Synergistic effects of atmospheric releases of radioactive gases and SO2 in inducing nucleation in the atmosphere

The paper deals with a study related to the combined effects of SO2 and ionizing radiations in the formation of condensation nuclei in the atmosphere. Estimates of beta dose rate in the air for normal releases of 41Ar, short-lived noble gases and tritium from reactor stacks, and releases of SO2 from fossil-fuelled power plants are presented. Experimental studies carried out include spontaneous formation of condensation nuclei in the filtered air and correlation of the formation rate with ambient levels of SO2, radon and 41Ar. It has been shown that the combined effect of SO2 and ionizing radiations can give a larger production of condensation nuclei than normal photo-oxidation of SO2 in sunlight. Mechanisms of nucleus formation and possible atmospheric effects of increasing the background concentration of condensation nuclei have been discussed in relation to their role in inadvertent modification of local and global climate. The need for extensive basic research and field studies to establish control measures for any possible climatic impact of future large-scale use of nuclear power has been emphasized. (author)