Progress report of the main studies up to January 1st 1969

Summary: this report reviews certain research which has been carried out in 1968 in the laboratories of the Aerosol and Mines Croup. In the field of aerosols, progress has been made on production, capture, and observation processes both from the fundamental point of view and from the point of view of applications to the radioactive contamination of buildings and to non-radioactive atmospheric pollution. In the field of fission gases and aerosols, a more complete study has been made of the effects of radiation on the iodine-containing products liable to be formed; the application to the trapping of these products has been examined.