Document 2jVQJojJXDed5LQJXDGOoD0zN

OCCUPATIONAL ASBESTOS EXPOSURE AND MESOTHELIOMA IN CONNECTICUT Teta, Mary Jane; Lewinsohn, Hilton C.; Meigs, J. Wister Connecticut Cancer Epidemiology Unit Yale School of Epidemiology and Public Health New Haven, CT USA 06510 Vidone, Romeo A. St. Raphael's Hospital New Haven, CT USA 06511 The present study has examined all cases of primary malignant meso thelioma (201) and primary malignant pleural tumors other than mesothelioma (19) recorded in the Connecticut Tumor Registry (CTR) and diagnosed from 1955 to 1977. The authors have attempted to determine the role of occupational and environmental exposure to asbestos and to consider possible diagnostic errors through review of available histo logic materials. Medical, demographic, and occupational data have been collected for patients and for their spouses, from hospital records, death certificates, city directories. Similar information has been gathered for a random sample (604) of Connecticut decedents (1955-1975) ages 20 to 98 years. Histologic material along with gross autopsy and clinical reports were submitted for review. In preliminary results of the first 138 cases examined, a diagnosis of mesothelioma was favored in 73.2% of the cases and judged to lack characteristics of mesothelioma in 6.5%. Results were inconclusive in the remaining cases. Although 3 cases were found to have been employed at one time by an asbestos products manufacturer with first hire in the 1920's and 1930's, there was no evidence of a residential risk to persons living in the vicinity of the plant. Significant excess risk was observed for 'car penters and cabinet makers' (RR= 2.25; p<.05), 'plumbers and pipefit ters' (RR= 3.87; p<.05), and those 'ever employed' in the rubber industry (RR= 5.08; p< .01). The statewide proportion of cases occupa tionally exposed was 85%. A monotonic increase in risk associated with higher levels of asbestos exposure was suggested, particularly for the 70-98 year old age group. A x2 test for trend was highly significant overall (p< .0005) and for the oldest age group (p< .0001). Incomplete employment histories and the potential for random misclassification of exposure status limit our ability to draw firm conclusions. Further research including personal interviews of cases and controls and se lected clinical examination might help to clarify these findings and suggest additional risk factors both personal and environmental, which may account for those cases for whom there exists no documented evidence of asbestos exposure. A0 1 988 PLAINTIFF'S EXHIBIT QwMUcuJf Occupational Asbestos Exposure and Mesothelioma in Connecticut Teta, Mary Jane; Lewinsohn, Hilton C.; Vidone, Romeo A.; Meigs, J. Wister Research performed by the Connecticut Cancer Epidemiology Unit using data provided by the Connecticut Tumor Registry and by the Division of Health Statistics of the Connecticut State Department of Health Services. Pathologic review conducted at St. Raphael's Hospital, Department of Pathology, New Haven, Connecticut. Presenter: Mary Jane Teta, MPH International Conference on Occupational Lung Disease March 24-27, 1982 Chicago; Illinois AO 19 8 0 The present study has examined all cases of primary malignant mesothelioma and pleural tumors other than mesothelioma recorded in the Connecticut Tumor Registry (CTR) diagnosed over the 23 years from 1955 to 1977- We've attempted to determine the role of occupational and environmental exposure to asbestos and to consider possible diagnostic errors through review of available histologic materials. (Slide 1) Medical, demographic, and occupational data have been collected for 201 patients with mesothelioma, 19 patients with pleural tumors other than mesothelioma, and for their respective spouses, from hospital records, death certificates, and city directories. Similar information has been gathered for a random sample (604) of Connecticut dece dents (1955-1975) aged 20 to 98 years. (Slide 2) City directories were searched for The s*. job title, specific employer, and industry, for cases, controls, and case spouses.1^, I, 10, 20, 25, 30, 40, and 50 years prior to date of diagnosis, death, or until the subject was less than 20 years old. Geographic risk pattens were examined using the 1966 Labor Market Area (IMA) divisions of Connecticut developed by the State Department of Labor. (Slide 3) Histologic material along with gross autopsy and clinical reports for 174 cases with available slides were submitted-te a ConnactiVut pathologlot for-re viam. No personal identifiers or occupational data was Included. In preliminary results of the first 138 cases examined, the pathologist favored a diagnosis of mesothelioma in 73.2% of the cases; judged the case to lack characteristics of mesothelioma in 6.5%; and was unable to make a diagnosis in the remaining cases. None of the 19 pleural tumors other than mesothelioma are included in this tabulation. Search of occupational data for indicators of exposure at work showed that 3 cases were employed for varying time periods beginning as early as the 1920's by an asbestos products manufacturer. However, CD searches showed that one of these sub jects also held a number of other jobs with possible asbestos exposure. (Slide 4) In a case-control risk analysis, the sample was restricted to males over 30 years of age at death or diagnosis, who were bom after 1875 (N=611; 147^ casesj ^ ^ AO 199i Page 2 464 controls). When the subjects' occupation titles were used for comparison, signi ficant excess risk was observed for the category 'carpenters and cabinet makers' (RR= 2.25; p<.05) and 'plumbers and pipefitters' (RR= 3.87; pZ.05). (Slide 5) A parallel comparison using industry title showed a significant association with the rubber industry (RR= 5.08; p.01), which was particularly striking when limited