Document 1QpaMLnd1Zb885Dj4wgVjqbXo

CorporatOeccupationMaeldicine 3M CenterB,uildin2g20-3W-05 St.PaulM,N 55144-1000 651-1347230Telel;Liune 6517339066Fax 2. An EpidemiologiMcortalitSytudyofEmployeesattheChemolitePlant Thisistheoriginarletrospectciovheortmortalirteyporto.femployeesattheChemolite Plant inCottage Grove, Minnesota conducted by Schuman and Mandel of the University ofMinnesota. Summary resultwsere citedby Ubel etal(seestudy# 1).A reviewof personnelrecordsindicatedtherewere 3688 workers employed foratleast6 months between 1947 and 1978. Vitalstatuswas ascertainedthrough 1978. The resultsof this analysisrevealedno significanftindings.The authorsreportedthata number of SNM'S, particularlfyorthe cancers,did exceed the nullvaluebut were not statistically significantT.hereforethey recommended continuedupdatingofthe vitalstatusofthis cohort.ItisImportantto notethatlineby lineabstractioonf work historycardswas not done inthe originalstudy;ratheronly the dateof firsetmployment atChemolite,lastdate of employment atChemolite,and periodofemployment inthe Chemical Divisionof the Chemolite plantwere abstracted.Individualjobs and departmentswere not abstracted. This originaldatafilewas subsequentlyused fortwo updates(seestudies4 3 and -44). However, inthe ongoing retrospectivceohortmortalitystudyof thisCottageGrove workforce (scheduledforcompletionby September 2000),theentirework historyrecord has been abstractedand willbe used toconstructan exposure matrixrelatedto perfluorooctanoiaccid. An tpidtmiolosic Mortality Study of Employees at the Chemolite Plant Leonard M. Schuman. M.D. Jack S. Mandel, 3- Epidemiology Associates February, 1980 An Epldemiologic hortality Study of Employees at the Chemolite Plant Introduction A retrospective cohort mortality study of employees at the Che.-nolite Plant in Cottage Grove, Minnesota was conducted. All employees who had worked at least six months at the Plant were included in the study. The basic objectives of the study were twofold: 1. To determine whether the mortality experience of employees at the Chemollte Plant was significantly different from that expected in a population group of this demosraphic composition. 2. To determine whether the mortality experience of employees in the Chemical Division of the Chemolite Plant was significantly different from that expected. ,Methods All employee records for all divisions of the Chemolit* Plant are stored in a central location (Personnel Office). The personnel recordkeeping system has been designed so that complete records have been maintained on all employees who ever worked at the Chemolite Plant. These records art also maintained for employees who transfer within the 3H Corporation. Thus. in constructing the study cohort it was assumed that a complete roster could be assembled of all employees who ever worked at the Chemolite Plant since its opening in 1947. A careful review of the personnel records Indicated that a total of 4218 had been employed at Chenclite for some period of time since 1947. of these, 3688 were employed for at least 6 months. This group comprised cohort for study. infeirmationwas abstracted from personnel record,. In many insr.Inces a number of records existed for a given employee and these records wt-re scor*d in different areas in the personnel office. Nevertheless, a]l sources of information were ascertained and the appropriate data abstracted. For each individual the following information was coded onto Fortran coding sheets: Employee number Name Address Telephone number Social security number Sex Blr'thdate Marital status Date of first employment at Chemolite Date of last employment at Chemolite Period of employment in the Chemical Division Status (current, retired, deceased, disabled, laidoff, transferred. terminated, reason not stated and returned to school) Date of death (if noted on record) Area transferred to (if noted on record) For each of the 3688 employees, two computer cards were punched with the information mentioned above. A computer tape listing the name, social security number and birchdate of but Elle! current employees was developed and sent to the Social seciirity Administration (SSA) to ascertain those individuals who had died during the period of study (1947 - 1978). A total of 180 deaths were ascertained from SSA records. For each deach the state of last residence. the