Role of radiation and non-radiation factors on the development of coronary heart disease in the Chornobyl clean-up workers: epidemiological study results

Probl Radiac Med Radiobiol. 2014 Sep;19:67-79.
[Article in En, Ukrainian]

Abstract
in En , Ukrainian

Objective. The objective of this study was to establish the risks for coronary heart disease in the Chornobyl clean-up workers with regard to a whole-body external radiation dose and non-radiation (biological, social-and-hygienic and behavioral) factors. Materials and methods. Risk-analysis was based on the cohort of the Chornobyl male clean-up workers 1986-1987 (8,625 men, including 3,623 with available whole-body external doses). Data of clinical-and-epidemiological registry, National Research Centre for Radiation Medicine were used for 1992-2013 monitoring period. We used the internal control group with radiation doses less than 0.05 Gy. Results. Statistically significant radiation risks in the Chornobyl clean-up workers were established for the coronary heart disease at doses 0.15-0.249 Gy, 0.25-0.99 Gy, 1 Gy and more (dose group 0.15-0.249 Gy RRY=1.9 (1.2; 3.1), ERR=4.6 (1.5; 14.9) Gy-1, EAR=64.2 cases per 1000 person-years, Gy); among exposed people aged 40 years and older - at doses 0.5-0.99 Gy (RRY=1.4 (1.05; 1.81), ERR=0.5 (0.03; 1.1) Gy-1, EAR=30.5 cases per 1000 person-years, Gy). Statistically significant risks for the disease under consideration were also identified with regard to non-radiation factors (smoking, improper physical training, adverse working conditions, diseases etc; age and psychoemotional overstrain were of a particular impact). Non-radiation factors are at most responsible for development of coronary heart disease. For this reason the control of potential confounding factors is required to assess the effect of the radiation factor both at a stage of comparison groups selection and analysis using the Mantel-Haenszel method.

Meta. Vyznachennja ryzykiv rozvytku ishemichnoi' hvoroby sercja sered uchasnykiv likvidacii' naslidkiv avarii' (ULNA) na ChAES z urahuvannjam dozy zovnishn'ogo oprominennja vs'ogo tila, a takozh neradiacijnyh faktoriv (biologichnyh, social'no-gigijenichnyh, povedinkovyh). Materialy j metody. Za danymy kliniko-epidemiologichnogo rejestru NNCRM provedeno ryzykanaliz na kogorti ULNA 1986–1987 r. cholovichoi' stati (8625 osib, u t.ch. 3623 osib z dozamy zovnishn'ogo oprominennja vs'ogo tila). Period monitoryngu 1992–2013 rr. Vykorystovuvalasja vnutrishnja kontrol'na grupa z dozamy menshe 0,05 Gr. Rezul'taty. V ULNA, oprominenyh u vici do 40 rokiv, vstanovleni statystychno dostovirni radiacijni ryzyky rozvytku ishemichnoi' hvoroby sercja pry dozah 0,15–0,249; 0,25–0,99; 1 Gr i bil'she (v dozovij grupi 0,15–0,249 Gr RRY=1,9 (1,2; 3,1), ERR=4,6 (1,5; 14,9) Gr-1, EAR=64,2 vypadkiv na 1 000 ljudyno-rokiv, Gr); u oprominenyh u vici 40 rokiv i starshe – pry dozah 0,5–0,99 Gr (RRY=1,4 (1,05; 1,81), ERR=0,5 (0,03; 1,1) Gr-1, EAR=30,5 vypadkiv na 1 000 ljudyno-rokiv, Gr). Vyznacheni takozh statystychno dostovirni ryzyky rozvytku doslidzhuvanoi' patologii' z urahuvannjam neradiacijnyh faktoriv – palinnja, neracional'nyh fizychnyh navantazhen', nespryjatlyvyh umov praci, najavnyh hvorob i in., prychomu najbil'sh vplyvovymy je vik i psyhoemocijna perenapruga. Ryzyk rozvytku ishemichnoi' hvoroby sercja u vyznachal'nij miri zumovlenyj neradiacijnymy faktoramy. Tomu dlja ocinky vplyvu same radiacijnogo faktora potriben kontrol' potencijnyh faktoriv zmishuvannja jak na etapi formuvannja grup porivnjannja, tak i na etapi analizu z vykorystannjam, napryklad, metodu Mantel-Hanzela.

Keywords: Chornobyl accident; Chornobyl clean-up workers; coronary heart disease; radiation and non-radiation factors; registries; risk.