to subjects 70 to 89 years of age at death or diagnosis (KR= 16.97; pZ.005). Further efforts were made to classify study subjects in terms of probability of occupational asbestos exposure. Based on available occupational titles and without knowledge of the disease status of any individual, a subset of jobs and another sub set of industries was selected for which exposure to asbestos was considered either 'possible' or 'likely'. For all others, exposure was considered to be 'unlikely'. This procedure allowed us to examine the proportions of cases with asbestos exposure and the relative odds of disease across the various Connecticut Labor Market Areas. (Slide 6) These regions surround Connecticut's large urban centers or are areas of recent rapid expansion. On the basis of job title alone there is little variation by Labor Market Area in the proportion of cases with 'possible' or 'likely' exposure. The overall proportion was 67%. (Slide 7) On the basis of industry title, the overall proportion was 66%; however, one of the large industrialized regions had an approximate 4-fold risk. Using expo sure either through job or industry as a criterion, the overall proportions exposed became 85% for cases, 78% for controls, yielding an age-adjusted relative risk of 1.57, p Z .05. In an attempt to provide an indicator of the duration and severity of occupational asbestos exposure for both cases and controls, a scoring procedure was developed. If for a given time period a job title in the 'likely' category could be documented from DC or CD for an individual, a score of '2' was assigned. A job title from the 'possible' group was given a score of '1', from the 'unlikely' subset a score 'O'. These scores AO 1992 Page 3 were summed across all available time periods for which employment information was available, and each study subject was assigned a final single job index of exposure. (Slide 8) This crude measure allowed us to quantify the risk factor into ordered levels of exposure and examine a dose-response relationship. A monotonic increase in risk associated with higher levels of occupational asbestos exposure is suggested, particularly for the oldest age group. This is consistent with the long latency for mesothelioma as previously reported in the literature. We explored the question of a possible residential risk to persons living in the vicinity of an asbestos plant. We first excluded all the occupationally exposed cases and controls residing in the LMA in which the plant was located. After exclu sion of all subjects with 'possible' or 'likely' asbestos exposure, using either job title or industry or both, there remained 9.5% of all mesothelioma cases and 9.2% of all controls in that I21A. This result fails to support the hypothesis of a signi ficant residential risk. Incomplete employment histories and the potential for random misclassification of exposure status limit our ability to draw firm conclusions. This is particularly re levant with regard to the 'true' proportion occupationally exposed and the 'true' magnitude of the relative risk, which is likely to be higher than our findings in dicate. The significant risk associated with the older age groups may in fact be an artifact, attributable to 'time since first exposure', for which we have insuffi cient reliable information for study subjects overall. The association with the rubber industry requires additional exploration because of the lack of specific information regarding the many aspects of manufacturing pro cesses lumped into this broad category. Further research including personal interviews of cases and controls and selected clinical examination might help to clarify these findings and suggest additional risk AO ! 99 3 Page 4 factors both personal and environmental, which may account for those cases for whom there exists no documented evidence of asbestos exposure. Mesothelioma Cases and Pleural Tumors other than Mesothelioma Reported to the Connecticut Tumor Registry, 1955-1977 Diagnosis Pleural mesothelioma Peritoneal mesothelioma Mesothelioma at other or at unknown sites Pleural tumors other than mesothelioma Total No. 137 29 35 201 19 220 AO 1 9 9b SOURCES OF OCCUPATIONAL DATA FOR CASES, CONTROLS, CASE SPOUSES Death Certificates City Directories 1, 10, 20, 25, 30, 40, 50 years from death or diagnosis. A0 1 996 D ia g n o s tic C la s s ific a tio n o f C o n n e cticu t Tumor R e g is try R eported P re lim in a ry re s u lts based on 138 o f 174 cases w ith a v a ila b le m a te ria l. 0V cn CO NO (--1 O aH (U (0 CJ 25 3 3 V 3 CO 3 0 H O H H- H W ft O CO O co Hi 3 O' CO O' 0 H- O 3 0) H- <U ft O *: O' O' O' S' 0 3 co t--1 0 XJ H H l-> ft H- ft H- 0 3* 53 3 3 0 3 0o 0 3 H ft CO CO OJ HO3 0rt 0 ft 3 0) CO S' O' CD O 0 HM 0 ft H- H- CO S' o 0 (D 3 3 00 l- cu 0) 0 8 H- 0 co o (D Hi !> 1 Pi s O 3 0t-> > H- (O 3P> 3 <U S ft 3 i0 O ft 00 NO NO O CN 00 <U NO VO 0) H- (t) O O CO Hi CO u> 00 00 VO NO O *3 0 0) ft ft 3* O SH*' H H- O Q 1 cu JO (0 <H- VO cn ui l H O O cn O' a O OO cn -J >fa> CO U1 NO 3 i-3 H OO ft P3 H ft 0 Hi VO vl -JM AO 1 99.7 Mesothelioma Cases Ever Employed in Jobs Associated with Asbestos Exposure by Connecticut Labor Market Area LMA1 LMA2 LMA3 LMA4 LMA5 LMA6 LMA7 LMA8 Total No. ever exposed 21 1 17 14 4 6 8 26 97 P <.01 Percent 70 25 65 74 67 60 62 72 67 RR 1.27 .36 2.16 2.49 2.89 1.61 1.02 1.66 1.63' Mesothelioma Cases Ever Employed in Industries Associated with Asbestos Exposure by Connecticut Labor Market Area No. ever exposed Percent RR LMA1 26 90 3.75 LMA2 1 33 .83 LMA3 15 58 1.43 LMA4 13 76 1.47 LMA5 5 100 + IMA6 4 50 1.17 LMA7 7 54 .40 LMA8 17 53 1.13 Total 88 66 1.36 *p < .10 + odds ratio not computed because of zero cells AO 1999 RELATIVE RISK O -- ro oj 4^ m <D DOSE-RESPONSE RELATIONSHIP OF MESOTHELIOMA AND OCCUPATIONAL ASBESTOS EXPOSURE BY AGE GROt JOB EXPOSURE SCORE