state of last employ-ment, or the ,tate from which the benefit was filed along with the date of death was listed. This Information was used to obtain a copy of the death certificate for each decedent. Unfortunately, since the most vital piece of Information - state in which the death occurred - was not provided by the SSA, acquisition for all death certificates was a formidable task. For those deaths for which a death certificate was not available from the state of last residence, the state of last employment, or the state from which the benefit was filed, a search was made in Minnesota using the Minnesota Health Department's camulative microfiche death index 1962 - 1978 and the death records prior to 1962. Information (name, social security number, birthdate, date of death) on all deaths for which the death certificate was not acquired by..any of the above mentioned methods was sent to the Wisconsin Health Department to determine If a death certificate was on file in their records. Utilizing these procedures. 168 of the 180 (93.3%) death certificates were acquired. Information on the remaining twelve with a request for a copy of the death certificate was sent to every state health department except Minnesota, Wisconsin and New York. Minnesota and Wisconsin were excluded since their records had already been reviewed. New York was excluded since they require the borough In which the death occurred to i.ec,.orrotihne death certificate. However, If any of the twelve death cercific-iresremain outstandingafter a search by all other state health deparcments, then an attempt will be made to access New York vital records. The death certificates were coded by a professional nosologist according to the InternationalClassificationof Diseases (I.C.D.), Eighth Revision. All information In the cause of death section of the death certiflcstt was coded. This included the underlying cause of death, immediatt cause of death, tonditions related to the immediate cause of death (referred to on the death certificate as "as a consequence of" or "due to"), and other significant conditions. These codes along with the Individual's natneand social security number (to facilitate linking these data to the main file) were transferred onto Fortran coding sheets and keypunched. In addition to Identifying the deaths. SSA reported that for 485 members of the study cohort no benefits were currently being paid. This meant that SsA could not emphatically state whether these individuals were dead or aiive. However, published reports (see for example Wang, H. and Mac-Mahon, D. J. Occup. Med., 21, 745, 1979) have stated that the aseertainment of mortality by SSA Is virtually complete and that additional follow up on individuals for whom no information is available from SSA records is unnectessary. Nevertheless, In order to be absolutely certain that all deaths were ascertained, every effort was made through extensive tracing efforts tn 1,,terminethe current stattinof these 485 unaccounte-i for study menher... The status of virtually all of these people was determined in this way. Method of Analysis The method of analysis is based on a comparison of the observed to expected death rates specific for cause. age. time, sex and race. The is described in detail in Monson, R., Analysis of relative survival ind prcji)ortionalmortality. Comp. Riomed. Res., 7. 325-332, 1974. The output from this analysis provides the observed and expected number of deikthas the ratto of observed to expected (SHR), and the upper and lower 952 confidence limits. The 95% confidence limits art defined as follows: Lower Limit - LL Upper Limit - UL (I - 1/9,9- 1.96 13kl-1-4)y) /E rl-l(-Vl)) 3) - 1/9(&l) + 1.96/3 /E W'nere 0 - observed number of deaths E - expected number of deaths Restilts Records on 4,218 employees were reviewed and abstracted (Table 1). Only those who worked at Chemelite for six or more months (3,688) were included in the mortality followup. Ln the 180 known deaths, 168 (93.3%) death certlficates were obtained. There were 159 male deaths and 21famale deaths. Table 2 presents the results for Chemolite Plant male employees. overall, the number of deaths (149) was significantly less than expected (208.3). This "deficit" was primarily due to the lower than expected number of deaths from diseases of the circulatory system and all external causes of death. The observed-to-expected racto for cancer deaths was 1.0. indicating no disparity between the number of deaths observed and the number expected. The only O/E ratios which exceeded 1.0 were for deaths due to asthma (2.8) and motor vehicle accidents (1.1). However, neither even approached statlstical significance. 