Hospitalizations Among Chernobyl-Exposed Immigrants to the Negev of Israel, 1992-2017: A Historical Follow-Up Study

Abstract

On April 26th, 1986 the nuclear reactor at Chernobyl, Ukraine exploded, causing the worst radiation disaster in history. The aim was to estimate hospitalization rates among exposed civilians who later immigrated to Israel. We conducted a historical follow-up study, among persons exposed to Chernobyl (n = 1128) using linked hospitalization records from Soroka University Medical Center (SUMC), compared with immigrants from other areas of the Former Soviet Union (FSU) (n = 11,574), immigrants not from FSU (n = 11,742) and native-born Israelis (n = 8351), matched on age and gender (N = 32,795). Hospitalizations for specific ICD-10 coded diagnostic groups were analyzed by exposure and comparison groups by gender and age at accident. In addition, the rate of hospitalization, and the duration of hospital days and the number of hospitalizations for these selected diagnostic groups was also calculated. Hospitalizations for specific ICD-10 coded diagnostic groups and for any hospitalization in these diagnostic groups in general were analyzed by exposure and comparison groups and by covariates (gender and age at accident). The rate of any hospitalization for the selected diagnostic groups was elevated in the low exposure Chernobyl group (51.1%), which was significantly higher than the immigrant (41.6%) and the Israel-born comparison group (35.1%) (p < .01) but did not differ from either the high exposure group (46.9%) or the FSU comparison group (46.4%), according to the post-hoc tests. The total number of hospitalizations in the low exposure Chernobyl group (2.35) differed from the immigrant (1.73) and Israel comparison group (1.26) (p < .01) but did not differ from the FSU comparison group (1.73) or the high exposure group (2.10). Low exposure women showed higher rates of circulatory hospitalizations (33.8%) compared to immigrants (22.8%) and Israeli born (16.5%), while high exposure women (27.5%) only differed from Israelis (p < .01). Neither exposure group differed from FSU immigrant women on the rate of circulatory hospitalizations. Post-hoc tests showed that among women in the low exposure group, there was a significant difference in rate of hospitalizations for neoplasms (28.6%) compared to the three comparison groups; FSU (18.6%), immigrants (15.7%) and Israel (13.1) (p < .01). Those among the low exposure group who were over the age of 20 at the time of the accident showed the higher rates of circulatory (51.2%) and neoplasm hospitalizations (33.3%), compared to the other immigrant groups (p < .01). When controlling for both age at accident and gender, hospitalizations for neoplasms were higher among Chernobyl-exposed populations (RR = 1.65, RR = 1.77 for high and low-exposure groups, respectively) compared to other FSU immigrants (RR = 1.31) other immigrants (RR = 1.11) and Israeli born (RR = 1.0) after controlling for gender and age at accident. High RRs attributable to Chernobyl exposure were also found for circulatory diseases compared to other immigrants and Israeli born (RRs = 1.50, 1.47 for high and low exposure compared to 1.11. and 1.0, other immigrants and Israeli born, respectively). Endocrine problems and disorders of the eye also showed elevated RR compared to the immigrant comparison groups. Respiratory and mental disorders did not show any consistent association with Chernobyl exposure. The findings support unique Chernobyl morbidity associations only in some diagnostic groups, particularly for low exposure women. General immigration effects on hospitalizations compared to the Israeli born population were found on all diagnostic groups. There is a need to improve the services and medical follow-up for these Chernobyl exposed groups in specific diagnostic groups.

Keywords: Chernobyl; Gender and age effects; ICD-10 diagnostic groups; Immigration effects; Nuclear accident; Radiation.