Download: Executive Summary of the third project year

Subproject 4 is aimed at extending the CDR for the Techa River cohorts and to analyse health effects of TROC and ETRC.

Subproject 4 is aimed at achieving more precise estimates of radiogenic risks of both cancer and non-cancer effects in the Techa River cohorts based on data from extended follow-up and catchment area, as well as on improved dosimetric estimates. Also, the proposed task to carry out an assessment of radiogenic risk of cardio-vascular diseases, for the first time in the ETRC, (WP 4.3) is of considerable innovative significance.

WP4.1 Cause of Death Registry of the Techa River population

 Workpackage Leaders: Bernd Grosche (BfS), Alexander Akleev (URCRM)

The implementation of the present proposal for work package 4.1 is planned for 48 months. But, upon completion of the first 18-month phase, the project will be evaluated and decision will be made on further progress of work for the remaining 30 months.

The basic objective of WP4.1 is to extend the Cause of Death Registry (CDR) to include all seven raions along the Techa River, downstream of the Mayak facility, and to cover the time period 1950-2005. To date, the CDR covers the time period 1950-2001 and three of these seven raions. The CDR will give indispensable information for the envisaged risk analysis among TROC and ETRC members that will be used in the frames of WP4.2 and WP4.3. To this end, in a first step further causes of death will be included from two raions (Kataisky and Dalmatovsky raions in Kurgan oblast) in which a substantial part of TROC members were born and in which a substantial part of ETRC members live. This will result in coverage of almost 95% of TROC members and more than 80% of Techa River offspring. For the remaining two raions (Argayashsky and Sosnovsky rayons in Chelyabinsk oblast), which are less important in terms of the number of cohort members, it will be checked during the first 18 months to what extend information can be included. This special task is necessary, since the paths for data collection are not trivial. This is true for the entire catchment area, in particular for these two rayons. One could hardly consider the efforts that have to be made for collecting information from different sources/paths as "trivial". There is no all-Russia Death Registry. Thus, one has to use several sources to trace death certificates, among which the ZAGS archives and the Vital Statistics Office are the key ones. The search for cause of death information is rather an effort- and time-consuming procedure.

 Additionally, though the number of ETRC members is not very large in these raions, these are relocated persons who used to live in the higher reaches of the Techa before the evacuation, and who, consequently, received high doses. The information on causes of death for these persons is of great importance because these raions are included in the original catchment area in which residents have always been followed-up for disease incidence and vital status, and exposure doses have been reconstructed for them.

 Next to that, data on population denominators will be collected, measures for quality assurance will be taken, and it has to be decided based on which ICD version coding will be continued.

WP4.2 Health effects in the Techa River offspring cohort

 Workpackage Leaders: Alexander Akleev (URCRM), Per Hall (KI)

The implementation of the work package 4.2 is envisaged for 18 months, and is designed as a feasibility phase of a long-term study. The study is a logical development of our earlier projects implemented in the frameworks of Contracts # IC-15-CT96-0312 “Cancer Risk Among Individuals Exposed to Ionizing Radiation in the New Independent States Focusing on Methodological Considerations and Developments” and # FIGH-CT-1999-00007 “Late Health Effects Among Individuals Exposed to Ionizing Radiation in the Southern Urals’. The workpackage aims at assessment of radiogenic risk of malignant neoplasms (cancer and leukemia) for the first generation offspring of chronically exposed residents of the Techa riversides villages based on improved, in terms of quality and completeness, data on cancer incidence and mortality obtained through expansion of the study cohort, the follow-up period and the catchment area. The Techa River offspring cohort (TROC) studied in the frameworks of the latter contract comprises 7,897 individuals out of 11,155 potential members of the Chelyabinsk oblast offspring subcohort who were followed-up until January 1, 1996. The Chelyabinsk oblast offspring subcohort of the total Techa River offspring cohort includes persons born in the catchment area comprising 5 raions in Chelyabinsk oblast in which birth certificates were collected on a systematic basis. The members of the subcohort (numbering 3,258 persons) for whom information on dates and places of residence in the contaminated area was found to be missing or contradicting were not included in the analysis of late health effects in the project # FIGH-CT-1999-00007. During the proposed pilot study, the major efforts will be on increasing the size of the study cohort, extending the follow-up period up to January 1, 2000, and extending the catchment area. Cancer cases will be traced not only among offspring living in 5 raions of Chelyabinsk oblast (Kunashaksky, Krasnoarmeisky, Argayashsky, Sosnovsky, Kaslinsky), but also those who are resident in 2 raions of Kurgan oblast (Kataisky and Dalmatovsky) and Chelyabinsk-city for the period from 1 January 1950 through 1 January 2000.

WP4.3 Non-cancer late health effects in the extended Techa River cohort

 Workpackage Leaders: Per Hall (KI), Alexander Akleev (URCRM)

The work package, designated as a feasibility study, is scheduled for implementation within 18 months. A decision about the extension of the project will be made based on the outcomes of the 18-month effort. It is planned to assess radiogenic risk of cardio-vascular diseases as late non-cancer health effects in the ETRC.

The project objective is to analyze the mortality from cardio-vascular disorders for members (about 30,000) of the ETRC. We will study both overall mortality  from cardio-vascular disorders and specifically ischemic heart disease, myocardial infarction, cerebral infarction, and stroke We will extend the follow up to include the period 1950-2000 and have detailed information on vital status and cause of death from cardio-vascular disorders. Risk estimates will be based on the improved dose estimates given in TRDS-2000.