, the significant differences in the continuously employed group might be expected to carry over to the total group. Vitalometer Analysis The readings shown in Table 3 are height and age corrected. Only after ten years of employment do significant differences between corresponding groups of pipe coverers and fitters appear. The prior-to-employment group consists of men who worked at other jobs during the first cycle of the multiphasic screening pro gram and later became coverers or fitters. A non-linear regression equation fUsr ... t ***.' DOU 07145 I6S90001S c -4- c was developed for F.E.V. Total aad F.E.V. 1 Sec using years since first exposure as a pipe coverer for the independent variable. The regression lines, along with 'the scatter'plot of individual readings,. are shown in Figure X through Figure IV for both fitters and coverere*.............................. . Mortality Analysis ____ .... _ ... . . All causes of death .among .pipe gpvejtprs up to.k9.7Q^M listed in Table .5. These deaths are categorixed by interval between .initial employment.as a pipe coverer and death, and by length.of.employment a* a pipe coverer. An excess of total deaths and respiratory cancer deaths among pipe.coverers, as compared to two other groups, is indicated inTable 6..,,The number.of observations is quite small. In addition, two of the men dying from respiratory cancer also worked with lead arsenate. _ __ _ ............. ... .. _ .. SUMMARY The data presented in this study were derived only from ongoing routine functions of the company Medical Department. The investigation of vitalometer readings, morbidity episodes due to respiratory disease, and mortality due to respiratory cancer, indicated that pipe coverer's performed less well than did the comparison J groups. * There are two important limitations of the study aside from the size of the exposed- to-risk population. First, no smoking history.was obtained. Second, follow-back of individuals no longer with the company was not undertaken. I DOW 07146 c c 10-13-70 MGOtt Table 1. DISABILITY DAYS(1) PER PERSON PER YEAR AMONG PIPE FITTERS AND PIPE COVERERS ACCORDING TO LENGTH OF EMPLOYMENT (AGE CORRECTED). Employment as a... Pioe Fitter Pipe Fittera Disability Days Total Due To Number, of. Disability Davs ,, Respiratory Disease "Men^ Observed Expected'14 * 3Observed Expected Continuous <10 Years 10 Years or more .................. Both Continuous " and Non-ContinuousH) <10 Years 10 Year? or more siTi' - 5.V' ' ' 8.4 - - 34.>-- - 9. 3 ~- 12.6 :i; .. * - 58.3 6.7 8.5 67.5 * 12.1 12.2 '' 6.8 ' 1.7 , 0.8 1.4 1.4 1.9 1.6 1.9 ST0006592 Employment as a Pipe Coverer Continue us <10 Years 10 Years or more Both Continuous and Non-Continuous < 10 Years 10 Years or more -*> -* a ** Pipe Coverers r Number of Men Total Disabilitv Davs Observed Expected 57.0 33.7 8.0 13.8 8.8 13.0 70.1 57.0 12.6 11.9 8.5 12.7 JJLsability Days Due To Resoiratorv Disease Observed Expected 2.1 1.5 7.4 1.9 4.7 1.4 5.0 1.9 (1) Disability days include non-working days. The analysis period is fronr. September 1969 to September 1970. (Z) Number of men take on fractional values because some men may have retired or quit the company within the study period. (3) Expected values are calculated from the total plant experience and are age-corrected. (4) This category includes men who may have worked for several years as a fitter or coverer and then changed jobs within the company. ajL*; DOW 07147 c 10-13-70 MGOtt Table 2. DISABILITY EPISODES DUE TO RESPIRATORY DISEASE AMONG PIPE JITTERS AND'PIPE COVERERS. Number of Episodes -------------------- ---- ----- Pipe-Covere-r----- -- -- -Pipe Fitter-- Employment Observed Expected Observed Expected Continuous /|n Yiirfl _ - - OJ 3e 1 10 Years or more 14** 3.7 2 3.7 Both Continuous ind Non-Continuous < 10 Years 10 Years or more 16** 14*^ 6.4 6.2 5 5.3 5 7.3 Significant at .01 level. There were no statistical-differences between expected and observed episodes among pipe fitters. ST0006593 ./.