1. EpidemiologicMortallty Study of Chemollte Plant July.'1978 - December, 1979 itecordsAbstracted Number Studled Number of Deaths Death Certiflcates Analyzed 4.218 3,688 180 (4.9%) 168 1-jhlc 2. Results of Cause-Specific Mortality Analysis Males. Chemolite Plant (> 6 months) Ca -use- of Death 140 - Malignant Neoplasms 000 - All Infective Tuberculosis and Parasitic Diseases 240 - Allergic. Endocrine, Metab., Nutr. Diseases r)iabetes Nellitus 320 - All Diseases of Nervous Sys. & Sense Organs 390 - All Diseases of Circulatory System Chronic Rheumatic Heart Disease Arteriosclerotic H.D.9 Incl. CED All Vascular Lesions of CNS 460 All Respiratory Diseases All Pneumonia Emphysema Asthma 520 All Diseases of Digestive System All Gastric and Duodenal Ulcer Cirrhosis of Liver 800 All External Causes of Death All Accidents moto"r Vehicle Accidents Suicide All Causes of Death 0 E O/E UL 37 37.1 1.0 .7 1.3 1 2.5 1 1.3 .4 .0 2.3 .8 .0 4.5 3 3.4 2 2.8 .9 .2 2.6 .7 .1 2.6 2 2.4 .9 .1 3.1 64 83.0 1 2.6 50 61.4 4 8.5 .8 .6 @c 1.0 .4 .0 2.2 .8 .6 1.1 .5 .1 1.2 6 8.9 .7 .3 1.5 2 3.5 .6 .1 2.1 1 2.0 .5 .0 2.8 1 .4 2.8 .0 15.8 7 12.4 1 1.3 4 7.6 .6 .2 1.2 .8 .0 IA.4 .5 .1 1.4 29 49.0 .6 .4 .8 24 33.4 .7 .4 1.0 20 18.3 1.1 .6 1.6 5 10.1 .5 .2 1.2 149 208.3 .7 .6 .8 Results of Cause-Speclfic Mortality Analysis Males. Chemollte Plant (>,6 months) Cancer Cause of Death All Malignant Neoplasms cancer of Digestive Organs Peritoneum 150 - Cancer of Esophagus 151 - Cancer of Stomach 153 - Cancer of Large Intestine 154 - Cancer of Rectum 157 - Cancer of Pancreas Cancer of Respiratory System 161 - Cancer of Lary= 162 - All Cancer of Lung (Prim. & Sec.) 172 - Cancer of Skin 185 - Cancer of Prostate 186 - Cancer of Testis 189 - Cancer of Kidney 191 - Cancer of Brain & Other CNS All Lymphopoietic Cancer 201 - Hodgkins Disease 208 - Cancer of Lymphatic Tissue 0 E o/r 1.1. 37 37.1 1.0 9 9.0 1.0 1 .8 1.3 1 1.6 .6 3 2.9 1.1 1 1.0 1.0 2 1.9 1.1 9 12.5 .7 1 .5 1.9 8 11.8 .7 1 1.1 .9 2 1.0 2.0 1 .7 1.5 1 1.0 1.0 2 1.9 1.1 4 5.0 .8 2 1.1 1.9 2 .9 2.2 .7 1.3 .5 1.9 .0 7.1* .0 3.5 .2 3.1 .0 5.6 .1 3.9 .3 1.4 .0 10.7 .3 1.3 .0 5.0 .2 7.3 .0 8.3 .0 5.6 .1 3.9 .2 2.0 .2 6.8 .3 8.0 158 other Digestive 1 195 111 Defined Sites 1 199 Malig. Neopl. Without Speelf. of Site 6 in 3. the 37 cancer deaths are distributed by site. None of th,eresults were significant. Tables 4 and 5 present results for deaths among men who were employed for 8C least six months In the Chemical Division Of the Chemolite Plant. overall, the observed numbe.ro.f death& (55) was less than expected (66.1). This was mainly the result of the lower than expected number of deaths from diseases of the circulatory system. The highest 0/t ratio, 9.2, occurred for deaths due to asthma. However, this ratios based on only a single death in the 21 year study period. was not statistically significant. A total of 13 cancer deaths occurred among the Chemical Division male employees. This was approximately the number expected (11.2). Although the O/E ratio for a n=ber of cancer sites exceeded one, nonewere statistically significant. A distribution of the 19 observed deaths among female employees is presented In Table 6. No major departure& from expected were noted In these results. Discussion The lower than expected mortality from all causes la often found in seudies of occupational cohorts. This refleCES "the healthy worker" effect. Generally. individuals who are disabled or chronically ill are excluded from certainwork situations.particularly those requiring considerable physical activity. Thus,employea cohorts compared to the general Population generally have more favorable mortality outcomes, particularly for younger employees. 