Document 0JLqgj63GYYGJN1bv3YgkZ8eM

EXCERPTS FROM A PROPOSAL FOR A JiSALTII STUDY OF VINYL CHLORIDE WORKERS presented uy TABERSUAW-CODi'ER ASSOCIATES, INC. March G, 1973 TCA, Inc., believes that an essential step in appraising the health implications of working in vinyl chloride production js to know the cause-specific mortality pattern. We therefore propose to conduct an epidemiological study of mortality in vinyl chloride workers,. The study would start with existing records and would follow workers to determine their current status. The objectives would be:: (1) to compare the mortality of individuals v;ho have worked in vinyl chloride plants with that of the general population, corrected for area, age and sex; (2) to compare mortality patterns within the population of vinyl chloride workers, based upon estimated occupational exposure;., and (3) to compare mortality among vinyl chloride workers with the mortality of other occupational groups which TCA, Inc. h? studied. Study design Although a more detailed study plan will be developed as ac tual plant populations and processes are defined, the following outline covers the essential elements. In each plant, the study population will consist of all workers who were employed for a least one year, beginning at the earliest date for v:hich records are available, and ending or, December 32, 1972. It lias been estimated that this group will consist of approximately *>,000 current employees. Our experience indicates that retirement:-, terminations and deaths before December 1972 will increase the total study population to about 7,500. For each person, age, date of employment, nature and duration of employment, and ethnic origin (if possible) will be determined. For those who have died, copies of the death certificates will be obtained, either from plant records or from the public health autho rities. These will be classified by cause of death, using the same rules as are used in national death statistics. Those who left employment will be traced to establish their present status, using post office notification, drivers license re cords, and other methods which i*n the past have enabled us to trace over ,96 percent of our study population. 1- - URL 02383 2- - In addition, as much information as poDsib.le on occupational exposure will be obtained fror.i plant management. At a minimum, we expect.to be able to classify job positions as involving cither high, medium or low exposure to vinyl chloride, both personal and plant data will be kept in the strictest confidence, and no indivi dual worker or plant will be identified by name in any analysis or tommunication about the data. Data collection A TCA, Inc. team will photograph all relevant personnel re cords at each plant. Involvement of plant personnel during the course of the study will be minimal, unless desired by local mana gement. The data collection team v/ill require a contact person at each plant through whom arrangements can be made and information channeled to local management. The only physical equipment requir ed at the plant is a worktable with a nearby electrical outlet. Our practice is to record data for active employees first and return the records to the files immediately, and then to examine the records for retirees, terminations and deceased employees. URL 02384 Data analysis Dependinq on the actual population size and the duration of follow-up activities, it appears probable that about 8CD to 1,000 deaths will occur i i\ the study group. The basic mortality analysis will begin with a calculation of the number of person years of observation contributed by the study group at each year of age and at each point in time during the study period, using a computer program prepared specifically for this pur pose. These data will be used together with the observed deaths at each age and each point in time to calculate mortality rates, v.*hich will be compared with the mortality to be expected in the comparable U. S. population, as obtained from national statistics. Techniques of this kind are well developed and have been used for some time in chronic disease studies. (See California Tumor Registry, Cancer Registration and Survival in California,California State Department of Public Health, l63.) The above analysis will be repeated for specific causes of death, paying particular attention to competing risks, or interac tion among different causes of death. In addition, analysis of general and causc-specific mortality will be repeated for subgroups of the study population identified as having high, medium and low exposure. The resulting mortality figures will be interpreted not only in light of their statistical significance, but for their relevance to known and suspected mecha nisms of action of vinyl chloride, and for their implications with respect to future studies of special areas and groups. -3- The validity of the conclusions reached from a study of this kind defend crucially on the competence with which data are collec ted and processed, and the appropriateness cf the comparative morta lity analysis. TCA, Inc. is uniquely qualified in both areas, the procedures and analysis proposed here have been tested successfully iri other industries end as a result, TCA, Inc., has a data bank of mortality profiles, which provide a realistic standard against which to compare vinyl chloride v.'orkcrs, and which furnish a second benen mark in addition to the general population statistics. TCA, Inc's, resources in occupational medicine and industrial hygiene further guarantee that the results of the mortality analysis will be evalua ted in relation to the current state of knov.'ledge in these fields. Tinetablc Exhibit I outlines the basic timetable of the major activities involved in the mortality study. The proposed study will require eight (G) months for completion. Once the plants are identified and approval is received, the records collection from, the plants will require approximately tv.'o months. Processing of the film, and classi fication oj. the records will require an additional month. At the sone time, feiiov.'-up procedures will be initiated. The search pro cess for the status of unknown workers ana the collection of death certificates for those who have died are the key follov.'-up activities and arc the most time consuming in the mortality study. These acti vities are also the ones most beyond our immediate control and it is for this reason that the study can not he successfully completed in a shorter time span. Every effort will be made to achieve a follow up level of 95V cr more and if this is accomplished earlier than an ticipated, TCA, Inc. will strive to supply the Manufacturing Chemists Association with a written report in less than eight rr.cnt/is. Pro gress retorts will be made cn a mutually agreeable schedule through the course of the contract. URL 02385 -4- nxnrniT i URL 02386 MORTALITY STUDY FLOV? CHART MAJOR ACTIVITIES MONTH 1. identify plants and tjct approval for visit 2. Visit plants anu film records ! j 3. Process and receive film j 4. Establish unit records and status determination 5. Search process for unknown workers 6. Obtain death certificates 7. Data analysis j I : I 0. Prepare and submit final report -5PROPODDD DUDGET Staff Personnel - Health Studies Unit Project Director, Statistician, Programmer, Occupational Physician ** Toxicologist, Industrial Hygienist. Clerical Assistants Total Staff Personnel Costs . $20,500 Direct Costs Records Collection Film Processing Death Certificate Fees Data Processing Printing, Forms and Supplies Total Direct Costs $ 3,300 2,0U0 3,000 500 ' $ 8,BOD Total Personnel and Direct Costs $29,380 Overhead, G and A, Profit Total Contract Costs $34,615 $03,995 Estimated Travel Costs* $ 7,350 Total Contract Price $71,345 Travel costs are based cn visits to 14 vinyl chloride end 10 polyvinyl chloride plants. This cost estimate will be ad justed once the actual plant populations are identified. URL 02387 \ V/V/73 I* L it t*vwU,i Itty ^ C.j&*X "Z*p*-^ <jz7 yWtnuMovt ftt*A*>A % \nx-U* tf. r^ aMxJLj - CaJ. ftni fi-vuoK^ia U.'iZA 6**L*L~j . &W/ aj^A MMf\ 't, AMAM^n^yt Jisu-*xAT -- -^n f n_7 rtf (h-a<^ c^ C /, 6 LTD ,t^l*'"T'? 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