Long-term effects of low doses of ionising radiation on Chernobyl clean-up workers from Latvia

Around 6000 inhabitants (20-49 years old in 1986) of Latvia took part in clean-up work in Chernobyl from 1986 till 1991. Most of them were officially documented as recipients of ionising radiation exposure (1-50 cGy). ABM (a 3-aminobenzanthrone derivative developed at the Riga Technical University, Riga, Latvia) has been previously shown to be a potential probe for determining the immune state of patients with different pathologies. The first study (using ABM) of Peripheral Blood Mononuclear Cell (PBMC) membranes of Chernobyl clean-up workers (n-97) from Latvia was conducted in 1996-1997. In 2006-2007 we examined the same (n = 54) individuals. Lipid peroxidation, ABM and ANS spectral parameters in PBMC suspension, fluorescence anisotropy and blood plasma albumin characteristics were recorded. In 1997 screening showed five different patterns of fluorescence spectra, but in 2007 we obtained only four. These patterns of spectra had never been seen previously in healthy individuals or patients with tuberculosis, multiple sclerosis, rheumatoid arthritis, etc., examined by us. The patterns of ABM fluorescence spectra were associated with membrane anisotropy and conformational changes of blood plasma albumin. It is necessary to note that all investigated parameters significantly differed in the observed groups of patients. These findings reinforce our understanding that the cell membrane is a significant biological target of radiation. These studies reveals a progressive trend towards certain resemblances to PBMC membranes of chronic B-cell lymphoid leukaemia and protein coformational alterations.