7o compensate for this effect the data could be reviewed with an O/E ratio of less than 1, (perhaps .9 is appropriate) considered equivalent to no differencebetween observed and expected deaths. Reviewing the data with 'Table 4- Results of Cause Specific Mortality Analysis Males. Chemical Division (>,6Months) Cause of Death 140 - Malignanc Neoplasms 240 - Allergic. Endocrine, Metab., Nutr. Diseases Diabetes Mellitus 320 - All Diseases of Her-vous Sys. i Sense Organs 390 - All Dise4ges of Circulatory System Arteriosclerotic H.D. Incl. CHD 460 - All Respiratory Diseases All Pne=onla Asthma 520 - All Diseases of Digestive System All Ga$tric and Duodenal Ulcer Cirrhosis of Liver Boo kll External Causes of Death All Accidents Motor Vehicle Accidents Suicide All Causes of Death 0 E O/E LL UL 13 11.2 1.2 .6 1.9 2 1.1 1.9 .2 6.8 1 .9 1.1 .0 6.5 1 .8 1.3 .0 7.0 16 24.3 14 17.9 .7 .4 1.1 .9 .4 1.3 4 2.7 1.5 .4 3.9 2 1.1 1.9 .2 6.7 1 .1 9.2 .1 51.1 5 3.9 1.3 .4 3.0 1 .4 2.6 .0 14.5 3 2.4 1.3 .3 3.7 14 19.1 .8 .4 1.3 12 12.5 1.0 .5 1.7 9 7.0 1.3 .6 2.4 2 3.6 .6 .1 2.0 55 66.1 .8 .6 1.1 -rlble 5. Results Of Cause-Specific Mortality Analysis Males. Chemical Divisioe (>,6Months) Cancer Cause of Death 140 - Malignant Neoplasms Cancer of Di&estive Organs & Peritoneum Cancer of Esophagus Cancer of Large Intestine Cancer of Pancreas Cancer of Respiratory System Cancer of Larynx Cancer of Lung (Prim. & Sec.) Cancer of Skin Cancer of Prostate Cancer of Testis 0 E O/E LL UL 13 11.2 1.2 .6 1.9 3 2.6 1.1 .2 3.3 1 .2 4.4 .1 24.5 1 .9 1.2 .0 6.6 1 .6 1.8 .0 10.2 4 3.7 1.1 .3 2.8 1 .2 6.7 .1 37.3 3 3.5 .9 .2 2.5 1 .4 2.7 .0 15.1 1 .3 3.9 .1 21.8 1 .3 4.0 .1 22.1 199 Mali&. Neopl. Without Specification of Site - 3 Table 6. Specific Causes of Death Females. Chemollte Plant (J6 months) 0 E 009 Diarrheal disease 1 .4 162 Hall&. neopl. of lung 1 1 272 Kalil. neopl. of skin 1 -2 174 K&118. neopl. of breast 2 2.5 183 Mall&. neopl. of ovary 191 MallS. neopl. of bratit 402 Hypertensive N.D. 1 .8 1 .4 I 410 Acute M.I. 412 Chronic Ischemic H.D. 1 7.5 44 @ 427 Symptomatic H.D. 2 472 Influenza vith other reap. manlfestations I I 493 Asthma I 812 Car accident vith other car 819 Car &cc. of unspecified nature- 1.5 1 Total 19 a null hypothesis of .9 would not substantially alter the conclusions. Deaths for U.S. white males and females were used to derive expected values. A more appropriate comparison population might have been deaths for the counties In which the employees resided, namely Dakota. Ramsey and Washington In Minnesota and Pierce and St. Croix in Wisconsin. There are two major problems with using data from these counties to derive expected values. First, age-sr-x-race and cause specific death rates are not available by county for periods back to the late 1940's. Second, if such rates could be derived from the basic data, the relatively small z)opulationbases would result In highly unstable rates. One strategy for considering geographic differencesln itortalityis to examine available data for the counties of Interest In relation to the United States rates. For cancer, age adjusted death rates are available by county for the period 1950-69. These data were examined for the above mentioned counties and compared to the rates for the United States. For those cancer site& where the rate was based on an average of at least one death per year the only notable difference between the rates for the 5 counties and the U.S.,,was for lung cancer where the age-adjusted ra-.tewas appreciably lower In 4 of the 5 counties than in the U.S. as a whole (the rate for Ramsey county approximated the U.S. rate). The O/Z ratio for lung cancer was less than 1.0. This is an underestimate of the SM;t If calculated using county rates. However, re-calculating the S,4R using county data to derive expected values would probably result in an SKR of about 1.5. which would not be statistically xignltlcant. AlthouRh the results of this analysis revealed no significant f tndings. numberof SMR'S, particu laTlY for the cancers, did exceed one. Thus, continued surveillance for mortality Is warranted. As of the writing,Of this report (February 26. 1980) Information on the 12 deceased study members whose death certificates %Pere not available at the time the data was analyzed is as follows: 2 died In service. one In Vietnam and one In Korea 4 died from cardiovascular disease 2 died from cancer 1 died from Injuries sustained In an airplane crash 3 cause of death unknown (2 of these deaths occurred among employees who worked at Chemolite for less than 6 months) From the above distribution of deathsg it Is obvious that the addition of these deaths to the analyses presented in this report does not alter the conclusions.