Unstable-type Chromosome Aberrations in Lymphocytes from Individuals Living near Semipalatinsk Nuclear Test Site

Abstract

The Semipalatinsk nuclear test site area is considered to have been highly contaminated with radioactive fallout during 40 years of continuous nuclear testing. Individuals living near the nuclear test site are considered to have been exposed to both internal and external radiation. In order to assess the effects of prolonged radiation, a chromosome analysis was performed in lymphocytes from 123 people living in three villages, Dolon, Sarjar and Kaynar, and 46 control people in Kokpekty. A micronucleus assay was also conducted in 233 people in six different contaminated villages and one control village. Frequencies of dicentric and ring chromosomes were higher in residents of the contaminated area (1.55-2.56 per 1,000 cells) than those of the non-contaminated area (0.78 per 1,000 cells). Frequencies of dicentric chromosomes with fragments were also higher in the exposed group (0.44-0.96 per 1,000 cells). Among residents of the four villages, the incidence of multiple complex chromosome aberrations (MCA) was 0.03-0.34%. Incidences of micronucleus were also higher in the exposed group (9.36-12.3 per 1,000 lymphocytes) than the non-exposed group (7.25 per 1,000 lymphocytes). The higher incidence of unstable-type aberrations such as dicentric, ring chromosomes and micronuclei found in residents of contaminated areas seems to be mainly caused by internal exposure and other factors.

Epigenetics in radiation biology: a new research frontier

“…The 1986 Chernobyl accident led to a significant elevation in the rates of various cancers, including but not limited to, thyroid carcinoma, leukemia, and lymphoma (Gluzman et al, 2005; Balonov, 2007), breast cancer (Pukkala et al, 2006; Prysyazhnyuk et al, 2007), as well as bladder cancers (Romanenko et al, 2000; Morimura et al, 2004). In addition, elevated cancer and mutation rates were also reported in people living near the Semipalatinsk nuclear test site in Kazakhstan (Salomaa et al, 2002; Tanaka et al, 2006). …”

The micronucleus assay as a biological dosimeter of in vivo ionising radiation exposure

“…As a consequence, the CBMN assay is often used as a general toxicology test (7). However, because ionising radiation is a strong clastogenic agent, and thus a potent inducer of MN, the CBMN assay has proven to be a very reliable, thoroughly validated and standardised technique in the field of radiation biology (i) to evaluate in vivo radiation exposure of occupational, medical and accidentally exposed individuals and (ii) to assess individual in vitro radiosensitivity or cancer susceptibility (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23). Radiationinduced chromosome aberrations such as MN observed in PBL are mainly the result of unrepaired or misrepaired doublestrand breaks by the non-homologous end joining (NHEJ) repair pathway (22,24).…”

Studies of Health Effects from Nuclear Testing near the Semipalatinsk Nuclear Test Site, Kazakhstan

“…Biological samples from individuals living in the affected areas have been collected in numerous studies; 6 – 11 however, to our knowledge, not all were stored. In recent years, the National Research Institute of Radiation Medicine and Ecology in Semey started collecting blood samples and teeth from the persons still residing in the villages close to the former STS and stored them in a biobank.…”

“…4 , 5 There have also been numerous biological studies published on radiation effects. 6 – 11 The European Commission has funded a new project to assess whether it is possible to create a unified cohort of individuals affected by the atomic bomb testing, 12 which, if successful, could provide numerous insights into the health effects of radiation exposure. Beyond giving an overview on already published evidence, this paper provides recommendations about future research directions on radiation health effects.…”