- DOW 07148 ST0006594 c c 10-13-70 MGOtt ' Table 3. VITALOMETER KEaDENGS FOR PIPE 'COVERERS AND PIPE FITTERS BY EMPLOYMENT CATEGORY BASED ON HEALTH INVENTORIED--------- ----------:------------- ----------------- -------------------------- -------- Employment Catecorv .. * ' * -- - L - -- ------Pi pe -Fitteis F.E.V. F.E.V. F.E.V. F.E.V. Nbr. Total 1 See. Nbr. Total 1 Sec. Total 101 3.87 3.31 Ill 4.13 3.60 Prior to Employment ' 20 3. 90 3. 38 14 4.03 3.67 Continuous Employment <10 Years 21 4.17 3.58 24 4. 14 10 Years or more 30 . 3.76** 3.28 34 4. 12 3.62 3.51 Total Employment^------- -- -- -- ....--------- <10 Years 27 4. 10 3.61 27 10 Years or more 54 3.75** 3.23** 70 .. ---------- 4. 14 4. 15 3.63 3.57 (L> Years are calculated from date o first exposure regardless of the duration of employment. **Mean value for Pipe Coverers significantly different than mean value for Pipe Fitters at the .01 level (Student's -t Test) DOW 07149 cc Ejjv-xrt X. Jcqffev P\oT of FE,V, total rus/t/ios --f'tllTS_.by yti'fr S i*<L%..P.VjT Ltorrecfi'L). -. : _ j/j / .. ?Z?LPt .Ttii tjr..Ca.o i 3.0- F.E. W f a t a l ST0006595 F E.V. -Total DOUJ 07150 oas Tyvaa ` ` * HiSlj^u jj./ PI 0 I*, of.fi .V. !.S?C_raJi'i a s f 0Y 7I /3 1.0 -z. g~y~yf-aff iJiic. fi'rsf -f ALttL/>_<*S...a- finer (ij j ____X<;*Kf correg.t?J). / .._ - 1 -> 1 F*aue U. 5c aiiv Plot of f.V. I read -for fj pi'pt Covtriies by years ii'nce. e mjslcy mf n't a* a covered (<jjt Jl cor ^ ct <d) . J.o 6S90001S ............ * * * ' V 3 * 3 DOW 07151 Table S. cc CAUSES OF DEATH BY YEARS WORKED AS FIFE COVERER AND BY INTERVAL BETWEEN INITIAL EMPLOYMENT AS A FIFE COVERED AND DEATH. (BASED ON DEATHS REPORTED THROUGH SEPTEMBER 1972) Revised 11/72 MGOtt Interval Betveen Initial Employment As Floe Coverer And Death 0-9 Years 10 - 19 Years 20 - 29 Years 30 - 39 Years Yrs. Cause of Death Yrs. Cause of Death Yrs. Cause of Death frs. Cause of Death 2 Ca. Resp.* 14 "6" Myocardial __InfarctIon _ _ Suicide ~ * 29 _ _ if Ca. Resp. Post Op. 24 Ca. Resp. 22~ FaIl~At Work" l6~ -AortlcTib-Mltral_Valve_Disease 12" Ca. Pancreas 6 Coronary jOccluaion_ _ "l" a_;_ Respi^ _ <l" Myocardial In- ' farction (Fibrous adhes ions of apex of left lung) *** 31 To" 21" "7" Ca^ Respj. _ _ Ca^ Esophagus Arteriosclerotic _Ranal_Disease_ Ca^ R**P^.*i _ _ CO 001 cn VO ST0006597 *Had previously spent--1-1/2-years-lit-Pb Arsenate 19 years prior to death. **Kad previously spent 3 months in Fb Arsenate 29 years prior to death. ***Nad previously spent 1 year In Fb Arsenate 27 years prior to death 1 Mesothelioma not Included in above population--Died 1970--Worked grinding asbestos pipe cover to make "cement" for about 1 year (1945?). Table 6. OBSERVED DEATHS FOR FIFE COVERERS BEGINNING AT 20 YEARS AFTER INITIAL EMPLOYMENT VS. EXPECTED DEATHS BASED ON TOTAL PLANT POPULATION AND U.S. POPULATION MORTALITY RATES (ADJUSTED FOR AGE DIFFERENCES). Total Deaths Ca. Resp. Other Ca. Pipe Coverers* 1930 - 1969 13 6 2 Total Plant 1954 - 1969 5.9 .6 .9 U.S. Population 1966 7.6 .5 1.0 *Over 91 percent of the exposed-to-risk years occurred after 1953. DOUJ 07152 STQ006598 1 f c 8-30-73 MGOtt Man Nbr. 10333 23S33 01373 01433 01629 02063 02499 02839 03031 03226 04292 04743 05753 06777 18849 19626 01724 ` PZF C0VESEB DEATHS. --- ---- -- -- Nana ----- - - Died. . - /' Cauta . _ Months Exp. Crawford i-.. *---------- --- _ . J/72L . Accident- - - 233 Burov 6/70. ___ Suicide . '77 Brookar Burov . 8/45. 7/53" Ca.' Esophagus Ca. Lung 369 376 Cron 11435. Ca. Lung 18 Grahaa 11/66 ASHD 134 Kablbeck 3/49 Ca. Lung 29 Maynard Mclntoah . Paschick *... 10/70 _Ca. Pancraaa ..-.-3/69. - - Ca. Lung 10/58 Ca. Lung 151 83 V 350 Voods . 2/44 M.I. 75 Salva 7/72 Ca. Lung 328 Berrldga Molina /59 12/67 M.I. M.I. 164 6 Pack, A.L. 1/71 Ca. Lung 293 Kravcz 12/64 Heart 196 Deway, A.C.' ,3/69 M.I. 3 DOU 07153