[en] The effect of formation of single-strand non-reparable breaks in the DNA chain of plasmid pBR 322 under picosecond laser UV irradiation with the intensity of approximately 10¹³ W/m² and lambda = 266-316 nm is studied. The breaks are shown to result from two-step excitation of DNA bases as well as from the formation of two-photon water radicals. The lower limit of quantum yield of single-strand breaks formation is approximately 10^-5 - 10^-6. (Auth.)

[en] It is established, that in number of populated areas of Semipalatinsk region soils (villages: Dolon', Kajnar, Sarzhal) contains technogene plutonium. Data shows, that ^239/2^40Pu is concentrated in soil layer depth 15 cm. It activity for Sarzhal is about 5000 Bq/m², for Dolon' is 10400 Bq/m², for Kajnar is 6200 Bq/m². Air contamination with both the β- and the γ-radiation radionuclides is insignificant. But most danger for human health presents soil dust with size less than 10 μm, containing plutonium isotopes. This dust is inhaling in human body and then it is accumulating in internal organs and bones. That is cause of numerous genetical (chromosomal), oncological and other pathologies

[en] The mechanism of inactivating action of high-power picosecond laser UV radiation (266 nm) on the lambda and phiX174 bacteriophages and pBR 322 plasmid has been studied. It has been shown that at UV radiation intensities from 10¹¹ to 10¹³W/m², inactivation of viruses and bacterial plasmids occurs mainly on account of single-strand breaks in the DNA chain unlike the case of less powerful UV radiation where the inactivation is associated with the formation of pyrimidine dimers. (author)

[en] It is performed the detailed investigation the health status of Semipalatinsk region population affected by constant radioactive irradiation during 40 years. The special attention attached to such pathologies as cancer, congenial defects of development and pathologies of cardio-vascular and nervous systems. It is also characterized the children health status. (author)